1.

Total Quality Management (TQM) refers to management methods used to enhance quality and productivity in organizations, particularly businesses. TQM is a comprehensive system approach that works horizontally across an organization, involving all departments and employees and extending backward and forward to include both suppliers and clients/customers.

TQM is only one of many acronyms used to label management systems that focus on quality. Other acronyms that have been used to describe similar quality management philosophies and programs include CQI (continuous quality improvement), SQC (statistical quality control), QFD (quality function deployment), QIDW (quality in daily work), TQC (total quality control), etc. Like many of these other systems, TQM provides a framework for implementing effective quality and productivity initiatives that can increase the profitability and competitiveness of organizations.

Origins of Tqm

Although TQM techniques were adopted prior to World War II by a number of organizations, the creation of the Total Quality Management philosophy is generally attributed to Dr. W. Edwards Deming. In the late 1920s, while working as a summer employee at Western Electric Company in Chicago, he found worker motivation systems to be degrading and economically unproductive; incentives were tied directly to quantity of output, and inefficient post-production inspection systems were used to find flawed goods.

Deming teamed up in the 1930s with Walter A. Shewhart, a Bell Telephone Company statistician whose work convinced Deming that statistical control techniques could be used to supplant traditional management methods. Using Shewhart's theories, Deming devised a statistically controlled management process that provided managers with a means of determining when to intervene in an industrial process and when to leave it alone. Deming got a chance to put Shewhart's statistical-quality-control techniques, as well as his own management philosophies, to the test during World War II. Government managers found that his techniques could be easily taught to engineers and workers, and then quickly implemented in over-burdened war production plants.

One of Deming's clients, the U.S. State Department, sent him to Japan in 1947 as part of a national effort to revitalize the war-devastated Japanese economy. It was in Japan that Deming found an enthusiastic reception for his management ideas. Deming introduced his statistical process control, or statistical quality control, programs into Japan's ailing manufacturing sector. Those techniques are credited with instilling a dedication to quality and productivity in the Japanese industrial and service sectors that allowed the country to become a dominant force in the global economy by the 1980s.

While Japan's industrial sector embarked on a quality initiative during the middle 1900s, most American companies continued to produce mass quantities of goods using traditional management techniques. America prospered as war-ravaged European countries looked to the United States for manufactured goods. In addition, a domestic population boom resulted in

surging U.S. markets. But by the 1970s some American industries had come to be regarded as inferior to their Asian and European competitors. As a result of increasing economic globalization during the 1980s, made possible in part by advanced information technologies, the U.S. manufacturing sector fell prey to more competitive producers, particularly in Japan.

In response to massive market share gains achieved by Japanese companies during the late 1970s and 1980s, U.S. producers scrambled to adopt quality and productivity techniques that might restore their competitiveness. Indeed, Deming's philosophies and systems were finally recognized in the United States, and Deming himself became a highly-sought-after lecturer and author. The "Deming Management Method" became the model for many American corporations eager to improve. And Total Quality Management, the phrase applied to quality initiatives proffered by Deming and other management gurus, became a staple of American enterprise by the late 1980s. By the early 1990s, the U.S. manufacturing sector had achieved marked gains in quality and productivity.

Tqm Principles

Specifics related to the framework and implementation of TQM vary between different management professionals and TQM program facilitators, and the passage of time has inevitably brought changes in TQM emphases and language. But all TQM philosophies share common threads that emphasize quality, teamwork, and proactive philosophies of management and process improvement. As Howard Weiss and Mark Gershon observed in Production and Operations Management, "the terms quality management, quality control, and quality assurance often are used interchangeably. Regardless of the term used within any business, this function is directly responsible for the continual evaluation of the effectiveness of the total quality system." They go on to delineate the basic elements of total quality management as expounded by the American Society for Quality Control: 1) policy, planning, and administration; 2) product design and design change control; 3) control of purchased material; 4) production quality control; 5) user contact and field performance; 6) corrective action; and 7) employee selection, training, and motivation.

For his part, Deming pointed to all of these factors as cornerstones of his total quality philosophies. In his book Out of the Crisis, he contended that companies needed to create an overarching business environment that emphasized improvement of products and services over short-term financial goals. He argued that if such a philosophy was adhered to, various aspects of business—ranging from training to system improvement to manager-worker relationships—would become far more healthy and, ultimately, profitable. But while Deming was contemptuous of companies that based their business decisions on statistics that emphasized quantity over quality, he firmly believed that a well-conceived system of statistical process control could be an invaluable TQM tool. Only through the use of statistics, Deming argued, can managers know exactly what their problems are, learn how to fix them, and gauge the company's progress in achieving quality and organizational objectives.

Making Tqm Work

Joseph Jablonski, author of Implementing TQM, identified three characteristics necessary for TQM to succeed within an organization: participative management; continuous process improvement; and the utilization of teams. Participative management refers to the intimate involvement of all members of a company in the management process, thus de-emphasizing traditional top-down management methods. In other words, managers set policies and make key decisions only with the input and guidance of the subordinates that will have to implement and adhere to the directives. This technique improves upper management's grasp of operations and, more importantly, is an important motivator for workers who begin to feel like they have control and ownership of the process in which they participate.

Continuous process improvement, the second characteristic, entails the recognition of small, incremental gains toward the goal of total quality. Large gains are accomplished by small, sustainable improvements over a long term. This concept necessitates a long-term approach by managers and the willingness to invest in the present for benefits that manifest themselves in the future. A corollary of continuous improvement is that workers and management develop an appreciation for, and confidence in, TQM over a period of time.

Teamwork, the third necessary ingredient for the success of TQM, involves the organization of cross-functional teams within the company. This multidisciplinary team approach helps workers to share knowledge, identify problems and opportunities, derive a comprehensive understanding of their role in the over-all process, and align their work goals with those of the organization.

Jablonski also identified six attributes of successful TQM programs:

Customer focus (includes internal customers such as other departments and coworkers as well as external customers)

Process focus Prevention versus inspection (development of a process that incorporates quality during

production, rather than a process that attempts to achieve quality through inspection after resources have already been consumed to produce the good or service)

Employee empowerment and compensation Fact-based decision making Receptiveness to feedback.

Implementing Tqm

Jablonski offers a five-phase guideline for implementing total quality management: preparation, planning, assessment, implementation, and diversification. Each phase is designed to be executed as part of a long-term goal of continually increasing quality and productivity. Jablonski's approach is one of many that has been applied to achieve TQM, but contains the key elements commonly associated with other popular total quality systems.

Preparation—During preparation, management decides whether or not to pursue a TQM program. They undergo initial training, identify needs for outside consultants, develop a specific vision and goals, draft a corporate policy, commit the necessary resources, and communicate the goals throughout the organization.

Planning—In the planning stage, a detailed plan of implementation is drafted (including budget and schedule), the infrastructure that will support the program is established, and the resources necessary to begin the plan are earmarked and secured.

Assessment—This stage emphasizes a thorough self-assessment—with input from customers/clients—of the qualities and characteristics of individuals in the company, as well as the company as a whole.

Implementation—At this point, the organization can already begin to determine its return on its investment in TQM. It is during this phase that support personnel are chosen and trained, and managers and the work force are trained. Training entails raising workers' awareness of exactly what TQM involves and how it can help them and the company. It also explains each worker's role in the program and explains what is expected of all the workers.

Diversification—In this stage, managers utilize their TQM experiences and successes to bring groups outside the organization (suppliers, distributors, and other companies have impact the business's overall health) into the quality process. Diversification activities include training, rewarding, supporting, and partnering with groups that are embraced by the organization's TQM initiatives.

2.

JURAN THEORY

When he began his career in the 1920s the principal focus in quality management was on the quality of the end, or finished, product. The tools used were from the Bell system of acceptance sampling, inspection plans, and control charts. The ideas of Frederick Winslow Taylor dominated.

Juran is widely credited for adding the human dimension to quality management. He pushed for the education and training of managers. For Juran, human relations problems were the ones to isolate. Resistance to change—or, in his terms, cultural resistance—was the root cause of quality issues. Juran credits Margaret Mead's book Cultural Patterns and Technical Change for illuminating the core problem in reforming business quality.[9] He wrote Managerial Breakthrough, which was published in 1964, outlining the issue.

Juran's vision of quality management extended well outside the walls of the factory to encompass non-manufacturing processes, especially those that might be thought of as service related. For example, in an interview published in 1997[10] he observed:

The key issues facing managers in sales are no different than those faced by managers in other disciplines. Sales managers say they face problems such as "It takes us too long...we need to

reduce the error rate." They want to know, "How do customers perceive us?" These issues are no different than those facing managers trying to improve in other fields. The systematic approaches to improvement are identical. ... There should be no reason our familiar principles of quality and process engineering would not work in the sales process.

[edit] Juran's Trilogy

He also developed the "Juran's trilogy," an approach to cross-functional management that is composed of three managerial processes: quality planning, quality control and quality improvement.

3.

EDWARD DUMINGS

W Edwards Deming - Total Quality Management & Deming's 14 points

1900 - 1994

W Edwards Deming was an American statistician, considered the father of the modern quality movement. Edwards Deming strongly influenced Japanese industry post WWII with Statistical Process Control (SPC) and Total Quality Management (TQM), similar to Joseph Juran.

In 1982 Edwards Deming published “Out of the Crisis” identifying 14 points for management which if applied would enable Japanese manufacturing efficiencies to be realised.

The W Edwards Deming Institute awards prizes for individuals and organisations that embrace Total Quality Management and drive quality management forward.

Demings 14 Points Summarised

1. Create constancy of purpose and continual improvement – long term planning must replace short term reaction

2. Adopt the new (Japanese) philosophy – by management and workers alike.3. Do not depend on (quality) inspection – build quality into the product and process4. Choose quality suppliers over low cost suppliers – to minimise variation in raw

materials and supply.5. Improve constantly – to reduce variation in all aspects e.g. planning, production,

and service.6. Training on the job – for workers and management, to reduce variation in how job is

done.

7. Leadership not supervision – to get people to do a better job, not just meet targets.

8. Eliminate fear – encourage two-way communication, encourage employees to work in the organisation’s interest.

9. Break down internal barriers – department’s in an organisation are “internal customers” to each other and must work together.

10. Eliminate slogans (exhortations) – processes make mistakes not people. Management harassment of workers will create bad relations if no effort made to improve processes.

11. Eliminate numerical targets – management by objectives (targets) encourages low quality.

12. Remover barriers to worker satisfaction – including annual appraisals13. Encourage self improvement and education for all14. Everyone is responsible for continual improvement in quality and productivity –

particularly top management

4.

TQM is the relationship between quality and productivity. It emphasizes process improvement to improve the quality of the product or service, reducing costs, and higher productivity.

Dr. Deming, a statistician and management expert credited with guiding Japan's economic recovery following World War II, created the foundation for TQM. In 1947 he was invited to help the Japanese work on their census tracts. Two years later, he returned to Japan to teach a course on statistical control. The Japanese were quite receptive to the idea of improving quality because they wanted a larger export market.

Although Deming, along with Joseph Juran, Phillip Crosby, and Kaoru Ishikawa laid the foundations of TQM, the term was actually coined by the U.S. Navy in the early 1980s. In fact, Deming does not like the term:

The term is counter productive. My work is about a transformation in management and about the profound knowledge needed for the transformation. Total quality stops people from thinking. - W. Edwards Deming (quoted in Senge, 1992)By 1980, American corporations were in a near panic as the Japanese were selling products in the United States for less than American companies could produce them. At the time, NBC aired a special television report, "If Japan Can, Why Can't We?" that explored reasons why the Americans were not competitive, such as: low labor costs in Japan, burdensome government regulation, conflict between labor and management, and the Japanese work ethic.

However, whenever a Japanese was asked why they were so productive, they would say that Edwards Deming taught them to produce quality goods. However, when Americans were asked about Edwards Deming, they did not know who he was, even though he was treated like a god in Japan. Shortly after the program aired, Deming was besieged by calls from corporations across the country asking him for help.

Joseph Juran followed Deming to Japan where his name is just as illustrious as that of Deming. While Deming centered upon statistical tools, Juran centers upon the role of employees in quality

management. In addition Juran published The Quality Control Handbook in 1950 which became the standard reference book on quality world-wide.

Another of the TQM gurus is Phillip Crosby, who developed a framework for Total Quality Management. His focus is zero defects, or get it right the first time. Crosby defines quality as conformance to the requirements which the company itself has established for its products based directly on its customers' needs.

The fourth guru associated with TQM is Kaoru Ishikawa who initiated Company-wide Quality Control that started in Japan during the period 1955-1960, following the visits of Deming and Juran. Ishikawa sees the CWQC as implying that quality does not only mean the quality of product, but also of after sales service, quality of management, the company itself and the human life. Ishikawa's biggest contributions are in simplifying statistical techniques for quality control and inventing quality circles. In addition, he created the cause-and-effect diagram (the Ishikawa diagram or the fishbone diagram).

5. QUALITY ASSURANCE

Quality assurance, or QA for short, refers to a program for the systematic monitoring and evaluation of the various aspects of a project, service, or facility to ensure that standards of quality are being met.

It is important to realize also that quality is determined by the program sponsor. QA cannot absolutely guarantee the production of quality products, unfortunately, but makes this more likely.

Two key principles characterise QA: "fit for purpose" (the product should be suitable for the intended purpose) and "right first time" (mistakes should be eliminated). QA includes regulation of the quality of raw materials, assemblies, products and components; services related to production; and management, production and inspection processes.

It is important to realize also that quality is determined by the intended users, clients or customers, not by society in general: it is not the same as 'expensive' or 'high quality'. Even goods with low prices can be considered quality items if they meet a market need.

QUALITY CONTROL

The company-wide quality approach places an emphasis on three aspects :

1. Elements such as controls, job management, defined and well managed processes[1][2], performance and integrity criteria, and identification of records

2. Competence, such as knowledge, skills, experience, and qualifications3. Soft elements, such as personnel integrity, confidence, organizational culture, motivation,

team spirit, and quality relationships.

The quality of the outputs is at risk if any of these three aspects is deficient in any way.

Total quality control

Total Quality Control is the most important inspection control of all in cases where, despite statistical quality control techniques or quality improvements implemented, sales decrease.

If the original specification does not reflect the correct quality requirements, quality cannot be inspected or manufactured into the product.

For instance, the parameters for a pressure vessel should include not only the material and dimensions, but also operating, environmental, safety, reliability and maintainability requirements.

6. QUALIY STANDARD/ BUISNESS EXCELENCE MODEL

The need for a model Regardless of sector, size, structure or maturity, organisations need to establish an appropriate management system to be successful. The Excellence Model is a practical tool to help organisations do this by measuring where they are on the path to Excellence; helping them understand the gaps; and then stimulating solutions. The British Quality Foundation (BQF), with the European Foundation for Quality Management (EFQM), is committed to researching and updating the Model with the inputs of tested good practices from thousands of organisations both within and outside of Europe. In this way they ensure the Model remains dynamic and in line with current management thinking.

Overview of the Excellence Model The Model is an over-arching, non-prescriptive framework based on nine criteria. Five of these are 'Enablers' and four are 'Results'. The 'Enabler' criteria cover what an organisation does. The 'Results' criteria cover what an organisation achieves. 'Results' are caused by 'Enablers'.

The Model, which recognises there are many approaches to achieving sustainable excellence in all aspects of performance, is based on the premise that:

Excellent results with respect to Performance, Customers, People and Society are achieved through Leadership driving Policy and Strategy, that is delivered through People Partnerships and Resources, and Processes.

The arrows emphasise the dynamic nature of the model. They show innovation and learning helping to improve enablers that in turn lead to improved results.

Model structure The Model's nine boxes, shown above, represent the criteria against which to assess an organisation's progress towards excellence. Each of the nine criteria has a definition, which explains the high level meaning of that criterion.

To develop the high level meaning further each criterion is supported by a number of sub-criteria. Sub-criteria pose a number of questions that should be considered in the course of an assessment.

Below each sub-criterion are lists of possible areas to address. The areas to address are not mandatory nor are they exhaustive lists but are intended to further exemplify the meaning of the sub-criterion.

EnablersLeadershipPolicy & StrategyPeoplePartnerships & ResourcesProcesses

ResultsCustomer ResultsPeople ResultsSociety ResultsKey Performance Results

The Fundamental Concepts of Excellence The EFOM Model is a non-prescriptive framework that recognises there are many approaches to achieving sustainable excellence. Within this non-prescriptive approach there are some Fundamental Concepts which underpin the EFQM Model. These are expressed below.

There is no significance intended in the order of the concepts. The list is not meant to be

exhaustive and they will change as excellent organisations develop and improve.

Results OrientationExcellence is achieving results that delight all the organisation's stakeholders.

Customer FocusExcellence is creating sustainable customer value.

Leadership & Constancy of PurposeExcellence is visionary and inspirational leadership, coupled with constancy of purpose.

Management by Processes & FactsExcellence is managing the organisation through a set of interdependent and interrelated systems, processes and facts.

People Development & InvolvementExcellence is maximising the contribution of employees through their development and involvement.

Continuous Learning, Innovation & ImprovementExcellence is challenging the status quo and effecting change by using learning to create innovation and improvement opportunities.

Partnership DevelopmentExcellence is developing and maintaining value-adding partnerships.

Corporate Social ResponsibilityExcellence is exceeding the minimum regulatory framework in which the organisation operates and to strive to understand and respond to the expectations of their stakeholders in society.

RADARAt the heart of the self assessment process lies the logic known as RADAR which has the following elements: Results, Approach, Deployment, Assessment and Review.

The logic of RADAR® states that an organisation should:

• Determine the Results it is aiming for.

• Implement an integrated set of sound Approaches to deliver the required results.

• Deploy the approaches systematically.

• Assess and Review the effectiveness of the approaches.

7. AUDITING OF QUALITY PROCESS AND SERVICES

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Types of Quality Assurance Audits

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Quality assurance audit is performed in order to ensure that the systems are in place and being followed religiously to provide good quality to the customers. It also highlights the need for any improvement in the systems in order to consistently deliver good quality products or services. The audits are also performed to make sure that the organization is following the legal and regulatory requirements. Some audits are conducted by internal auditors whereas some are performed by external ones.

Various Quality Assurance Audit Types Are

System Audit

The organization has various systems which when put together make a whole system. A system audit is an audit performed on any of these systems. Any non-conformity during a system audit is critical, since if the system itself is wrong, the output is likely to be wrong.

Product or Service Audit

The product or service audit is performed on the product or service to find out if the product or service meets the requirements of the customers and the standards set by the organization. There are various stages at which this can be performed. It could be during the process of product manufacturing, after the product has been manufactured, or even after the product is packed and ready to be delivered to the customer. The nonconformities found during this quality assurance audit are taken very seriously, since all these nonconformities are equivalent to customer complaints.

Department Audit

As the name suggests, the department audit is performed with a focus on a given department. The scope of the audit covers all the activities performed, all the procedures followed and all the systems available in the department. This audit highlights the areas for improvement in that department.

Process Audit

Various processes are critical for the smooth running of an organization. Actually speaking, all the activities from order inquiry to delivery of products follow a defined process in any organization. Hence, an audit of such processes is performed to identify the areas for improvement. Process audit also covers the audit of some special manufacturing processes that are critical for the quality of the end product. These processes may be in-house or at the suppliers place, the one to whom that process has been outsourced to.

Conformance Audit

The external parties normally perform this QA audit. It is a form of third party audit where the auditing party evaluates if the organization does meet the requirements as are supposed to by the systems. This could also be for any kind of system certifications that organizations wish to apply for. The certificate-awarding agency also conducts the conformance audit periodically to make sure that the organization is meeting the certification requirements.

Compliance Audit

Compliance audit is performed by regulatory agencies to confirm if the organization is meeting the legal and regulatory requirements. In case of any non-conformity, a re-audit may be required. The purpose of the re-audit is to ensure the effectiveness of the corrective actions taken.

The output of the audit is an audit report that is circulated to all the concerned people. The purpose of any type of QA audit is not to find mistakes, but to find the areas for improvements. If it is taken by the auditor and the audited party in this spirit, the organization can be sure that it is on the path to improvement and will be able to consistently meet all customers, system, legal or regulatory requirements.

8. COST OF QUALITY

Overview

Cost of Quality ("COQ")  is a measurement used for assessing the waste or losses from some defined process (eg. machine, production line, plant, department, company, etc.).

Recognizing the power and universal applicability of Cost of Quality ("COQ"), PQA has developed numerous proprietary Cost of Quality ("COQ") systems for ensuring the effectiveness of Cost of Quality ("COQ") implementations.

The Cost of Quality ("COQ") measurement can track changes over time for one particular process, or be used as a benchmark for comparison of two or more different processes (eg. two machines, different production lines, sister plants, two competitor companies, etc.). 

Usually, Cost of Quality ("COQ") is measured in currency (eg. $), requiring all losses and wastes to be converted to their liquidated cost equivalent (ie. man-hrs lost or spent are converted to $ by multiplying by the hourly rate, $/hr).

Most COQ systems are defined by use of 4 categories of costs:

COQ Category

Typical Descriptions (may vary between different Organizations)

Examples

InternalCosts associated with internal losses (ie. within the process being analyzed)

off-cuts, equipment breakdowns, spills, scrap, yield, productivity

External

Costs external  the process being analyzed (ie. occur outside, not within).  These costs are usually discovered by, or affect third parties (eg. customers).  Some External costs may have originated from within, or been caused, created by, or made worse by  the process being analyzed.  They are defined as External because of where they were discovered, or who is primarily or initially affected.

customer complaints, latent defects found by the customer, warranty

Preventive

Costs associated with the prevention of future losses:   (eg. unplanned or undesired problems, losses, lost opportunities, breakdowns, work stoppages, waste, etc.)

planning, mistake-proofing, scheduled maintenance, quality assurance

AssessmentCosts associated with measurement and assessment of the process.

KPI's, inspection, quality check, dock audits, third party audits, measuring devices, reporting systems, data collection systems, forms

9. HISTOGRAM AND ITS USES

Histogram Plots

Documentation 

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Origin's histogram plot graphically summarizes the distribution of a single variable dataset, allowing you see its:

center (i.e., the location), spread (i.e., the scale) of the data, skewness of the data, presence of outliers, and presence of multiple modes in the data.

These features provide strong indications of the proper distributional model for the data.

Histogram Graph Options Stacked Histogram Example

Origin's histogram chart can be created from 2D or 3D (matrix) data. When matrix data is used as input, the whole matrix is viewed as a single variable dataset.

To obtain a histogram, the range of the input data is splitted into equal-sized bins (automatically or by user specification). Then for each bin, the number of points from the dataset that fall into each bin are counted. The result is a plot of Frequency (i.e. counts for each bin) on the vertical axis vs. response variable on the horizontal axis.

In addition to the option of specifying the bin size, the user has the option of specifying the bin minimum and bin maximum.

A Curve overlay option is provided as well. Choose from Normal, Lognormal, Poisson, Exponential, Laplace, or Lorentz. Or, use the "Bin" worksheet and fit the data to any model you desire using Origin's Nonlinear Fitting capabilities.

  Example plots from our Graph Gallery

[click on the image to see original graph]

A Stacked Histograms plot template is also provided (see figure), allowing you to view the distribution for one or more variables or one or more instances of the same variable in one convenient display.

Histogram Uses

The histogram can be used to answer the following questions:

What kind of population distribution do the data come from, or what is the most common system response?

What distribution (center, variation and shape) does the data have? Are the data symmetric or skewed? Are there outliers in the data

Basic Data Plot Properties

All of the basic data plot properties of a Column/Bar plot can be updated for Origin's Histogram chart. This includes:

Border Properties: style, width, and color Fill Properties: color, pattern Pattern Properties: border style, width, and color; pattern width and color Spacing: between each column/bar

Histograms

A histogram is a specialized type of bar chart. Individual data points are grouped together in classes, so that you can get an idea of how frequently data in each class occur in the data set.

High bars indicate more points in a class, and low bars indicate less points. In the histogram show above, the peak is in the 40-49 class, where there are four points.

The strength of a histogram is that it provides an easy-to-read picture of the location and variation in a data set. There are, however, two weaknesses of histograms that you should bear in mind:

The first is that histograms can be manipulated to show different pictures. If too few or too many bars are used, the histogram can be misleading. This is an area which requires some judgment, and perhaps some experimentation, based on the analyst's experience.

Histograms can also obscure the time differences among data sets. For example, if you looked at data for #births/day in the United States in 1996, you would miss any seasonal variations, e.g. peaks around the times of full moons. Likewise, in quality control, a histogram of a process run tells only one part of a long story. There is a need to keep reviewing the histograms and control charts for consecutive process runs over an extended time to gain useful knowledge about a process.

Histogram statistics:

For histograms, the following statistics are calculated:

Mean The average of all the values.

Minimum The smallest value.

Maximum The biggest value.

Std Dev An expression of how widely spread the values are around the mean.

Class Width The x-axis distance between the left and right edges of each bar in the histogram.

Number of Classes

The number of bars (including zero height bars) in the histograms.

Skewness Is the histogram symmetrical? If so, Skewness is zero. If the left hand tail is longer, skewness will be negative. If the right hand tail is longer, skewness will be positive. Where skewness exists, process capability indices are suspect. For process improvement, a good rule of thumb is to look at the long tail of your distribution; that is usually where quality problems lie.

Kurtosis Kurtosis is a measure of the pointiness of a distribution. The standard normal curve has a kurtosis of zero. The Matterhorn, has negative kurtosis,

while a flatter curve would have positive kurtosis. Positive kurtosis is usually more of a problem for quality control, since, with "big" tails, the process may well be wider than the spec limits.

Specification Limits and Batch Performance

Where relevant, you should display specification limits on your histograms. The specifications include a target value, an upper limit and a lower limit. For example, if Michael Jordan is shooting a basketball at a hoop, his target is the middle of the hoop. His spec limits are those points in the circle of the hoop that will just allow the ball to bounce through the basket. If the shot is outside spec limits, the ball doesn't go in.

When you overlay specification limits on a histogram, you can estimate how many items are being produced which do not meet specifications. This gives you an idea of batch performance, that is, of how the process performed during the period that you collected data. PathMaker calculates the actual percentage of items in the sample that fall outside specification limits.

When you have added target, upper and lower limit lines, you can examine your histogram to see how your process is performing.

If the histogram shows that your process is wider than the specification limits, then it is not presently capable of meeting your specifications. This means the variation of the process should be reduced.

Also, if the process is not centered on the target value, it may need to be adjusted so that it can, on average, hit the target value. Sometimes, the distribution of a process could fit between the specification limits if it was centered, but spreads across one of the limits because it is not centered. Again, the process needs to be adjusted so that it can hit the target value most often.

Center of a Distribution

Processes have a target value, the value that the process should be producing, where most output of the process should fall. The center of the distribution in a histogram should, in most cases, fall

on or near this target value. If it does not, the process will often need to be adjusted so that the center will hit the target value.

Spread of a Distribution

The spread, or width of a process is the distance between the minimum and maximum measured values. If the spread of the distribution is narrower than the specification limits, it is an indication of small variability in the process. This is almost always the goal, since consistency is important in most processes. If the distribution is wider than the specification limits the process has too much variability. The process is generating products that do not conform to specifications, i.e. junk.

Shape: Skewness and Kurtosis

A "normal" distribution of variation results in a specific bell-shaped curve, with the highest point in the middle and smoothly curving symmetrical slopes on both sides of center. The characteristics of the standard normal distribution are tabulated in most statistical reference works, allowing the relatively easy estimation of areas under the curve at any point.

Many distributions are non-normal. They may be skewed, or they may be flatter or more sharply peaked than the normal distribution.

A "skewed" distribution is one that is not symmetrical, but rather has a long tail in one direction. If the tail extends to the right, the curve is said to be right-skewed, or positively skewed. If the tail extends to the left, it is negatively skewed. PathMaker calculates the skewness of a histogram, and displays it with the other statistics. Where skewness is present, attention should usually be focused on the tail, which could extend beyond the process specification limits, and where much of the potential for improvement generally lies.

Kurtosis is also a measure of the length of the tails of a distribution. For example, a symmetrical distribution with positive kurtosis indicates a greater than normal proportion of product in the tails. Negative kurtosis indicates shorter tails than a normal distribution would have. Again, PathMaker calculates the kurtosis of histograms.

Taken together, the values for process center, spread, skewness and kurtosis can tell you a great deal about your process. However, unless you have a solid statistics background, you will probably learn more from looking at the histogram itself than from looking at the statistics. Just remember that, where there is data in the tails near a specification limit, chances are that some non-conforming product is being made. If your process is actually making 5 bad parts in every thousand, and you are sampling 20 in every thousand, it will take some time before you find any out-of-spec parts. There are three things you should do:

1. keep tracking data2. get help in fitting a curve to your distribution3. make sure your sampling plan is efficient.

PathMaker can help with the first, but not (yet) with the other two.

Distributions you may encounter

The standard normal distribution, with its zero skewness and zero kurtosis.

A skewed distribution, with one tail longer than the other.

A double-peaked curve often means that the data actually reflects two distinct processes with different centers. You will need to distinguish between the two processes to get a clear view of what is really happening in either individual process.

A truncated curve, with the peak at or near the edge while trailing gently off to the other side, often means that part of the distribution has been removed through screening, 100% inspection, or review. These efforts are usually costly and make good candidates for improvement efforts.

A plateau-like curve often means that the process is ill-defined to those doing the work, which leaves everyone on their own. Since everyone handles the process differently, there are many different measurements with none standing out. The solution here is to clearly define an efficient process.

Outliers in a histogram – bars that are removed from the others by at least the width of one bar – sometimes indicate that perhaps a separate process is included, but one that doesn't happen all the time. It may also indicate that special causes of variation are present in the process and should be investigated, though if the process is in control before the histogram is made as it should be, this latter option is unlikely.

10. ISO AND ITS SIGNIFICANCE

About ISO

ISO (International Organization for Standardization) is the world's largest developer and publisher of International Standards.

ISO is a network of the national standards institutes of 159 countries, one member per country, with a Central Secretariat in Geneva, Switzerland, that coordinates the system.

ISO is a non-governmental organization that forms a bridge between the public and private sectors. On the one hand, many of its member institutes are part of the governmental structure of their countries, or are mandated by their government. On the other hand, other members have their roots uniquely in the private sector, having been set up by national partnerships of industry associations.

Therefore, ISO enables a consensus to be reached on solutions that meet both the requirements of business and the broader needs of society.

Discover ISO

ISO's name

Because "International Organization for Standardization" would have different acronyms in different languages ("IOS" in English, "OIN" in French for Organisation internationale de normalisation), its founders decided to give it also a short, all-purpose name. They chose "ISO", derived from the Greek isos, meaning "equal". Whatever the country, whatever the language, the short form of the organization's name is always ISO.

Why standards matter

Standards make an enormous and positive contribution to most aspects of our lives.

Standards ensure desirable characteristics of products and services such as quality, environmental friendliness, safety, reliability, efficiency and interchangeability - and at an economical cost.

When products and services meet our expectations, we tend to take this for granted and be unaware of the role of standards. However, when standards are absent, we soon notice. We soon care when products turn out to be of poor quality, do not fit, are incompatible with equipment that we already have, are unreliable or dangerous.

When products, systems, machinery and devices work well and safely, it is often because they meet standards. And the organization responsible for many thousands of the standards which benefit the world is ISO.

When standards are absent, we soon notice.

What standards do

ISO standards:

make the development, manufacturing and supply of products and services more efficient, safer and cleaner

facilitate trade between countries and make it fairer provide governments with a technical base for health, safety and environmental

legislation, and conformity assessment share technological advances and good management practice disseminate innovation safeguard consumers, and users in general, of products and services make life simpler by providing solutions to common problems

Who standards benefit

ISO standards provide technological, economic and societal benefits.

For businesses, the widespread adoption of International Standards means that suppliers can develop and offer products and services meeting specifications that have wide international acceptance in their sectors. Therefore, businesses using International Standards can compete on many more markets around the world.

For innovators of new technologies, International Standards on aspects like terminology, compatibility and safety speed up the dissemination of innovations and their development into manufacturable and marketable products.

For customers, the worldwide compatibility of technology which is achieved when products and services are based on International Standards gives them a broad choice of offers. They also benefit from the effects of competition among suppliers.

For governments, International Standards provide the technological and scientific bases underpinning health, safety and environmental legislation.

For trade officials, International Standards create "a level playing field" for all competitors on those markets. The existence of divergent national or regional standards can create technical barriers to trade. International Standards are the technical means by which political trade agreements can be put into practice.

For developing countries, International Standards that represent an international consensus on the state of the art are an important source of technological know-how. By defining the characteristics that products and services will be expected to meet on export markets, International Standards give developing countries a basis for making the right decisions when investing their scarce resources and thus avoid squandering them.

For consumers, conformity of products and services to International Standards provides assurance about their quality, safety and reliability.

For everyone, International Standards contribute to the quality of life in general by ensuring that the transport, machinery and tools we use are safe.

For the planet we inhabit, International Standards on air, water and soil quality, on emissions of gases and radiation and environmental aspects of products can contribute to efforts to preserve the environment.  

The ISO brand

Democratic

Every full member of ISO has the right to take part in the development of any standard which it judges to be important to its country's economy. No matter what the size or strength of that economy, each participating member in ISO has one vote. Each country is on an equal footing to

influence the direction of ISO's work at the strategic level, as well as the technical content of its individual standards.

Voluntary

ISO standards are voluntary. As a non-governmental organization, ISO has no legal authority to enforce the implementation of its standards. ISO does not regulate or legislate. However, countries may decide to adopt ISO standards - mainly those concerned with health, safety or the environment - as regulations or refer to them in legislation, for which they provide the technical basis. In addition, although ISO standards are voluntary, they may become a market requirement, as has happened in the case of ISO 9001 quality management systems, or of dimensions of freight containers and bank cards.

ISO itself does not regulate or legislate.

Market-driven

ISO only develops standards for which there is a market requirement. The work is mainly carried out by experts from the industrial, technical and business sectors which have asked for the standards, and which subsequently put them to use.

Consensus

ISO standards are based on international consensus among the experts in the field. Consensus, like technology, evolves and ISO takes account both of evolving technology and of evolving interests by requiring a periodic review of its standards at least every five years to decide whether they should be maintained, updated or withdrawn. In this way, ISO standards retain their position as the state of the art.

Globally relevant

ISO standards are technical agreements which provide the framework for compatible technology worldwide. They are designed to be globally relevant - useful everywhere in the world.

ISO standards are useful everywhere in the world.

How to recognize an ISO standard

In paper form, an ISO standard is published in A4 format - which is itself one of the ISO standard paper sizes. It may be anywhere between a four-page document and one several hundred pages' long. ISO standards are also available as electronic downloads and many are available as part of a collection on CD or in handbook. An ISO standard carries the ISO logo and the designation, "International Standard".

The scope of ISO's work

ISO has more than 18   000 International Standards and other types of normative documents in its current portfolio. ISO's work programme ranges from standards for traditional activities, such as agriculture and construction, through mechanical engineering, manufacturing and distribution, to transport, medical devices, information and communication technologies, and to standards for good management practice and for services.

Examples of the benefits standards provide

Standardization of screw threads helps to keep chairs, children's bicycles and aircraft together and solves the repair and maintenance problems caused by a lack of standardization that were once a major headache for manufacturers and product users.

Standards establishing an international consensus on terminology make technology transfer easier and safer. They are an important stage in the advancement of new technologies and dissemination of innovation.

Without the standardized dimensions of freight containers, international trade would be slower and more expensive.

Without the standardization of telephone and banking cards, life would be more complicated.

A lack of standardization may even affect the quality of life itself: for the disabled, for example, when they are barred access to consumer products, public transport and buildings because the dimensions of wheel-chairs and entrances are not standardized.

Standardized symbols provide danger warnings and information across linguistic frontiers.

Consensus on grades of various materials gives a common reference for suppliers and clients in business dealings.

Agreement on a sufficient number of variations of a product to meet most current applications allows economies of scale with cost benefits for both producers and consumers. An example is the standardization of paper sizes.

Standardization of performance or safety requirements of diverse equipment makes sure that users' needs are met while allowing individual manufacturers the freedom to design their own solution on how to meet those needs.

Standardized computer protocols allow products from different vendors to "talk" to each other.

Standardized documents speed up the transit of goods, or identify sensitive or dangerous cargoes that may be handled by people speaking different languages.

Standardization of connections and interfaces of all types ensures the compatibility of equipment of diverse origins and the interoperability of different technologies.

Agreement on test methods allows meaningful comparisons of products, or plays an important part in controlling pollution - whether by noise, vibration or emissions.

Safety standards for machinery protect people at work, at play, at sea... and at the dentist's.

Without the international agreement contained in ISO standards on metric quantities and units, shopping and trade would be haphazard, science would be unscientific and technological development would be handicapped.

For more examples of the many areas of life and work where ISO standards provide technical, economic and social benefits, visit The ISO Café.

What's different about ISO 9001 and ISO 14001

The vast majority of ISO standards are highly specific to a particular product, material, or process. However, ISO 9001 (quality) and ISO 14001 (environment) are "generic management system standards". "Generic" means that the same standard can be applied to any organization, large or small, whatever its product or service, in any sector of activity, and whether it is a business enterprise, a public administration, or a government department. ISO 9001 contains a generic set of requirements for implementing a quality management system and ISO 14001 for an environmental management system.

Generic standards can be applied to any organization.

Why conformity assessment is important

"Conformity assessment" means checking that products, materials, services, systems, processes or people measure up to the specifications of a relevant standard or specification. Today, many products require testing for conformity with specifications or compliance with safety, or other regulations before they can be put on many markets. ISO guides and standards for conformity assessment represent an international consensus on best practice. Their use contributes to the consistency of conformity assessment worldwide and so facilitates trade.

See ISO's Conformity assessment pages for more detailed information.

What "international standardization" means

When the large majority of products or services in a particular business or industry sector conform to International Standards, a state of industry-wide standardization exists. The economic stakeholders concerned agree on specifications and criteria to be applied consistently in the classification of materials, in the manufacture and supply of products, in testing and analysis, in terminology and in the provision of services. In this way, International Standards provide a reference framework, or a common technological language, between suppliers and their customers. This facilitates trade and the transfer of technology.