study unit manufacturing processes, part 4 · an introduction to manufacturing organizations 1...

Study Unit

ManufacturingProcesses, Part 4By

Thomas Gregory

Manufacturers must organize and manage resources to maxi-mize the profitability of their operation. Global competitionhas caused significant changes in the way business is con-ducted and managed, especially in two areas: manufacturingstandards and product quality. Increased emphasis on product quality means that almost every manufacturer mustnow rely on a quality assurance (QA) program and embracedefined quality standards. Controlling the manufacturingprocess requires extensive use of technical communicationand management tools, many of which are directly imple-mented by technicians. In fact, manufacturing technicianscan significantly influence their company’s ability to prof-itably produce high-value goods.

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When you complete this study unit, you’ll beable to

• Understand and describe the basic functions of manage-ment and the principles on which work is organized in amanufacturing business

• Understand and describe various types of productioncontrol systems

• Describe the basic concepts behind modern production systems

• Explain how modern QA systems affect the manufacturingprocesses and product and process quality

• Understand how modern network-based communicationstechnologies will affect the manufacturing process nowand in the future

AN INTRODUCTION TO MANUFACTURING ORGANIZATIONS 1

Scientific Management 3Early Work Organization 3Factors of Production 11

MANUFACTURING FORMATS 14

Types of Manufacturing Production 14Equipment Layout 19

AUTOMATION AND MECHANIZATION 29

Evaluating Automation 30Automation Strategies 34Industrial Robots 35

MANUFACTURING MANAGEMENT SYSTEMS 46

Just-in-Time (JIT) Manufacturing 47Lean Manufacturing 49Quality Management and Quality

Assurance Systems 51eManufacturing 60The Future of Manufacturing 64

SELF-CHECK ANSWERS 67

EXAMINATION 69

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1

AN INTRODUCTION TO MANUFACTURING ORGANIZATIONS

In your previous studies you’ve learned about many impor-tant aspects of manufacturing materials and processes, andfactors that determine efficient and effective production practices. For any given product, a wide variety of materialchoices and manufacturing methods are available, but in apractical manufacturing environment, these choices some-times come with constraints that are beyond the engineer’s ortechnician’s control. A manufacturing company must organ-ize and manage its resources in a way that maximizes thevalue of those resources and the profit from production. Themost efficient organization of a manufacturing business dependson many factors, including business location, type of product,production volume, availability of skilled labor, governmentregulations, and market competition.

In recent years, especially since access to the Internetbecame widespread after 1994, communications and datamanagement techniques have become more sophisticated,resulting in globalization of industries. Globalization hasresulted in greater marketing opportunities for U.S. compa-nies and, perhaps more importantly, for other businesseslocated in less developed countries around the world, such asIndia, China, and Southeast Asia. Along with an expandedmarket, U.S. and European companies are also experiencinggreater competition in businesses where manual labor orlower-level technical help is significantly less expensive abroad.

Manufacturing Processes,Part 4

Manufacturing Processes, Part 42

You’ve probably noticed the number of products now usingmetric dimensions, and seen product directions printed inmultiple languages. American manufacturers are adoptinginternational measurement standards to gain more access tointernational markets. QA programs are spreading, too. We’vehad QA programs in specific industries in this country formany years, such as the nuclear power industry. Today,many companies are adopting internationally recognized QAsystems such as ISO 9000.

As a manufacturing technician, you need to be aware ofindustry trends that will affect both your job and your company’s ability to produce high-value goods. You’llundoubtedly work under a QA system that regulates manu-facturing processes, and you may be called on to use moreextensive technical communication and management tools. Inthis unit we’ll discuss some of the more important conceptsthat relate to managing production systems.

Operations research is the general term used for the study ofmanagement of manufacturing processes, with the generalgoal of maximizing the effective use of business resources.

As we go to our jobs on a regular—probably daily—basis, wetend to overlook some of the larger aspects of what we do,why we do it, and who tells us how to do it. We have skills we bring to a job, and our employer expects us to use thoseskills to the best of our ability to further the company’s goals.Many jobs have written job descriptions, which are detaileddescriptions of all the responsibilities and skill requirementsa particular position demands. These documents are usuallywritten with the cooperation of the management, the directsupervisors of the employee, and the human resourcesdepartment, which oversees the legal aspects of hiring andfiring personnel. Our work is organized for us, and we seldomgive any additional thought as to how we got to where we are.However, by studying developments in work organization andthe evolution of modern manufacturing organizations, we canlearn how all of the pieces fit together to make a competitiveand profitable organization in an increasingly global economy.

Manufacturing Processes, Part 4 3

Scientific Management

The term scientific management was first applied to earlyresearchers’ attempts to examine the tasks done by workers inearly factories, and to use the analysis of the results to improvethe organization of work. Frederick W. Taylor (1856–1915)was one of the early pioneers in this area, and his rigorousobservations and astute analyses were recognized as havingimportant consequences for the organization and manage-ment of factories of his day. Eventually, his and others’ workevolved into the recognized discipline of industrial engineering,which is an important engineering category today. In the nextsection we’ll discuss how the organization of work evolvedfrom early manufacturing models to today’s modern factory,and how managers have attempted to improve the productivityof various work arrangements.

Early Work Organization

The work of people has been organized in many ways sincebefore written history, perhaps even beginning with the separation of people into “hunters,” “gatherers,” or “farmers.”Early communities were governed by a chief or other leaderwho made the decisions on expected work “assignments” andthe division of goods produced, captured, or otherwise acquiredby the group. In a sense, this was the first managementstructure developed by humans: an autocracy (rule of one)based on physical power.

As societies became more complex, people’s work becamemore specialized, and more members in a group were con-cerned with a particular product or developing certain skills.Think about the people who were the first farmers, potters,weavers, or sword makers. For small groups, individualscould probably do all of the tasks necessary to manufacturetheir products. However, as the number of people in a group,community, or state grew, a demand for increased quantitiesof products resulted in a further separation of duties andskills. In medieval times, the concept of apprenticeship arose,where younger members of a group or family learned theskills of the master by first doing menial tasks, and latermore complex and important tasks as their skills increased.


Apprentices were the beginners in a trade, journeymen wereintermediate-level skilled workers, and masters were theexperts. We still apply these categories to many trades now inexistence. Work in these organizations was directed by themaster, and many masters of a trade in a given region wereloosely governed by a guild, an organization of craftsmenengaged in similar occupations who communicated informallyabout issues related to their businesses (Figure 1).

Organization of work on a larger scale was probably firstdone with the development of class structures in society.Increasing division of labor in larger societies was caused bythe development of a government in which the principal rulerdidn’t have direct authority over individuals, but insteadentrusted supervision and authority to appointed managersor bureaucrats. Distinct economic classes soon developedthat determined who did what, and under whose direction.Children born into an economic class were likely to staythere, and families were often confined to specific occupa-tions, passed down from father to son for generations. If youthink about our personal naming conventions, you can seeremnants of this practice in surnames such as Potter, Smith,Weaver, or Cook.

MasterMason

MasterWright

MasterCarpenter

JourneymanMason

JourneymanWright

JourneymanCarpenter

ApprenticeMason

ApprenticeWright

ApprenticeCarpenter

Trade Guild

FIGURE 1—In medievaltimes, apprentices pro-gressed from trainees tojourneyman level andeventually joined theloose confederation ofmasters within a guild.


The Romans wrote some of the first management texts about the division of labor on their estates. Their survivingtexts specify the desired number of supervisors, farmhands,animal tenders, and slaves required for estates of various sizes.For landowners who owned several estates, a bailiff, or steward,supervised the various farms as well as the allocation ofresources such as slaves. Different farms often specialized indifferent crops, resulting in more complexity. In the construc-tion of large buildings and civil works projects, workers wereorganized in gangs that specialized in different tasks. All wereunder the direction of overseers, and they in turn were underthe supervision of the master builder, who was a person ofhigh prestige and importance in early societies. The Romans’superb roads, bridges, and aqueducts are evidence of theirskill in managing resources and labor.

The Industrial Revolution

The growth of larger towns, cities, and states caused additional demands for manufactured products. This was primarily because of four factors: the growth of wealth fromtrade and exploration; the larger markets represented by thepopulation growth and its concentration in towns and cities;the introduction of new products by creative craftsmen incompetition with each other; and the development of newtechnologies. These four elements eventually led to the devel-opment of the factory system for producing manufacturedgoods. As you may recall, factories were locations where laborand resources were brought together to allow more efficientmanufacture of goods. Establishment of factories was basedon the acquisition of land, labor, and capital by businessmenseeking to make money through capitalistic economic practices. Early factories were concentrated in the textileindustries. In England, changes in banking practices madeaccumulation of wealth and its availability as capital moreattractive to those willing to risk investment in large-scalemanufacturing operations.

The success of early factories was due to the division of laborinto specialty areas, where individual laborers performed onlyone or two specific tasks, sometimes aided by mechanization.The new technology of steam-powered equipment and


improved machine tools greatly increased the productivity ofindividual workers gathered in a factory environment, buteven when new technology wasn’t used, manufacturing and assembly operations were greatly improved by labor specialization and assembly-line techniques. Factories werephysically laid out so that the work flow was logical andworkers didn’t have to move to different areas. Where multi-ple products were made, either the workers dealt with minorproduct variations or else additional lines were added.

Mass-Production Methods

You’ll recall that many of technology’s advances were drivenby the urge to achieve military superiority, and that many ofthe techniques for producing high-quality goods rapidly weredeveloped for strategic reasons. In fact, armies were usuallythe greatest consumers of many types of manufactured goods.However, as commercial economic markets became availablewith growing populations and rising middle classes, factorymethods were used to make products intended for everyday useby consumers, a classification of the portion of a populationthat had disposable income—money over and above minimalliving expenses—that allowed them to buy labor-saving devicesor spend for recreational purposes.

Mass-production techniques were greatly assisted by thedevelopment of relatively sophisticated machine tools and the standardization of interchangeable parts. Standarddimensions for fasteners and other common parts improvedthe quality and reliability of products, and advances inextraction and metallurgy techniques improved both theproducts and the machines that made them.

Assembly-line techniques have often been credited toautomaker Henry Ford, but in fact they were used earlier inmeat-packing factories in Cincinnati and Chicago. By adoptingsimilar methods, in particular the practice of moving the workto the worker, Ford was able to reduce the number of man-hours needed to make an automobile to under 11/2 hours.This reduces manufacturing costs and increased marketpotential by lowering prices to consumers. His competitorswere forced to do the same in short order, and mass


production and assembly-line techniques were soon common-place in manufacturing businesses throughout the country.These manufacturing concerns all had several factors in common: manufacturing tasks were finely divided, and mostoperations required low skill; a larger supervisory structurewas required as the factories grew in size; and more engineers,accountants, and human resources people were required tomanage the large number of workers.

With more specialized people needed to run more complexorganizations, factories were internally organized to grouppersonnel with similar functions into departments supervisedby managers. The specialization of functions extended toother departments such as accounting, marketing and sales,as well as engineering. Figure 2 shows the managementstructure of a typical manufacturing business. Note the specialization of each department and the way each groupreports to the chief executive officer (CEO). Also note that the plant manager—the senior person that production personnel would report to—is not the person in charge of thebusiness, but is instead one of several executive managers. Infact, in some businesses the CEO, the chief financial officer,and other senior managers may not even be physically locat-ed at the factory site. Workers on the production lines wouldreport to a department supervisor (perhaps a shift supervisorif the factory runs 24-hour days), and the department super-visors would in turn report to the production supervisor(Figure 3).


Production Supervisor

Materials Manager

Test Engineering

InformationTechnology

FacilitiesManager

ManufacturingEngineering

Services

Sales Force

Customer Service

Production Managers

Accounting

HumanResourceManager

CADDesigners

Engineering Lab

DevelopmentEngineers

Plant Manager Sales and Marketing Manager

Chief Financial Officer (CFO)

Research and Development

Chief Executive Officer

(CEO)

QualityAssuranceManager

FIGURE 2—The management functions of a factory are divided into specialized areas. The people onthe executive management team report directly to the CEO.


While Ford and others’ assembly-line techniques were huge successes compared to prior practices, their successfocused more attention on the efficiency of the individualworker. The push to be even more efficient and competitivegave rise to a new field of study, industrial engineering,sometimes called operations research. A scientific approach to analysis of manufacturing tasks had already been done by

Other Departments Other Departments


Department ShiftSupervisor (2nd Shift)

Department ShiftSupervisor (1st Shift)

Department ShiftSupervisor (3rd Shift)

Worker Worker

Worker

Worker

Worker

Worker

Worker

Worker

Worker

Other Departments


Department Shift Supervisor (1st Shift)

Department Shift Supervisor (2nd Shift)

Department Shift Supervisor (3rd Shift)

Other Departments

FIGURE 3—Within the production areas, individual workers report to a supervisor, who in turn, reportsto a production supervisor. Technical problems are first reported to the supervisor, who determines theproper approach to find a solution, perhaps involving people from other departments as necessary.


Frederick Taylor, who recommended eliminating unnecessarymotions on the part of the workers, and dividing labor intospecialties. Taylor spent a lot of time measuring worker performance, analyzing tasks for essential components, and eliminating unnecessary steps, thus earning his generaltechniques the name of scientific management.

In 1909, researchers Frank and Lillian Gilbreth also studiedthe specific, detailed motions that workers made to assembleproducts, giving rise to the method of motion studies inindustrial engineering. Motion studies measure the amountof time workers actually spend on the task, as opposed tosetup, or gathering material and tools. Industrial engineeringlater came to include virtually all aspects of manufacturing,including plant layout, control of materials, division of tasks,and even product design. Industrial engineers are ofteninvolved in design for assembly, or DFA, when new productsare conceived and brought to a manufacturing environment(Table 1).

Table 1

DESIGNING MANUFACTURED PRODUCTS FOR EASE OF ASSEMBLY

• Identify critical part characteristics such as surface finish,

tolerances, and strength.

• Identify manufacturing factors to achieve critical part

characteristics.

• Determine process capability to achieve critical part

characteristics.

• Avoid tight tolerances.

• Minimize the number of machined surfaces.

• Design for easy inspection.

• Use standard manufacturing processes where possible.

• Minimize the number of reorientations during manufacture.

• Use generous radii and fillets on parts.

• Combine or eliminate individual part features to minimize the

number of parts per assembly.

• Design parts for easy jigging or fixturing.


Factors of Production

As more people are involved in the production of a productand manufacturing tasks are divided into specialized subtasksperformed by low-skill workers, some type of managementhierarchy must be in place to ensure they all meet theirresponsibilities for efficient production. In most manufactur-ing operations there’s a position called production managerwhose responsibility is to monitor and supervise critical pro-duction factors. These factors, shown in Figure 4, are the “fiveM’s.” You’ve already encountered four of them: men (includingwomen), machines, materials, and methods. A fifth factor,money, is added to these familiar factors of production.

Men. The production manager (PM) manages the peopleinvolved in the manufacturing process. He or she ensuresworkers maintain an acceptable work ethic, work well withother people, and have or acquire the necessary skills. ThePM is often responsible for writing job descriptions and moni-toring satisfactory performance of workers, and arrangingtraining when necessary.

ManufacturingSystem

Men(People)

Capital

Machines Methods(Processes)

Materials

Customer Requirements

Products

Waste

InputsOutputs

FIGURE 4—Manufacturing uses the factors of production organized bymanagers to produce finished goods from raw materials in processes thatadd value to the product at each step of the progression.


Machines. The PM selects the correct machines for each step,and ensures the machine is properly set up and well maintained.The PM generates and implements maintenance schedules tomake sure machines are in good working condition.

Materials. The PM arranges the flow of raw materials andwork-in-progress (WIP) to the proper machines at the righttimes. Information about the flow of materials and product is maintained by the PM and reported to the appropriate senior management.

Methods. The PM is responsible for selecting appropriatemanufacturing processes and technology and for arrangingthe effective use of the machines with proper scheduling.

Money. The PM’s concern with money is mostly related toinventories, which can represent a significant portion of acompany’s assets. Inventory control involves monitoring finished goods, work-in-progress, raw materials, componentparts, packaging materials, supplies, and even capital equipment used for production.

In general, the production manager must ensure a smoothflow of materials and work so that the company’s productiongoals are met at the highest quality level possible. The PMmonitors the progress of production against a plan, makingsure that the processes are optimized or making improve-ments where possible.

As a manufacturing technician, the most important thing foryou to remember about the factors of production is that all ofthe recent manufacturing techniques developed aim to con-trol these factors in a way meant to minimize costs andincrease quality and production rates. When you hear aboutmanufacturing methods such as kanban, just-in-time, or leanmanufacturing (each of which is discussed in this study unit)you need to ask yourself how this method works with each ofthe five factors. You may find that in the end, there are fewdifferences in the way each of the methods works comparedto others.


Self-Check 1

At the end of each section of Manufacturing Processes, Part 4, you’ll be asked to pause and

check your understanding of what you’ve just read by completing a “Self-Check” exercise.

Answering these questions will help you review what you’ve studied so far. Please

complete Self-Check 1 now.

1. The formal list of the responsibilities and qualifications for a manufacturing job is called a_______.

2. Study of manufacturing processes eventually evolved into a formal discipline called _______.

3. Before large-scale manufacturing production in factories, people just learning a trade or skillwere known as _______, and were taught by recognized experts in the trade.

4. A location where labor and resources were brought together for more efficient manufacture ofgoods is called a _______.

5. The appearance of consumers with _______ led to increased use of factories to produce goodsfor popular consumption.

6. The development of _______ for dimensions and measurement units greatly aided the evolution of mass production techniques.

7. Taylor’s observation and analysis of worker tasks, and his recommendations for improve-ments, came to be known as _______.

8. A _______ is the person in a factory whose responsibility it is to monitor and supervise criticalproduction factors.

Check your answers with those on page 67.


MANUFACTURING FORMATS

As more advanced manufacturing facilities developed duringand after the Industrial Revolution, different physical layoutsas well as work organization models appeared. Each type oflayout and organization has advantages and disadvantages,and astute production managers and business owners arequick to adopt elements that suit their particular industryand products. Also, different product types and productionvolumes often dictate within fairly tight constraints how theproducts are made. A manufacturing shop that specializes in prototypes will look very different from a high-volume bicycle shop, for example. While the system of classificationdescribed here is tidy, you’ll find that there’s much overlap in actual practice.

Types of Manufacturing Production

Manufacturing production types can be broadly classified intofour different categories that depend for the most part on theproduction volumes and types of products: job shop, batchmanufacturing, mass production, and continuous production.Production planning and control is quite different for eachtype, but all have benefited from the efforts of such industrialengineering pioneers as Taylor and the Gilbreths. Figure 5shows a rough breakdown of production types based on production quantities.

Job Shop Production

Job shop production can occur in very small and very largemanufacturing businesses, as the products of this type ofproduction format range from simple, one-of-a-kind itemslike replacement parts for antiques, to things as complex ascomponents used in the construction of a ship or a bridge.These products are often made to order on a custom, or atleast an infrequent, basis. Small job shops often supply partsto larger job shops, and maintain adequate production vol-umes only by establishing a reputation among these largerentities for supplying high-quality parts in a timely fashion.


Some job shops acquire a reputation for working with spe-cialty materials, such as refractory metals like tungsten andmolybdenum, or hazardous materials such as beryllium.Working with these specialized materials requires specialtechniques and equipment. In general, successful job shopsrequire a wide range of machines and equipment to deal withunanticipated production demands. Because they need to beflexible, job shops normally carry high levels of raw materialinventory and supplies. They also require highly skilled per-sonnel who can adapt to nonrepetitive manufacturing tasksand projects. For example, sales and engineering personneltend to be adaptable and cross-trained in several disciplines,especially for smaller job shops, which seldom have theresources to hire specialized engineers or technicians. Many

Increasing Quantity

Increasing Variety

1 10 2500 100,000

Production Volume

Process Manufacturing

Mass Production

Batch Production

Job-Shop Production

Continuous Production

Discrete-PartProduction

FIGURE 5—Although these classifications overlap considerably, different manufactur-ing formats lend themselves to different types of production volumes. In general,high production volumes are often achieved by sacrificing flexibility.


projects are prototypes or feasibility trials and may neverhave been done before, which adds to the experience andexpertise needed by job shop staff.

Batch Production

Batch production is the manufacture of similar products,such as bicycles, electric motors, or computers, to meet acontinuing market demand. These types of products aren’tusually made on an as-needed basis, but they’re produced inquantities based on projected demands and stored untilthey’re delivered to the end user. Storage and packing aretherefore important considerations in planning and control ofbatch manufacturing operations. Batch sizes can vary fromsmall to large, and the work-in-progress is always large.Batch production usually uses general-purpose machinetools, and production planning must be as efficient as possible to minimize the number of machine setups andmovements of material to different workstations.

An advantage of batch production is the ability to monitortime and dates of manufacture of critical components.Tracking batches and lots by date and serial numbers allowsmanufacturers to recall and repair products that fail in service. Car manufacturers have long been able to recall cer-tain vehicles for repair or replacement of critical componentssuch as gas tanks or alternators, and toy manufacturershave done the same for toys that break in ways dangerous tosmall children.

Mass Production

Mass production is the manufacture of very large numbers of identical components or assemblies that are needed on a continuous basis, such as cars, appliances, or evenmachinery. Complex products such as cars may have multiple mass-production sites producing component partsin parallel, and moving them to an assembly location to makethe finished product. Raw materials are fed into these sys-tems at preplanned rates to ensure continuous production,while minimizing work-in-progress as much as possible.


Failure of any part of a mass-production system can havesevere consequences, so maintaining some inventory is necessary.

Tasks in a mass-production facility are divided into simple,easy-to-do operations, assisted by sophisticated machinesand tools. This has the advantage of requiring only low- tomedium-skilled help, and promoting high levels of productconsistency and uniformity: the machines are responsible formaintaining the product quality, not their operators. The dis-advantage of this labor division is that it’s very difficult tochange machines and equipment should the system need tobe modified, and highly skilled labor is needed to maintain,troubleshoot, and program the machines. Production plan-ning must be nearly perfect because it’s extremely difficult to change the system, although the use of modern computer-controlled machine tools helps somewhat. Productivityincreases for mass-production facilities in the future are likely to come from more use of programmable machines thatcan do multiple tasks without human intervention.

Continuous Production

Continuous production is the manufacture of products thatare made using an ongoing process such as distillation orchemical processing. It’s mostly found in chemical and food-processing industries, although the production of wire couldbe classified as a mostly continuous process. The productionof gasoline is a continuous process, using heat to evaporatecrude oil fed to the evaporator, and then collecting gases andliquids that result from this evaporation.

Figure 6 shows the general relationship between expectedproduct quantities and flexibility in design for the formatswe’ve discussed. Table 2 summarizes and compares some ofthe critical characteristics of different manufacturing formats.


1 10 2500 100,000

Production Volume

Process Manufacturing

Mass Production

Batch Production

Job-Shop Production

Custom Designs Standard DesignsFle

xibl

eD

edic

ated

FIGURE 6—Increasing production quantities usually requires efficient dedicated equipmentto achieve high throughputs (or cycle times), and isn’t suited to variations or options.Smaller quantities can be customized at many points during the manufacturing process.


Equipment Layout

Identifying the correct layout of manufacturing facilities oftenrequires considering some specific aspects of the productsand processes that are in use or are being evaluated. In anexisting operation, the location of new equipment is unfortu-nately often determined by what free space is available ratherthan considerations of where it will be the most efficient. Ingeneral, a formal process of analysis and decision making

Table 2

MANUFACTURING FORMAT COMPARISONS

Terms of

ComparisonJOB SHOP ASSEMBLY LINE

CONTINUOUS

PROCESS

Typical Products: Furniture/Engineering Automobile/Electronics Beer/Cement

Capital investment Low Medium High

Overheads Low Medium High

Direct workforce:Skills Skilled Low Semiskilled

Direct workforce:Numbers High Medium Low

Materials to laborratio 60:40 70:30 90:10

Nature of order Make-to-order Make-to-stock Make-to-stock

Scheduling Backward Forecast stock replenishment

Forecast stock replenishment

Product variety High Medium Low

Product changes Frequent Routine Occasional

Inventory location Work in progress Components/Finishedgoods

Raw materials /Finished goods

What do people buyfrom us? Competence Quality product Consistent products

Qualifiers Quality (functionality/competence) Quality (reliability) Quality (conformance)

Winners Lead time Price / Brand Price

Low priorities Cost Lead time Flexibility

Major waste areas Inventory/Scrap Downtime / Rework Downtime / Yields


should be done to determine the most appropriate factoryand equipment layout. A recommended process would be as follows:

Step 1. Identify objectives: What should the new or changedlayout accomplish? How can you quantify or measure thoseobjectives? How will new technology or techniques improvecapabilities, products, or efficiencies?

Step 2. Identify product families: Product families are prod-ucts that are basically the same and are manufactured bysimilar processes and equipment. Product families usuallyshare much of the same equipment.

Step 3. Map the processes: A process flow chart should be generated for each product or product family. Process flow charts are diagrams showing each work center, thesequence of operations, material flow, and informationreporting requirements.

Step 4. Process improvements: New equipment and technologyshould be implemented in a way that takes advantage of newfeatures and capabilities. This is an iterative process, occur-ring on a regular basis. Managers must constantly analyzethe how and why of existing processes as new technologiesbecome available and others become less efficient.

Simply automating an existing process may not take fulladvantage of new technologies, and may actually be counter-productive for the most effective manufacturing processes.

Step 5. Improve housecleaning: Eliminate clutter and unneed-ed items; organize and identify materials and equipment; cleanwork areas and install signage; train employees in house-cleaning procedures. This so-called 5S method stands for Sort,Set in Order, Shine, Standardize, and Sustain, a workplacechecklist for daily improvement.

Step 6. Reduce setup times: Define the steps for eachprocess and machine; identify the steps that must be donewhile the machine is stopped and those that can be donewhen it’s running; duplicate tooling and fixtures where possible to eliminate waiting; try to eliminate or reduceunnecessary steps.


Step 7. Analyze constraints: Identify internal and externalprocess constraints: material limitations, inadequate processes,worker skills and knowledge, and available space.

Step 8. Process simulation: Sophisticated computer software can simulate manufacturing processes and evaluate alternatives.

Step 9. Analyze relationships: Make a diagram that lists the work centers in the manufacturing process, and create a matrix that identifies those areas that need to be closetogether. List the work areas on the horizontal and verticalaxes. At the intersections of the rows and columns, rank the importance of having the areas physically located closetogether. Some reasons why areas may need to be close:shared supervision, shared personnel or equipment, ease ofmaintenance or service, communications requirements, andsafety requirements.

Step 10. Develop the layout: Diagram the positioning ofwork centers, offices, storage areas, rest areas, and any otherimportant functional areas. Try to optimize the importantrelationships established above.

An organized approach to work area layout will lead to increasedefficiencies, and may result in combining the types of layoutsdiscussed in the next section.

The physical arrangement of the capital equipment and machinetools necessary to manufacture a line of products can greatlyinfluence the efficiency of the manufacturing process and thefundamental cost of production. Industrial engineers willstudy many variations of machine placement for current andprojected production quantities before a plant design is finalized.Once an arrangement has been implemented it’s very difficultto change without expensive modifications. Over the years,four basic equipment layouts have used regularly used:

• Functional layout

• Cellular, or group, layout

• Flow line layout

• Build-in-place


Functional Layout

This type of equipment arrangement is probably the oldest aswell as one of the most common, especially for job shop andbatch production. Figure 7 shows a typical layout of machinetools arranged by type, and an example of work flow for abatch of parts. An advantage of this type of arrangement isthat supervision of each area can be specialized; that is, thesupervisor in charge of the milling machines can be an expertin milling processes, milling machine setup, and perhaps evenprogramming of CNC (computer numerical control) mills.

Functional layout is very flexible and is therefore suited forprototyping and one-offs, job production, or small batch pro-duction. Throughput time (sometimes called cycle time), thetime it takes from start to finish of a manufacturing operation,can be quite high because of the amount of handling requiredto move parts from machine to machine. Setup time can besubstantial because of the different requirements of eachbatch of parts. For batch production, there’s usually a largeamount of work-in-progress, making inventory costs high.

Turning Department

Batch of Components

Drilling Department

Grinding Department

Indicates Actual Work Location

Milling Department

Inspection Department

Indicates Components’

Path

FIGURE 7—A functional layout with similar machines located in the same area is efficient for smaller job shops and batch production methods. For larger quantities,material and personnel travel time limit efficiency in this type of layout.


Cellular Layout

As the capabilities and sophistication of CNC machines has increased, cellular layouts have become more popular.Figure 8 shows an example of a simple manufacturing shopwith a cellular layout containing several machining cells. Thekey feature of a cellular layout is that all of the machinesnecessary to make a specific component, or family of compo-nents, are located in one area, so material handling is muchsimpler. Depending on the degree of automation within thecell, material handling can be done with industrial robots,minimizing the need for human labor within the operation.

Assembly Department

Inspection Department

GrinderPlanerLathesSawMill

Cell A

Cell CCell D

MillDrillLatheHoning Machine

LatheGrinder

MillDrills

Coordinate MeasuringCNC Machining Center

Parts-Cleaning Machine

Cell B

FIGURE 8—Cellular layouts tend to improve quality as well as production volumes due to theclose proximity of the machines, the operators, and the cell supervisors. Material travel timebetween manufacturing steps is significantly reduced.


Cellular layouts require high product volumes to justify theircosts, and automated handling and assembly can be veryinflexible if they must be adapted to meet product variations.However, with more sophisticated communication and control, machines can be made to work with a range of variations or options, allowing some customization withinhigh-volume manufacturing operations. Figure 9 shows asophisticated robot of the type that’s now being used to loadand unload machining centers.

For businesses where these layouts are efficient, there aremany advantages to a cellular layout:

• Cellular layouts promote team spirit, and members of agroup are more likely to pull together to make their par-ticular operations successful.

FIGURE 9—Robots workfaster and more consis-tently than human operators.


• Members of the group are usually capable of performingall the required functions within the cell, which allowsfor job rotation, minimizes boredom, and ensures contin-ued production even if one of the members is absent.

• Supervision of cells is tighter and administrative paper-work is minimized. The supervisor can make sure thatall parts produced are at the quality level desired.

• Work-in-progress and inventories are greatly reducedbecause of the cell specialization and work flow.

A major disadvantage to cellular layout, other than its cost, isthat each cell is set up to produce one particular part orassembly, and while programming and sophisticated auto-mation can increase the number of variables the machinescan deal with, significant product changes would requireredesigning and reequipping the cell. Also, flexibility betweencells often isn’t good, and maximum machine utilization isn’tguaranteed, since the usage of a machine in each cell isdetermined only by the tasks assigned to it in that cell. Alathe in one cell may be used only a few hours a day, while asimilar lathe in another cell is in constant use.

Flow Line Layout

Flow line layout is most similar to the mass-production linesfound in automobile factories like the ones Henry Ford built.When a product has a continuous demand, as is the case fortrucks and automobiles, flow line layout offers the highestproduction rates of any factory process. A specially designedarrangement of equipment and machines, called a transferline, can perform a set of grouped tasks, with the outputproduct sent as a finished good or transferred to another flowline to incorporate into a more complex product. Figure 10shows an example of a transfer line that can be set up in twoconfigurations. A flow line can be completely linear, or it canbe made U-shaped, reducing the amount of floor arearequired. In a U-shape, one operator can perform multipletasks on different sides of the U.


A disadvantage of flow lines is that if one operation breaks down,the whole line stops; flow lines therefore often have areas ofbuffer stock placed at likely locations to keep the line operat-ing should something go wrong at one of the stations. Thisobviously increases the work-in-progress inventory and asso-ciated costs. Flow lines aren’t usually used where a lot ofconsumer choice is required, since a flow line layout can’teasily deal with product variations. A flow line is expensive toset up, so it wouldn’t be used for products whose life cycle isshort. Cars, for example, have a full model year of productionand changes to next year’s model are often minimal. On theother hand, cell phones, clothes, and toys change continuously,with styles changing frequently due to customer preferences.

Sawing Turning Boring MillingDrilling

andTapping

Grinding FinishingFinal

Inspection

Raw Material Input

Component Output

Linear Layout

Sawing Turning Boring Milling

Drillingand

TappingGrindingFinishing

FinalInspection

Raw Material Input

ComponentOutput

U-Shaped Layout

Drillingand

Tapping

FIGURE 10—Flow line layouts use transfer lines to move materials between manufacturing operations.Alternatively shaped layouts can be used to save space and labor time.


As we’ve said, some flexibility can be built into flow lines withthe use of programmable (and reprogrammable) robotic devicesthat can be adapted to product ariations. This decreases thetime to reconfigure the line to produce another product.

Build-in-Place

Some manufactured products are so complex or so big that it isn’t feasible to move the product through a line, and thelabor and materials are brought to a single site. This is thecase for products such as ships, bridges, or spacecraft.Houses are another type of product built on site; however,manufactured housing is done in factories set up with flowlines as discussed previously.


Self-Check 2

Complete the following statements.

1. The main factor that determines the manufacturing format is _______ .

2. The most likely manufacturing format for producing product prototypes would be _______.

3. Comparing the people employed in job shops and mass production lines, those in _______ manufacturing are more likely to have multiple skills, making them versatile.

4. Moderate production volumes produced in _______ manufacturing facilities usually requiregeneral-purpose machine tools.

5. Tasks in a _______ facility are divided into simple, easy-to-do operations, assisted by sophisticated machines and tools.

6. Gasoline and chemicals are made using _______ manufacturing formats.

7. The manufacturing format that has the largest capital investment costs is _______

8. Production labor in _______ manufacturing formats is likely to have the highest skills.

9. A checklist tool for workplace housecleaning is known as the _______ tool, and is used toimprove the appearance and function of the work areas.

10. Placing machine tools with similar functions in the same location in the factory is called a_______ layout.

11. _______ is the total time it takes to manufacture a product in a factory.

12. Grouping all of the machines necessary to make a single assembly or part is called _______ layout.

13. _______ layout can be linear or U-shaped to save shop floor space.

14. Construction of the space shuttle Atlantis was probably done with a _______ manufacturingformat.



AUTOMATION ANDMECHANIZATION

You may find it hard to believe, but the number of manufac-turing jobs has been decreasing steadily since the latter partof the twentieth century, even though the number and varietyof products has increased. That’s because fewer workers areproducing more goods of higher quality than ever before. Themajor reason for this increase in productivity has been theincreased use of mechanization and automation. As automated processes became more common, manufacturingwages have increased and the number of hours worked perstandard workweek has decreased from 60 to 40.

Many people think mechanization and automation are thesame, but they aren’t. Mechanization is the replacement of a human action by a mechanism. Automation also meansreplacing human action by a machine, but with the addedability to control the action remotely. The word “automation”was first used in the automobile industry in the late 1940s todescribe the increased use of automatic devices with controlsin the car assembly lines. Automated machines are usuallycontrolled by a closed-loop system, where the process ismeasured and compared with the desired value, and adjust-ments made to the system based on the difference. Figure 11shows a simplified diagram of a closed-loop control system.

You can further classify automation by noting whether themachine is designed with fixed functions or whether it’s programmable. Fixed-automation machines are designed forspecific purposes, often with mechanical devices such ascams, levers, or gears. Making fixed-automation equipmentperform other tasks requires extensive and expensive modifi-cations. By contrast, programmable automation can changeits function and required tasks by changing the computerprogram that controls the equipment. Sensors provide feed-back to a computer about the position, velocity, acceleration,and applied forces of the actuators that move machine toolcutters, welding heads, or robotic arms. Some “smart” actua-tors have embedded sensors that constantly send informationabout machine activities back to a controller. Sometimesthere’s even a “supervisory” computer that monitors and


controls many other computers in a production line. Use ofprogrammable automation such as the PLC controller shownin Figure 12 can enhance the flexibility of a manufacturingsystem by allowing machines to deal with desired variationson every piece that moves through the production line.

Evaluating Automation

Automated equipment can benefit many types of manufactur-ing formats, but whether it will be profitable depends on anumber of factors:

• Assembly costs

• Production rates and quantities

• Availability of skilled and unskilled labor

• Life cycle of the product

• Cost of automated equipment and the extent of automation desired

Controller Process(Actuators, Machines)

·+

_

Control SignalError Signal

Sensing Elements

Feedback Signal

Output(Actual Condition)

Summing Amplifier

Input(Desired

Condition)

Measures Positon, Velocity, Temperatures,Pressure, Part Count, etc.

FIGURE 11—A closed feedback loop enables automated machines to be precisely controlled by humansor by programmed computers. Sensing elements measure the condition of the output and feed it backto a summing amplifier that compares the actual output with what’s desired. An error signal is fed toan amplifier, which generates a control signal used to manipulate the actuators, machines, or otherprocess machines.


The many advantages of automation include labor cost savings, increased production rates, better product qualitythrough consistency, and safe operation in hazardous ortoxic environments. Disadvantages of automated systemsinclude their cost, but also less flexibility in many cases, andmore susceptibility to interruption or damage from faultyparts. Parts fed into automated equipment must be of consis-tent quality and in the correct “presentation” to avoid linebreakdowns from defects that a human operator could easilyremove or fix. Surveys indicate that the greatest cause ofautomated-machine stoppage is faulty or out-of-spec partsfed to the machine.

FIGURE 12—Programmable logic controls (PLCs) can control machines as well as supervise other computers, allowing easy changes in sequences, robot or machine motions, or the timing of differentprocesses.


Effective use of labor resources is a key factor in manufac-turing profitability. Eliminating expensive, skilled labor performing routine tasks is one of the ways automation hasthe potential of improving the efficiency of production opera-tions. Here’s a general analysis of the cost effectiveness of anautomated system compared to a manual one. This analysistakes into account the cost per unit for each:

• Automated unit cost = (cost of part transfer systems +cost of feeding and placement devices + machine costs) �production quantity

• Manual unit cost = [(number of operators � average wage �time to make production quantity) + (cost of equipmentfor manual manufacture)] � production quantity

Comparing these values will yield insight as to whether or not automated systems can successfully improve profitability.This economic analysis is very rough, and many details andcircumstances need to be added to the above general categories.Other circumstances may also affect decisions, such as theavailability of skilled labor for equipment operation and tech-nical support. Figure 13 shows the relative costs betweenmachined parts for various types of machine tools comparedto the production quantities needed.

10 100 1000 10,000 100,000 1,000,000

Manual Machine Tools

CNC Machine Tools

Flexible Manufacturing Systems

General-Purpose Automated Processes

Special-Purpose Automated Processes

Production Quantities

Rel

ativ

e M

achi

ning

Cos

t per

Pie

ce

FIGURE 13—The production quantities required will have a significant effect on the cost ofautomation as well as the range of practical manufacturing formats.


Automation will have a major impact on an existing workforce if it displaces many employees, resulting in unpredictable and hard-to-measure human-resource costs.Workers would be more socially isolated as well as beingrequired to assume new and perhaps more mundane responsibilities. But labor costs may decrease significantly,production rates may greatly increase, and workers withgreater technical skills must be hired to maintain, adjust,troubleshoot, program, and upgrade automatic equipmentsuch as robotic welders (Figure 14).

FIGURE 14—Robot controlsand programming requireskilled technical people whounderstand both the processand the automation controlsused to perform the work.


In general, it’s not always the best policy to automate everythingin a manufacturing operation. Automation should be used onlywhen it makes economic sense. Automated systems lend them-selves well to very large production rates while maintaining highand consistent product quality. As we’ve mentioned before,automated systems can work in toxic or dangerous environ-ments where people shouldn’t. Parts produced by automatedsystems are high quality, and changes in a process can occuronly with changes in the programming or adjustments of themachine controls. The lead times of every automated processcan be precisely known, and the overall time to complete aproduct will be greatly decreased. These give the business theability to “make-to-order” rather than maintain large invento-ries in anticipation of future orders. All of these effects areaccompanied by a greatly increased capacity to monitor pro-duction functions using tracking information provided by themachines and the computers that control them. A final advan-tage of automated equipment is that some products such asturbine blades and electronic wafers are so complex that onlyprecisely controlled machines are capable of making them.

Automation Strategies

Implementing automated factories is a capital-intensive taskrequiring large amounts of money and human resources, andthe cost of the automation must be covered by the increasedproduction and profit over a reasonable payback period. Inconsidering where and how automated machinery could beused, the following questions could serve as a guideline:

• Could multiple operations be performed on the same partby the same workstation? Could multiple operations beperformed simultaneously, such as drilling multiple holes?

• Could several workstations be combined functionally intoa work cell with the use of automatic handling equipment,allowing a continuous flow of production?

• Would a specially designed, fixed-purpose machine builtto perform one or more operations with great efficiencybe economically viable?


• Could the machine or the workstation be made flexible,i.e., able to perform different but similar tasks to accountfor options or variations in manufacturing processes?Could the machine be reprogrammed quickly to handledifferent product lines with little setup or layout change?

• Would robotic handling devices reduce material-handlingtime, material movements, or setup times?

• Will the use of computer controls increase data collectioncapabilities and therefore decrease management responsetime to changing situations?

• Can common databases be developed in CAD and designsoftware that can be used by all factory departments, suchas planning, purchasing, production control, engineering,and sales?

Industrial Robots

In high-volume production environments, the use of robotsfor material handling and placement is often necessarybecause of the extremely repetitive motions required or thelow cycle times needed for the equipment. In other applica-tions, the robot is actually doing the work or holding thework tool, such as a welding or paint-sprayer head. Several different types of industrial robots are prevalent inmanufacturing businesses. These include the continuous-path and the pick-and-place types.

In general, robots are classified by thenumber of axes of available motion.Figure 15 shows the possible axes of move-ment, which are the three linear axes oflength, width, and depth (X, Y, and Z); androtation about these three axes, making atotal of six possible movements. A robot’srange of motion is limited to one or more ofthese six directions, with few robots capableof moving in all six of them. The moremovements possible, the more complex andcostly the robot. Figure 16 shows a robotfor a welder capable of several rotational

Z

Y

XC

A

B

FIGURE 15—Possible Axes of Motion


motions that can combine to give translation in the X, Y, or Zaxes, even though there’s no direct movement of the machinein these axes.

Pick-and-place robots have motions limited to movement betweenone fixed point and another, or a start and finish point. Theycan precisely “pick” a part or assembly at one location and“place” it at another; their motion isn’t controllable in between.Pick-and-place robots usually have only two to four axes ofmotion, and are usually driven by hydraulic or pneumaticcylinders. Because of their simplicity, pick-and-place robotsare usually the least expensive type. Figure 17 shows an

FIGURE 16—This weldingrobot can perform complicated motions toproduce rapid, consistentwelds.


example of a pick-and-place robot used to take parts from amoving conveyor line and move them to a work-station for amachining operation.

Continuous-path robots often can move in multiple axes. Theirheads move in precise three-dimensional paths, as might beneeded for painting or welding. They have position and velocity control (second-order feedback loops) and are oftencontrolled by electrical actuators, which can be more easilycontrolled by computers. Some types of continuous-pathrobot can be programmed for motion by “teaching” it thepath: a human operator will move the head through thedesired motion, and the resulting path is digitized and storedin the computer memory. Mathematically, the computer willtake a series of coordinate points and construct a path ofmotion that’s placed in memory. The speed of the head dur-ing each portion of the path can also be varied depending onrequirements. Figure 18 shows a six-axis robot that can be

Conveyor Line

Parts Ready for Milling

Milled Parts

Pick-and-Place RobotCNC Milling Machine

FIGURE 17—Pick-and-place robots load and unload machine tools quickly and accurately. This one hastwo axes of motion, one linear and one rotational.


used to load and unload a machining center. Figures 19 and 20show different head styles used for specific tasks, such aswelding, painting, or securing parts to another location.Figure 21 shows other common forms of industrial robots.

Waist Rotation

Shoulder Rotation

Elbow Rotation

Wrist Rotation

Gripper Mounts HereWrist Bend

Rotation

FIGURE 18—This robotcan be used for manytypes of applicationsbecause of the greatflexibility in its possiblemotion. The workinghead isn’t shown, but itcould be a gripper, weld-ing head, or paint gun.


FIGURE 19—This robot head is a gripper with multiple “fingers” that allow it to securely holdparts as they’re transferred to a machining center.


FIGURE 20—This robot has a welding head for automated TIG (tungsten inert gas) welds.

Pick-and-Place Rotary Robot

Workchanger Robot

Part Trays

Universal Robot

Gantry Robot

FIGURE 21—Robots can be made in many different sizes and config-urations to do specifictasks. Unlike humans,robots aren’t confined tojust one shape.


Although not usually thought of as simple robots, material-handling systems often perform similar motions. Many work-transfer stations prepare parts or assemblies to be handledby robots prior to the manufacturing operation, as shown inFigure 22. For example, a hopper may contain a quantity ofsmall parts that are oriented and fed by a parts feeder to arotary indexed transfer table. The robot will pick these parts offand place them onto the table for the next operation. Transferstations can also have many different configurations, andthey’re particularly useful for assembly operations wherehuman operators may take the parts off the line for assemblyinto the product. Figure 23 shows three common types oftransfer stations: rotary, rectangular (or U-shaped), and linear.

FIGURE 22—These robots are an important part of this transfer station, removing parts from trays totransfer them to a machining-center robot for a milling operation.


Parts Feeder

WorkheadParts Carriers

Indexing Table

Rotary Transfer(A)

Parts Feeders

Completed Assembly

Parts Carriers

Base Placed in Position

Workhead

Empty Work Carrier

U-Shaped Transfer(B)

Workheads

Partial Assembly Moves to Next Station

Part Carrier

Parts Feeders

Buffer Stock

In-Line Transfer(C)

FIGURE 23—Often not assophisticated as robots,transfer stations performmany of the same functions, and they’reparticularly useful formoving small parts orassemblies.


There are five main considerations in choosing a robot for anautomation application:

• Size—Not just the physical size and footprint of the robotitself, but also the maximum weight it can lift at the mostextended position. Some modern robots can lift andmanipulate more than 1200 pounds. Figure 24 shows a robot capable of lifting moderate to heavy loads.

• Reach—The maximum distance that mechanism canextend and the overall envelope of the possible paths the working head can traverse.

FIGURE 24—This robot has a long reach that allows it to move large distances. Counterweightingallows it to lift and manipulate heavy loads.


• Speed—The maximum velocity with which the workinghead can move as well as maximum acceleration rates.This relates closely to the size of the robot, in that thegreater the mass at the moving head, the greater theforce that must be applied to start the head moving or to change its direction quickly. Modern robots can havemore than 20 feet per minute of precisely controlled head speed for applications such as painting, gluing, or welding.

• Number of axes of movement—This will depend on the typeof robot and the complexity of the tasks it must perform.

• Power source—Some robots require electric, pneumatic,or hydraulic power, or combinations of these. Powersources available in the factory may limit the selection of types or vendors.

In selecting robotic systems, the auxiliary equipment andtools must be considered in the final cost analysis. Thesecould include pallets, conveyor lines, hand tools, pallet equipment, and software options. Calculation of the finalcosts can be compared to the possible savings achieved overthe equivalent nonautomated processes used to produce thesame production volumes.


Self-Check 3


1. One of the biggest factors in reducing the workweek in the early part of the twentieth centurywas the use of _______.

2. A control system that senses the output of a system and uses it to adjust the input is called a_______ feedback system.

3. A type of automation usually done with gears, cams, or levers is called _______ automation.

4. _______ can enhance the flexibility of a manufacturing system by allowing machines to dealwith desired variations on every piece that moves through the production line.

5. Automated production systems lend themselves to _______ production rates and _______environments where people can’t work.

6. The decision to buy automated equipment is determined in large part by the _______ periodfor capital invested in the equipment.

7. Robots can move in _______ possible axes of movement.

8. Movement of parts from a conveyor line to a machining center and then replacing them on theconveyer is usually done by a _______ robot.



MANUFACTURING MANAGEMENT SYSTEMS

You’ve learned that jobs in manufacturing are decreasingeven though manufacturing productivity has increased. Themain reason for this has been the pressure from more andmore competitive industries and the use of advanced tech-nologies to improve the entire product development cycle,from conception to delivery to the customer. Remember, man-ufacturing is the process of taking raw materials and addingvalue through inputs of other resources such as labor, capitalequipment, and land, and then making a product available tothe customer. Customers’ desires drive the market, and man-ufacturing responds to the product demand shown by theirwillingness to pay a given price for a product. Manufacturersmust respond to the market and compete with other busi-nesses that offer the same or similar products. To maximizeefficiency, and therefore profits, manufacturing managersand theorists have looked at every phase of the product cycleto seek competitive advantages.

Among the many buzzwords related to manufacturing sys-tems, the central theme is the control of the manufacturingenvironment to maximize efficiency, lower costs, and increaseprofits. Two management systems that you’ll hear about are“just-in-time” and “lean manufacturing.” Just-in-time systems began several decades ago in the mid-1970s; leanmanufacturing evolved in the 1990s as a response to theintense pressure for profitability in a more global economy.

It’s important for you to recognize and understand thesemanagement systems because you’ll probably be working inan environment using one or more of these techniques. Properimplementation of these systems involves all employees, soyou’ll be called on to contribute to improving efficiency to thebest of your ability. You’ll also undoubtedly be involved in sometype of quality assurance system that controls and managesprocesses and procedures that affect the quality of the partsand products.


Just-in-Time (JIT) Manufacturing

The concept of just-in-time (JIT) manufacturing was devel-oped by Taiichi Ohno, a Toyota production manager. Hestressed the delivery of the proper amount of parts or materials, just in time for their use, and only as they’re needed. The JIT process resulted in major cost savingsbecause it eliminated excess work-in-progress inventory,which can be enormous in large manufacturing businesses.Ohno went from assembly shop supervisor to vice presidentof the Toyota Motor Corporation in 1975 and helped itbecome the one of the largest auto manufacturers in theworld, challenging (and in many markets surpassing) GeneralMotors and Ford.

Implementing JIT suddenly made cash available due to invento-ry reductions; factory response time improved significantly;and many products could be built to order, ensuring theywould be sold rather than remaining in inventory.

The successful application of JIT involves constant control ofquality at every operation, since faulty parts leave productionlines stalled from lack of parts. JIT also requires close atten-tion to supplier quality issues and constant communicationwith vendors and customers to ensure precise coordination ofrequirements and deliveries. Today, the term supply-chainmanagement refers to the effort to control the flow of materi-als all the way from the customer’s order to the raw materialsupplier. Modern communication methods using the Internethave made great strides possible. You’ll hear the termeManufacturing to describe the use of the Internet and computers to control manufacturing operations. In the idealsituation, a manufacturing firm can fill orders directly fromcustomer information, and place orders for the raw materialsor component parts based on supplier inventories that arecommunicated directly via the Internet. Firms like UnitedParcel Service (UPS) have built supply-chain managementservices to help small manufacturing businesses that don’thave the resources or expertise to develop good systems ontheir own.


Another term closely associated with the JIT system is kanban. The Japanese word kanban means “card” and refersto the way the amount of work-in-progress (WIP) is controlledin a factory. Cards or tickets are attached to parts, batches,or pallets to monitor their location in the manufacturingprocess. When the supply of a part is depleted at a work center, its card is returned to the source to be refilled, butonly when new parts are needed. The number of cards pres-ent control the total work-in-progress inventory, preventingexcess parts from being produced by any work area. You mayhear kanban described as a production control system, butits origin and implementation is very close to JIT. Figure 25shows a segment of a manufacturing process that’s con-trolled by kanban. The goal of this system is to “pull” as fewparts as possible with the kanban card, which will reduce thework-in-progress inventory level, and minimize the bufferstock needed.

Producing Process

(Needed Quantity)

Kanban Card

Consuming Process

Buffer Stock

Signal

Completed Product

Maximum number of parts in buffer stock is determined by natural variations in the process.

FIGURE 25—Kanban Control for Just-in-Time Manufacturing


Lean Manufacturing

Lean manufacturing, which grew out of the automotiveindustry, has been called a new model for manufacturing,and is based on the principle of eliminating any operationthat doesn’t add value to the product. It can be applied to allaspects of purchase, design, development, and manufactureof any product. As a management philosophy, it focuses onreducing seven types of wastes: overproduction, waiting time,transportation, overprocessing, inventory, motion, and scrap.

Manufacturing systems are typically either “push” or “pull”systems. In traditional “push” systems, customer orders trig-ger the inputs to a production line to begin to manufactureparts. But problems arise if an earlier operation is faster thana later one, excess inventory will pile up in front of the down-stream machine. Inventory is a form of waste—it takes upspace, can be damaged or devalued, and uses up workingcapital. The ideal place for inventory is at the end of the production process, waiting to fill customer orders. But eventhat inventory should be only what’s necessary to cover confirmed orders.

Implementing a “pull” production system that works fromdemand of products and parts from early parts of the pro-duction areas is a key feature of lean manufacturing. In alean system, a customer order places a demand on the ship-ping department to ship orders, which places a demand onthe warehouse to package and ship products, which places ademand on the assembly areas to finish assemble the product,which places demands on the flow lines or cellular areas tocomplete subcomponents, and so forth. The customer ordercauses demand ripples to flow through the factory from theoutput side to the input sides.

People who work extensively with lean manufacturing con-cepts recognize that many costs become relatively fixed whena product is designed. This is because engineers tend tospecify familiar, safe materials and processes rather thaninexpensive, efficient ones. This tendency to use establishedand well-known materials and methods reduces the likeli-hood of project failure, but at the expense of innovation and


lower costs. One way to avoid designed-in costs is to use concurrent engineering, a technique that puts product devel-opment in the hands of a development team, as opposed to asingle design group. A concurrent engineering team will con-sist of members from the design, manufacturing, sales andmarketing, purchasing, material control, and even shippingdepartments. As shown in Figure 26, serial product develop-ment activities are avoided and instead occur in parallel, withthe next steps beginning before the last ones are completelyfinished. Successful organizations develop and review check-lists to review product designs to ensure that hidden costsdon’t get built into a new product design.

Design

ManufacturingMethodologies

Setup

ProductionSerial Activities

Design

ManufacturingMethodologies

Setup

Production

ShorterTime-to-Market

Concurrent Engineering Product Development

Parallel Activities

Traditional Product Development

Time

FIGURE 26—Concurrent engineering enables many people to have inputs at all phases of productdevelopment, assuring that costs aren’t “designed in” and become unchangeable at later steps in themanufacturing process.


Some key lean manufacturing principles that are imple-mented in real factory applications are as follows:

• Perfect first-time quality—A concerted attempt to achievezero defects in parts and assemblies, and to find andsolve problems with existing processes early.

• Minimize waste—Eliminate all activities and materialsthat don’t add value, and increase the use of resourcessuch as capital, people, and land.

• Continuous improvement—Reduce costs, improve quality, increase productivity and information sharing.

• Pull material flow—Products are “pulled” through a factorysystem from the customer end, not “pushed” from theproduction side of operations.

• Flexibility—Produce different mixes or a greater diversityof products quickly, without sacrificing efficiency at lowervolumes of production.

• Supply-chain management—Develop and maintain long-term relationships with known, quality suppliersthrough risk sharing, cost sharing, and informationsharing arrangements.

• Lean manufacturing processes—Whether they occur indesign, manufacturing, or distribution—are all about get-ting the right things, to the right place, at the right time,in the right quantity while minimizing waste, being flexible,and responding quickly to changing conditions.

Quality Management and Quality Assurance Systems

In the end, manufacturing must always respond to marketconditions and customer demands. In the increasingly globalmarkets of the late twentieth and early twenty-first centuriesand the competitive pricing of consumer and industrial prod-ucts, product quality is critical. Customers look closely atproduct pricing and will choose value over simple price inmany instances, evaluating both what the product costs andits apparent overall quality. Two products of comparable


quality are chosen by price structure (or brand preference),but where quality clearly differs, price becomes less of a factor in a purchase decision.

You’ll hear many different terms that refer to quality issues,and you need to know what they mean. Here are official definitions of quality system, quality control, and qualityassurance published by ANSI/ASQC Q90-1987, QualityManagement and Quality Assurance Standards:

• Quality system—The organizational structure, responsibilities, procedures, processes, and resources for implementing quality management

• Quality assurance—All the planned and systematicactions necessary to provide adequate confidence that aproduct or service will satisfy given quality requirements

• Quality control—The operational techniques and activitiesthat are used to fulfill requirements for quality

Note that these definitions don’t try to define what quality is,only the methods used to achieve a quality defined by cus-tomer requirements. However, over the last several decadesthe meaning of the word “customer” has been expanded toinclude internal customers as well as buyers of the end product. For example, the internal customer of a particularmachining cell could be the plating department. Quality man-agement systems will also address how the machining cellcan address and solve quality problems in the “products” itsupplies to the next user of its output. In an organizationaldefinition of quality, all departments that interact with othersare both “suppliers” and “customers” until the product actually reaches the consumer.

Manufacturers have developed sophisticated quality assur-ance (QA) systems to control the manufacturing processes, sothat the highest-quality products are made consistently.Achieving high quality in all phases of the manufacturingmethods has several advantages for businesses:

• Products are more competitive with competing models of similar features because of customer perceptions of value.

• Product deliveries are faster.


• Scrap and rework costs are lower, with less raw materialwaste and non-value-added labor.

• Work-in-progress inventories can be lower, reducinginventory costs.

With such important factors determined by the success of the QA system, business leaders tend to put great emphasison developing effective QA methods.

A good quality assurance system plays a key role in theorganization and day-to-day operations of the factory. Itsfunctions include

• Documenting quality processes and procedures—In everydepartment from design to shipping, work must be performed in accordance with proven procedures thatproduce mistake-free work. The procedures are docu-mented and changes are approved after review by appropriate departments. The QA system is documentedin a formal QA plan, approved by company management,and followed by all departments.

• Translating quality specifications—Customer require-ments are interpreted and implemented in every process.Special requirements are controlled by approved proce-dures for maintaining component identification throughthe manufacturing process. Procedures are specified anddocumentation is maintained by the factory to assurethat the correct procedures were used.

• Maintaining instrument standards—All measurementequipment, such as meters, gauges, tooling, and instrumentation, is maintained in proper and traceablecalibration condition. Documentation for calibration andrepairs is maintained for all equipment that measuresproduct performance in any way.

• Process capability studies—Manufacturing machines,equipment, and processes are analyzed to determine the highest level of performance possible with a givencombination of machines, materials, and workers.


• Data collection—Manufacturing performance data is collected for quality control analysis with tools such asstatistical process control (SPC). Records are maintaineddocumenting process performance for auditing, warranty,or liability purposes.

• Failure mode and effect analysis (FMEA)—FMEA cananticipate the likelihood of events and consequences forproduct failures, and procedures can be implemented thatlessen the consequences of those failures that do occur.

• Disposition of nonconforming material—Products or partsthat are out of specification are isolated by controlledprocedures to prevent their being used in or mixed withgood products. The source of the defects are isolated andsolved to prevent future failures or scrap.

• Manufacturing processes verified—Critical processes suchas welding or assembly procedures are “qualified” to ensurethey’re suitable for the design. The use of qualified pro-cedures is documented for all manufactured products.

Given the importance of the quality management systems forproducing quality products at competitive cost, quality man-agement personnel have moved to ever-higher positions inbusinesses, often becoming vice-presidents. These managersare responsible for the total quality management within the organization.

Some of the more important characteristics of total qualitymanagement systems include a strategic plan; education andtraining for every employee; the use of quality measurementsand statistical methods to measure performance and processcontrol; objective customer satisfaction measures; and bench-marking all business processes and products to comparethem with goals, or against known leaders in the business.Figure 27 shows a diagram of the basic framework of a totalquality management plan and many of the major components.


ISO 9000—An International Standard

Many manufacturing firms have their own QA plans that arewritten just for their business; others follow standards devel-oped and maintained by organizations such as the AmericanSociety of Mechanical Engineers (ASME), or the InternationalOrganization for Standardization (ISO), with its well-knownISO 9000 series of QA standards. Having a good QA system isof great value to a modern manufacturing business. Participationin recognized QA systems such as the ISO 9000 is voluntary,but in some cases—when work is performed for governmentagencies or with government funds, for example—product orperformance specifications for implementation of a recognizedQA system practically has the power of law.

The International Organization for Standardization was foundedin 1946 in Geneva, Switzerland, to establish worldwide com-mon standards for manufacturing, communications, and trade.More than 90 countries currently participate; the AmericanNational Standards Institute (ANSI) is the body that representsthe United States. The organization’s 180-odd subcommitteesdraft standards with the help of technical advisory groups,and have issued more than 8,000 standards in most areaswith the exception of electrical and electronic engineering.

TotalQuality

Management

Quality Management

Quality Assurance

Quality Control

Inspection Metrology

FIGURE 27—Most qualitymanagement systemsaddress all of the majorfunctions of a business,whether a manufacturing orservice-type business. Plansshould emphasize measuredperformance, accuratedata, and feedback to correct system flaws.


One reason that the ISO 9000 quality standards have becomeso important is that in the late 1980s, the European coun-tries developed a common market, where any country couldbuy and sell products with the others while maintaining con-sistent quality and performance. Common standards reducedinspections and acceptance test costs when products weresold in other European countries. With the adoption of thesestandards, U.S. products sold in the European communityhad to conform to the same standards or risk significant economic penalties. Since then, many major American companies have adopted the ISO standards to develop ormaintain European markets, and also because the standardsare viable frameworks for developing superior QA systems.

The ISO 9000 series is like other such systems in manyways. It requires a documented QA manual that addresses allaspects of the business: contract review, design verification,purchasing methods, material control, the use of certified orapproved procedures, written work instructions, control ofnonconforming items, and internal and external qualityaudits. An ISO 9000 plan involves all levels of personnel,from the president or CEO down to the machine operators(Figure 28).

There’s a big difference between adopting the standards andbecoming certified to the standard. Any company can adoptthe standards to implement a QA system. However, certifica-tion involves asking an outside accrediting body to examinein detail the company, its operations, and its plan, in order toformally recognize its compliance with the standard. Thereare hundreds of independent accrediting agencies in theEuropean community. In the United States, the only accredit-ing body was the Registrar Accreditation Board, until it wastaken over by ANSI in 2005.

Six Sigma

Another QA system you’ll hear about is called Six Sigma, aquality management program that focuses on improvementsto a company’s performance by identifying and eliminatingdefects in its processes. The name “six sigma” comes fromthe use of statistics and the normal distribution curve thatdescribes the way variation occurs in random processes.


Management Elements

Core Process Elements

Foundation Elements

DocumentedQuality System

Training Quality Audits

Management Responsibility

Customer Order

Contract Review

Purchasing

ProcessControl

Control of Non-

ConformingProduct

HandlingStorage

PackagingDelivery

Shipped Product

Inspection and Testing

Quality Records

Corrective Action and Prevention

Product Identification and Tracebility

Statistical Techniques

Document and Data Control

Control of Inspection and Test Equipment

Inspection and Test

Total Quality Management Requirements

Warranty and Service

Design Review

and Control

FIGURE 28—ISO 9000 quality assurance plans involve every area of a business and all levels of per-sonnel. The plan is based on extensive and accurate record keeping, and measured product data.


When you graph measurements taken from any process, trulyrandom—not caused by any external factors—variations(measurements that differ from the average) will clusteraround an average value and in a predictable pattern. From a group of previous process measurements, it’s possible tocalculate a value, called Sigma, which shows how much anynew measurement is likely to differ from the process average.In six sigma, a defect is defined as any measurement that dif-fers from the process average by six times sigma. Statistically,this value is unlikely, meaning that defects will only occur ata rate of about 3.4 defects per million measurements, whichrepresents a very-high-quality process.

The use of the term six sigma has moved away from themathematical definition and has been applied to any productor process that satisfies customer requirements and minimizesproduction costs to achieve a maximum value to the business.

Six Sigma was pioneered by Motorola Corporation in the mid-1980s and has been adopted by other major manufacturerssuch as General Electric, Ford, Microsoft, Caterpillar, andRaytheon. Initially applied only to manufacturing, Six Sigmasystems are now spreading to other types of businesses as away of implementing total quality management systems.

Six Sigma systems use several methodologies to achieve low-defect processes and products, as well as to develop newcustomer-focused products. The chart below summarizesthese tools.


As you’ll recognize, many Six Sigma processes and tools overlap other types of quality assurance and quality controltechniques, and this has been one of the criticisms of SixSigma plans. However, the useful focus of these techniquesinto a manufacturing management philosophy has well-documented successes in the companies mentioned above, andits applicability to a wide variety of business organizationsmakes it especially attractive as a framework for improvement.

Table 3

SIX SIGMA METHODOLOGIES

Existing Processes and Products New Processes and Products

DMAIC

Define – Measure – Analyze – Improve – Control

DMADV

Define – Measure – Analyze – Design – Verify

Define who are the customers, what are therequirements, what are their expectations;project boundaries and the beginning and endof the process; the processes to be improvedby mapping flow and relationships.

Define goals of the design activity; what isbeing designed and why; goals that are consis-tent with customer demands and businessstrategies.

Measure the performance of the basic processes involved; develop a basic data collection plan; measure data from multiplesources to determine types and rates ofdefects; compare results to customer requirements.

Measure baseline abilities of current processesfor future comparisons; define critical measure-ment needs; translate customer requirementsinto project goals.

Analyze the data collected to determine possi-ble causes; gaps between performance andgoals; possible sources of variations

Analyze proposed processes for potential trouble spots and possible resolutions.

Improve the process by developing solutionsusing technology, training.

Design the process and product to meet cus-tomer needs with an effective use of resources.

Control implementing of improvements, document the changes; institutionalization ofthe improvements by training, staffing changesor additions or changes of equipment.

Verify the design performance and ability tomeet customer requirements and businessgoals.

Tools Used for Six Sigma Projects:

• Customer surveys • Regression analysis

• Process flowcharts • ANOVA (analysis of variance)

• Stakeholder analysis • Brainstorming

• Histograms and Pareto charts • Failure modes and effects analysis (FEMA)

• Statistical process control (SPC) • Cause and effect diagrams (Fishbone charts)


eManufacturing

No discussion of manufacturing management systems wouldbe complete without mentioning eManufacturing, the termapplied to the development and use of new communicationstechnologies in manufacturing processes. The driving forcebehind eManufacturing was the arrival of the Internet around1994 and the worldwide adoption of the communication standards that allow computers and other devices to communicate with each other, sometimes referred to asTransmission Control Protocol/Internet Protocol (TCP/IP).

If you think about how the Internet has affected your life already, you can imagine how it’ll affect manufacturingfirms in the future. Implementation of modern communica-tions and computer technologies will allow better control ofthe basic manufacturing functions, with benefits such asreduced inventories, better manufacturing throughput, betterdelivery performance, reduced paperwork, and improvedquality. Major manufacturing firms have demonstrated thatmoving to eManufacturing concepts can vastly improve theircompetitiveness.

Some of the technologies and products that are now com-monplace and have greatly impacted our lives are

• E-mail—We can instantly communicate over the entireglobe to exchange information. E-mail can be used tosend written instructions, pictures, software, music,electronic drawings, and documents.

• Wireless technologies—Cell phones and wireless devicessuch as the Blackberry allow voice and e-mail communi-cations in real time, unconstrained by location. A cellphone lets callers reach you almost anywhere in theworld at any time. Cell phone cameras let you send per-sonal or business-related photos. Business computersare being networked in wireless environments, avoidingthe use of expensive cables and the need to be physicallyconnected to the network.


• Computers—Modern computers are becoming smallerand more powerful, and better designed for the way wework: wireless hand-held devices function as organizers,note takers, and e-mail hubs; laptop computers aresmaller and more powerful, and can be used with pencil-like styluses as if you were writing on a paper tablet; andpowerful software exists for such business applicationsas simulation, engineering analysis, and 3D modelingand drawing.

• Data storage—In the mid-1980s, computers used harddrives that had storage capabilities on the order of 20–30megabytes. Today’s hard drives hold several hundredgigabytes and more, or 10,000 times the former capacity!New storage devices such as “thumb drives” and memorycards are used in media that have no moving parts.Availability of high-density memory and computer chipswill make many products “smarter” and more cost effectivein the future.

The impact of these technologies will have a significant influ-ence on manufacturing, both inside the factory and outside.Within the manufacturing environment itself:

• Critical decisions can be made instantly by key personnelat the appropriate level, wherever their location, withaccess to e-mail, cell phones, and pagers.

• Shop floor data collection is instantaneous, accurate, andavailable to everyone who needs it to make managementdecisions.

• Modern building automation systems program and manage temperature, ventilation, lighting, fire controland alarms, and security from remote locations. Buildingautomation systems have the potential to reduce energyconsumption within buildings to achieve thousands ofdollars in utility cost reductions annually.


• Manufacturing services that can be digitized and sent tolower-cost organizations are outsourced to save money.These could include design services, CAD drawing, man-ufacturing prototyping, accounting and payroll, andadvertising and marketing services.

• Inventory control and work-in-progress can be accu-rately tracked using RFID (radio frequency identification)chips embedded in or attached to products or materials.These tiny chips contain coded product information andeven allow tracking of lost materials. Retail chains andlibraries make extensive use of these chips for product ID and location.

How the business interacts with people and businesses outside the firm will be greatly affected by the ability to communicate rapidly and accurately. For example:

• Supply-chain management will be handled entirely bycommunications technologies and software. Customers canplace orders directly over the Internet, and orders canautomatically be generated to sub-vendors so that trustedsuppliers know when raw materials need to be furnished.Invoicing can be done electronically, shipping instruc-tions can be placed, and accounting transactions can berecorded without intervention from on-site personnel.

• Electronic file transfers can allow vendors to manufactureparts, assemblies, and prototypes without intermediatesteps. Electronic files can be sent over the Internet toapproved vendors, who then send the files directly tomanufacturing cells. Software can translate drawingsinto CNC program files to allow machines to make partsdirectly from electronically formatted drawings.

• Quotations for materials can be received electronically or online, with vendors bidding on items directly fromspreadsheets e-mailed or posted online.


• Manufacturing firms have access to vendors’ inventoriesand forecasts, to make accurate delivery predictions forwholesale or retail markets.

• Equipment suppliers can diagnose faulty machinesremotely, while machines communicate with othermachines for fault diagnosis, online corrections andrepairs, and upgrading software.

• Voice-Over-Internet Protocol (VoIP) is making audio communications as reliable as local telephone calls forreal-time communications with anyone in the world whohas access to a computer with a physical, wireless, orsatellite Internet connection.

These technologies will dramatically affect the way we liveand do business. Manufacturing businesses will continue to integrate new technologies in a way that make them morecompetitive and let them reach new markets. Companies thatdon’t switch to this new way of doing businesses will faceshrinking markets and higher costs. Figure 29 shows thestructure of a typical eManufacturing organization. Individualmanufacturing sites use information technology to improve theusual functions of maintenance, quality, and systems controlwith the use of accurate real-time data. Senior managers, whomay not be located at the same facility, often have access tothe same data to allow timely decisions about resources thataffect customers and suppliers. Order management and plan-ning and scheduling functions are even more tightly integratedto assure improved JIT manufacturing capability.

While there are definite concerns about the implementationof Internet-based communication, such as the cost of com-munication infrastructure and security, most businesses see them as the price of remaining competitive. As these technologies are incorporated, manufacturing employees willcontinue to require different workforce skills. Manual orsemiskilled machine operators must possess significant anddiversified technical and problem-solving skills. Each skilledemployee will continue to be an important component of themodern manufacturing facility, doing more with ever moresophisticated processes and machines.


The Future of Manufacturing

What changes will occur in manufacturing in the future?Many of the changes occurring now will continue and accelerate in the near future, as the quality of the new tech-nologies improves. We’ll see major growth in manufacturingcapabilities of other countries around the world such as India,China, Southeast Asia, and even Africa. As the economies inthese countries become more productive with higher quality,more manufacturing services and functions will be outsourcedto these areas with less expensive labor costs. The products

Suppliers Customers

Planningand

Scheduling

Senior LevelPlanning and

Administration

Order Management

Manufacturing Production Systems

Maintenance Control Systems Quality

Supply Chain

Management Level

Manufacturing Sites

FIGURE 29—Typical Structure of an eManufacturing Organization


we buy as consumers, such as automobiles, power tools,appliances, or cosmetics, won’t change greatly, but wherethey’re manufactured and at what price will surely be different.

What also will change are the products that are available. Forexample, research in nanotechnologies will undoubtedly pro-duce new products for consumption in the future. Researchersat Intel, a major semiconductor chip manufacturer, say thatmajor changes in chip technologies are necessary to signifi-cantly improve performance: we must be manufacturing atthe molecular level during the next decade if we expect tomaintain the current rate of technological advances.

Successful manufacturing of products on the nanotechnol-ogy scale will require advances in many disciplines such aschemistry, physics, mechanical engineering, materials science,molecular biology, and computer science. As we learn to workat the nano scale, we can expect new products to appear.Exciting possibilities of new medicines, miniature machinesto find and eliminate cancer cells, and miniature computersseem within reach when technological capabilities are pro-jected forward to the future. Scientists say that to have usefultechnologies, we’ll have to build machines that build evensmaller machines, and that useful large devices and productswill require massive parallelism—many machines working onthe same project at the same time. It’s possible to build verylarge objects using very small tools by having them worktogether in unison towards a common goal: a tree is a perfectexample of molecular assembly on this scale!

As you continue with your studies, remember that what youlearn today has a half-life, in much the same way as radioac-tive materials have a half-life. As technologies and techniquesprogress, half of what you know will be obsolete in just a fewyears. It makes sense to prepare yourself for a continuallychanging future by making a habit of learning new thingsany way you can, from formal coursework such as theseunits to studying trade magazines and technical journals.One thing is for certain: not only isn’t your education over, it may be just beginning!


Self-Check 4


1. One of the main advantages of JIT manufacturing systems is reduction in _______.

2. _______ refers to the effort to control the flow of materials all the way from the customer’sorder to the raw material supplier.

3. The method of using cards or tickets attached to parts, batches, or pallets to control theirlocation in the manufacturing process is known as _______ control.

4. A key principle of lean manufacturing is the use of _______ production systems instead ofpush systems.

5. An advantage of concurrent engineering is a reduced _______ for new products.

6. _______ within an organization is the philosophy and guiding principles that seek to continuously improve every aspect of a business.

7. ISO 9000 first originated in _______ as an acceptable QA system.

8. eManufacturing resulted from the introduction of the _______ around 1994, allowing rapidworldwide communications.


Self-Check 11. job description

2. industrial engineering

3. apprentices

4. factory

5. disposable income

6. standards

7. scientific management

8. production manager

Self-Check 21. production volumes

2. job shop format

3. job shop

4. batch

5. mass-production

6. continuous

7. continuous

8. job shop

9. 5S method

10. functional

11. Cycle time or Throughput time

12. cellular

13. Flow line

14. build-in-place

67

An

sw

er

sA

ns

we

rs

Self-Check 31. automation

2. closed-loop

3. fixed

4. Programmable automation

5. high, toxic or hazardous

6. payback

7. six

8. pick-and-place

Self-Check 41. work-in-place (WIP) inventory or costs

2. Supply-chain management

3. kanban

4. pull (demand)

5. time to market

6. Total quality management

7. Europe

8. Internet

Self-Check Answers68

69

1. Work transfer stations

A. often use simple robots for handling small parts. B. can’t be used when people remove the parts for

some portion of the assembly operation. C. utilize only the most sophisticated

six-axes-of-motion robots.D. are found only in build-in-place type

manufacturing facilities.

2. Just-in-time manufacturing was developed in Japan

A. for the transistor radio manufacturing facilities. B. to compete with job-shop manufacturing methods.C. to avoid shipping problems with raw material suppliers. D. to minimize WIP inventory costs and improve

automobile quality.

Ex

am

ina

tion

Ex

am

ina

tion


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Examination70

3. As the operator in charge of the CNC milling machine in a manufacturing cell, youdecide to make 100–200 parts more than are called for by your production manager to avoid future delays. Your decision results in

A. a typical benefit of job-shop style manufacturing.B. an increase in WIP inventory. C. decreased product quality.D. decreased manufacturing times and no delays.

4. Cellular layouts are effective in certain high-volume applications because

A. product quality isn’t dependent on worker skill. B. equipment use through all adjacent cells is easily optimized. C. material handling is simpler because of the proximity of related machines. D. cells usually don’t require close supervision.

5. You’re working in a finish-painting operation that’s undergoing a shift to lean manufac-turing methods. Your supervisor asks you to stop photographing the parts that are sentfrom your operation to assembly. He probably does this because

A. six-sigma inspectors can’t evaluate defects using photos.B. photos aren’t considered acceptable forms of documentation in ISO 9000

certified operations.C. your photos will interfere with the department’s JIT Quality system.D. photographing the parts doesn’t add value to the finished product.

6. As the supervisor of the assembly area in an electric motor manufacturing business,you notice that a group of motor housings has been rejected because of an oversizedhole in the side of the housing. Since the assembly bolts will go through without anyproblems, you remove the housings from the nonconforming material area and sendthem to the assembly department for use in the final product. Your decision to usethese parts will

A. save the company money.B. reduce the amount of reworked material and thus manufacturing costs.C. probably violate your company quality assurance procedures.D. save overall time and money as the end result.

7. A rural area in Pennsylvania has a regional population of 82,000 and an unemploymentrate of 8.9%. In evaluating the possible location of a large job shop in this area, one ofthe most important things you would need to consider would be the

A. availability of highly skilled workers in the available labor pool. B. availability of batch-style manufacturers in the area.C. number of assembly-line workers in other area manufacturing businesses.D. number of mass-production facilities in the area.

Examination 71

8. A technician in a manufacturing cell reports a faulty velocity sensor on an actuator. Ofthe following, he or she is most likely referring to a problem with a component on a(n)

A. aircraft-servicing scaffold. C. ship-building work platform.B. programmable robotic welder. D. mass-production conveyor line.

9. A quality assurance technician has collected performance data about the defects pro-duced by a certain milling machine in a factory producing high-cost aviation parts. The data indicates that the machine produces parts with truly random variations in thecritical dimensions, and no operator-caused variations. The next step the technicianwould take after collecting this data would be to

A. try to improve the machining process by adjusting feeds and speeds or other manufacturing parameters.

B. contact a manufacturing engineer about advanced machining process capabilities todecrease variations.

C. analyze the process for potential trouble spots.D. determine if the variations meet customer specifications at an acceptable level.

10. A supplier of specialty prototype parts made from beryllium is likely to have_________ as a manufacturing format.

A. cellular layout C. assembly lineB. job shop D. functional shop

11. While arranging for the installation of three new milling machines, you have a questionabout the best placement positions for the machines and their loading robots. For thebest answer you would go see the _______ of the factory.

A. industrial engineers C. CFOB. product designers D. QA managers

12. Production managers must monitor and supervise critical factors such as

A. QA audits, shipping schedules, and order entry.B. line maintenance, customer relations, and returned goods.C. worker training, equipment layout, and WIP inventories. D. capital costs, machine inventory, and value-added calculations.

13. The main factor that determines how manufacturing businesses are classified is the

A. cost of the equipment. B. number of employees needed to run the machines.C. number of machines and equipment necessary for production. D. production volumes anticipated.

Examination72

14. Fixed-automation devices

A. aren’t used in modern factories. B. use mechanical means such as cams and gears to accomplish tasks. C. can be easily changed to programmable automation if necessary.D. can’t be used in automation on flow lines.

15. Mass production advantages include

A. low capital costs and low WIP. B. low-cost machine tools and high cycle times.C. consistent product quality and low-skilled labor requirements.D. rapid product customization and high production volumes.

16. A method used to control work-in-progress by signals sent back to producing areas forreplacement stock is

A. JIT. C. TQM.B. kanban. D. DFM.

17. A robot needed to do a complicated three-dimenstional welding operation

A. would likely be a one-axis pick-and-place model. B. would have either one linear or one rotational axis of motion. C. would likely be a continuous-path type robot.D. isn’t yet commercially available.

18. In automated manufacturing systems, smart actuators

A. are those that operate without the need of controllers.B. can easily replace fixed automation devices to increase production rates.C. can increase cycle times and decrease WIP.D. have built-in sensors for position and velocity control.

19. One reason for extensively automating a manufacturing process is that

A. low-skilled labor is inexpensive and easily available. B. production volumes are low. C. operations must be done in a hazardous environment. D. all prototype-building operations are highly automated.

20. A robot that can move a hand left and right and rotate the hand 360º is said to have_______ axis (axes) of motion.

A. one C. threeB. two D. four

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