MANUFACTURING SYSTEMS

- Abilash.S

JH - 2

Manufacturing is the process of converting raw materials, components, or parts into finished goods that meet a customers expectations or specifications. It commonly employs a man-machine setup with division of labor in a large scale production.

What is Manufacturing?

History & Development : • During early times  manufacturing was usually carried out by a single skilled artisan with assistants.

Training was by apprenticeship.

• Before the Industrial Revolution, most manufacturing occurred in rural areas, where household-based manufacturing served as a supplemental subsistence strategy to agriculture. Entrepreneurs organized a number of manufacturing households into a single enterprise through the Putting-out system (In putting-out, work is contracted by a central agent to subcontractors who complete the work in off-site facilities, either in their own homes or in workshops with multiple craftsmen).

The Industrial Revolution: The Industrial Revolution was the transition to new manufacturing processes in the period from about 1760 -1840. The transition includes hand production methods to Machines, new chemical manufacturing and iron production processes,  the increasing use of steam power and the development of machine tools and change over from usage of wood and other bio fuels to Coal.

The Major Technological Developments: The Major technological developments during the industrial revolution took place in the sectors of :

• Textile Manufacturing• Metallurgy• Mining• Steam Power• Chemicals• Machine Tools• Glass making• Paper machine &• Agriculture

Manufacturing Cycle• Clint Order – The phase where the requirement is

placed by the customer to the supplier.

• Design – Road map or a strategic approach to achieve the unique expectations by defining the various parameters such as Specification, plan, Cost, processes, Safety etc.,.

• Fabricate – The process in which all the ideas that have been designed are put into practical implication and fabricated.

• Test – The fabricated final product needs to be tested to ensure it works properly and that they perform as designed.

• Warehousing – The finished goods is finally packed and stocked at a warehouse before being dispatched

• Distribute – The Finished goods needs to be shipped to the customer through dispatching. TESTING

Manufacturing MethodsManufacturing methods can be classified into the below categories, • Mass Production

• Discreet Manufacturing. Continuous Production – High Volume / Low complexity Batch production / Assemble to order manufacturing – Low volume / High Complexity

• Process Manufacturing. Continuous production

• Repetitive Manufacturing. Batch Production Continuous production

• Assemble to order Manufacturing.• Job Production or One off Production .

Manufacturing Methods Production Techniques

Manufacturing Methods are the various ways of producing finished goods depending on the intensity of market demand & customer requirement.

Production Techniques are the methods used in manufacturing process to produce finished goods depending on the type of manufacturing

Difference Between

Discrete Manufacturing •Discrete manufacturing is the process of producing distinct items. Automobiles, Furniture's, Toys,

Mobiles & Aircraft manufacturing sectors are good examples of discrete manufacturing.

•The resulting products are easily identifiable and differ greatly from process-manufacturing where the products are undifferentiated for example oil, natural gas and salt.

•This kind of manufacturing is often characterized by individual or separate unit production.

•Units can be produced in low volume with very high complexity or high volumes of low complexity.

Low volume/high complexity

Low volume/high complexity production results in the need for an extremely flexible manufacturing system that can improve quality and time-to-market speed while cutting costs.

Low volume/high complexity

High volume/low complexity

High volume/low complexity production puts high premiums on inventory control, lead times and reducing or limiting materials costs and waste.

The processes deployed in discrete manufacturing are not continuous in nature. Each process can be individually started or stopped and can be run at varying production rates. The final product may be produced out of single or multiple inputs.

High volume/low complexity

Producing a STEEL structure will need only one type of raw material - steel. Producing a mobile phone requires many different inputs, The plastic case, LCD display, the mother board, PVC keypad, sockets, cables are made from different materials, at different places.  

Process ManufacturingProcess manufacturing is the branch of manufacturing that is associated with formulas and manufacturing

recipes, and can be contrasted with Discrete Manufacturing, which is concerned with bills of material and routing. Process manufacturing like production of paper or petroleum refining, where the end product is obtained by a continuous process or a set of continuous processes.

Simpler definition of Process manufacturing is once an output is produced by this process, it cannot be distilled back to its basic components.

For instance consider a can of soda cannot be returned to its basic components such as carbonated water, citric acid, Potassium benzoate, aspartame and other ingredients. A plastic card manufactured cannot be returned to its basic components like PVR sheets, transparent sheets.

Where as a car or computer, on the other hand, can be disassembled and its components, to a large extent can be returned to stock.

Difference Between

Discrete Manufacturing process manufacturingIt is the process of producing distinctive items through group or batch production

The end product is obtained by continuous process or a series of continuous processes

Discrete manufacturing process allows for temporary stoppage of work in one area without affecting the entire unit

continuous process manufacturing requires that entire production process be stopped.

In discrete manufacturing the manufactured component can be dissembled to a large extant and returned to stock.

Where as in process manufacturing once when the output is produced it cant be distilled back to its basic component or condition.

Examples of Discrete manufacturing are Automobile, Mobile, etc.,

Examples of Process manufacturing are Oil, Natural gas, Beverage, pharmaceuticals etc.,

Batch methods can result in the build up of significant “work in progress” or stocks (i.e. completed batches waiting for their turn to be worked on in the next operation). This increases costs as it takes up space and raises the chance of damage to stock.

The main disadvantage is that with so much machinery it is very difficult to alter the production process. This makes production inflexible and means that all products have to be very similar or standardised and cannot be tailored to individual tastes.

Repetitive ManufacturingRepetitive manufacturing is period based planning and not based on orders. Normally same products will be manufactured over longer periods of time.  Products will not change frequently. A total quantity is produced according to a certain production rate over a certain period of time. Costs are collected periodically at a product cost collector.

It involves a steady flow and simplified routing through production lines. The routing of the individual products are very similar, and also the  components are often staged at the production lines without reference to a particular order. The confirmations (back flushes) are usually executed periodically with no reference to an order (for example, all the quantities produced in one shift).

Back flushing in Repetitive Manufacturing is used to record the work progress on the production line in the system.

Back Flushing

For this purpose, a final back flush is usually carried out at the end of the production line whereby the following processes can be carried out separately:

•Posting goods receipts for finished parts•Posting goods issues for components•Reducing planned orders or production quantities•Posting production costs to the product cost collector•Updating statistics in the Logistics Information System (LIS).• such as, the goods receipt statistics or the statistics on material consumption, for

example.

Difference Between

Discrete Manufacturing Repetitive ManufacturingOrder-based production (Production in individual production orders Period-based production (Production with certain quantities per

period)

Products change frequently Products produced remain unchanged over a long periods of time

Varying sequence of work centers (complex routing) Steady flow through production (simplified routing)

Semi finished products often put into interim storage Semi finished products often directly processed without interim storage

Components are staged with reference to order Components are staged at lines periodically and anonymously

Status processing Reduced control effort (no status procedures)

Completion confirmation (Back flush) for individual operations or orders.

The confirmations (back flushes) are usually executed periodically with no reference to an order 

Order based cost controlling Period based cost controlling

Back flushing ? Back-flushing means deduction( reducing) of required quantity from Inventory on hand quantity.

In case of push supply type you have to deliver materials to shop floor and deduct quantity yourself .In case of pull system back-flushing you have to delivery materials to shop floor and need not deduct quantity yourself but system automatically deducts quantity from sub-inventory-locator on hand quantity when any assembly or an operation is completed in WIP module manufacturing process. 

Once any assembly is completed in WIP, please go to inventory module and check the sub inventory and locator quantity for the item for which assembly is completed. You will observe that on hand quantity has reduced .

Example : If total was 100 numbers and 10 numbers are pulled, by WIP assembly or operation pull, balance will be 90 numbers in the sub inventory which will be updated by system when the assembled component moves on to next stage automatically.

Assemble to Order ManufacturingAssemble to Order is a production approach where products are not built until a confirmed order for products is received.

It is one of the oldest styles of manufacturing and is the most appropriate approach used for highly customized or low volume products.

A customized YATCH made on the basis of Assemble to Order

This approach is considered good for highly configured products, e.g. Automobiles, Air-crafts, Computer servers or for products where holding inventories is very expensive, e.g. Shipbuilding (YATCH Manufacturing), and is a demand driven production approach where a product is scheduled and built in response to a confirmed order received for it from a final customer.

The main advantages of the BTO approach in environments of high product variety is the ability to supply the customer with the exact product specification required, the reduction in sales discounts and finished good inventory, as well a reduction in stock obsolescence risk.

Types of ProductionContinuous production. Batch Production.

Job Or One off production

Continuous production is a flow production method used to manufacture, produce, or process materials without interruption. Continuous production is called a continuous process or a continuous flow process because the materials, either dry bulk or fluids that are being processed are continuously in motion, undergoing chemical reactions or subject to mechanical or heat treatment.

Continuous Production

Continuous usually means operating 24 hours per day, seven days per week with infrequent maintenance shutdowns, such as semi-annual or annual. Some chemical plants can operate for more than one or two years without a shutdown. Blast furnaces can run eight to ten years without stopping.

Some common continuous processes are the following:

•Oil refining.•Chemicals.•Synthetic Fibres.•Fertilizers.•Pulp & Paper.•Blast Furnace (iron).•Metal smelting.•Power Stations.•Natural gas processing

Batch ProductionBatch production is a technique used in manufacturing, in which the object in question is created stage by stage over a series of workstations.

Batch production is most common in bakeries and in the manufacture of sports shoes, pharmaceutical ingredients, purifying water (APIs), inks, paints and adhesives.

It can reduce initial capital outlay (the cost of setting up the machines) because a single production line can be used to produce several products. As shown in the example, batch production can be useful for small businesses who cannot afford to run continuous production lines. If a retailer buys a batch of a product that does not sell, then the producer can cease production without having to sustain huge losses. Batch production is also useful for a factory that makes seasonal items, products for which it is difficult to forecast demand, a trial run for production, or products that have a high profit margin.

Job Production or One off ProductionJob production, sometimes called jobbing or one-off production, involves producing custom work, such as a one-off product for a specific customer or a small batch of work in quantities usually less than those of mass-market products.

Job production is most often associated with classical Craft production, small firms (making railings for a specific house, building/repairing a computer for a specific customer, making flower arrangements for a specific wedding etc.) but large firms use job production too. Examples include:

•Construction of bridges•Building a new factory•Designing and implementing an advertising campaign•Auditing the accounts of a large Public limited company•Installing machinery in a factory•Machining a batch of parts per a CAD drawing supplied by a

customer

Fabrication Shops and machine shops whose work is primarily of the job production type are often called job shops 

Key benefits•Can provide emergency parts or services, such as quickly making a machine part that would take a long time

to acquire otherwise.•Can provide parts or services for machinery or systems that are otherwise not available, as when the original

supplier no longer supports the product or goes out of business (orphaned).•Work is generally of a high quality.•A high level of customisation is possible to meet the customer's exact requirements.•Significant flexibility is possible, especially when compared to mass production workers can be easily

motivated due to the skilled nature of the work they are performing

Disadvantages•Higher cost of production.•Re-engineering: sometimes engineering drawings or an engineering assessment, including calculations or

specifications, needs to be made before the work can be done.•Requires the use of specialist labour (compare with the repetitive, low-skilled jobs in mass production)•slow compared to other methods (batch production and mass production)

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