Quality Assurance & Quality Controldoc
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Quality assurance From Wikipedia, the free encyclopedia
(Redirected from Quality Assurance) Jump to: navigation, search The introduction to this article provides insufficient context for those unfamiliar with the subject. Please help improve the article with a good introductory style.
Quality assurance, or QA for short, refers to planned and systematic processes that provide confidence of a product's or service's effectiveness. More accurately, quality assurance is a standard for meeting customer requirements. It documents how a company will meet the requirements of a client or customer in a systematic, reliable fashion. It shows a companies commitment to delivering quality products and services to the purchaser. It does not however guarantee a quality product nor should the quality assurance logo or stamp of approval be placed on the product as it is the company and not the product or service that is quality assured.
Contents [hide]
• • • • •
1 History o 1.1 Early efforts to control the quality of production o 1.2 Wartime production o 1.3 Postwar 2 Quality assurance 3 Quality control activities o 3.1 Peer reviews o 3.2 Failure testing o 3.3 Statistical control o 3.4 Total quality control o 3.5 ISO 17025 4 Company quality 5 Using Contractors and/or consultants 6 Academic resources 7 See also 8 References
•
9 External links
•
• •
[edit] History
[edit] Early efforts to control the quality of production When the first specialized craftsmen arose manufacturing tools for others, the principle of quality was simple: "let the buyer beware" (caveat emptor). Early civil engineering projects needed to be built from specifications. For example in order to ensure the four sides of the base of the Great Pyramid of Giza would be perpendicular to within 3.5 arcseconds. During the Middle Ages, guilds took the responsibility of quality control upon themselves. Royal governments purchasing material were interested in quality control as customers. For this reason , King John of England appointed a certain William Wrotham to report about the construction and repair of ships. Some centuries later, but also in England, Samuel Pepys, Secretary to the Admiralty, appointed multiple such overseers. Prior to the extensive division of labor and mechanization resulting from the Industrial Revolution, it was possible for workers to control the quality of their own products. Working conditions then were more conducive to professional pride. The Industrial Revolution led to a system in which large groups of people performing a similar type of work were grouped together under the supervision of a foreman who was appointed to control the quality of work manufactured.
[edit] Wartime production During World War I, the manufacturing process became more complex, and the introduction of large numbers of workers being supervised by a foreman designated to ensure the quality of the work, which was being produced. This period also introduced mass production and piecework, which created problems as workmen could now earn more money by the production of extra products, which in turn led to bad workmanship being passed on to the assembly lines. Due to the large amount of bad workmanship being produced, the first full time inspectors were introduced into the large-scale modern factory. These full time inspectors were the real beginning of inspection quality control, and this was the beginning the large inspection organizations of the 1920s and 1930s, which were separately organised from production and big enough to be headed by superintendents. The systematic approach to quality started in industrial manufacture during the 1930s, mostly in the USA, when some attention was given to the cost of scrap and rework. With the impact of mass production, which was required during the Second World War, it became necessary to introduce a more appropriate form of quality control which can be identified as Statistical Quality Control, or SQC. Some of the initial work for SQC is
credited to Walter A. Shewhart of Bell Labs, starting with his famous one-page memorandum of 1924. This system came about with the realization that quality cannot be fully inspected into an important batch of items. By extending the inspection phase and making inspection organizations more efficient, it provides inspectors with control tools such as sampling and control charts. SQC had a significant contribution in that it provided a sampling inspection system where 100 per cent inspection was not practicable. This type of inspection however did lead to a lack of attention to the engineering activities for producinq quality. For example, if you have a basic sampling scheme with an acceptance level of 4%, what happens is you have a ratio of 96% products released onto the market with 4% defective items – this obviously is a fair risk if you are ensured that unfortunate buyers will not complain.
[edit] Postwar After World War II, the United States continued to apply the concepts of inspection and sampling to remove defective product from production lines. However, there were many individuals trying to lead U.S. industries towards a more comprehensive approach to quality. Excluding the U.S., many countries' manufacturing capabilities were destroyed during the war. This placed American business in a position where advances in the collaborative approaches to quality were essentially ignored. After World War II, the U.S. sent General Douglas MacArthur to oversee the re-building of Japan. During this time, General MacArthur involved two key individuals in the development of modern quality concepts: W. Edwards Deming and Joseph Juran. Both individuals promoted the collaborative concepts of quality to Japanese business and technical groups, and these groups utilized these concepts in the redevelopment of the Japanese economy.
[edit] Quality assurance Unlike Quality Control, Quality Assurance is an activity that is derived from business objectives. As Quality Control is a production activity, Quality Assurance is an on-going activity that serves as the eyes of upper-management. If a process activity does not respect the previously agreed-upon steps, then QA will report this to ensure corrective action. Quality assurance activities are executed on all development processes to help maintain an expected level of effectiveness.
[edit] Quality control activities
Quality control applies to all forms of products and services as a verification (testing) activity. This introduced the rules: "fit for purpose" and "do it right the first time". It includes the regulation of the quality of raw materials, assemblies, products and components; services related to production; and management, production, and inspection processes. The purpose is to detect defects at the earliest stages of development. Quality assurance is then applied to these processes to maintain the effectiveness of defect removal. One of the most widely used paradigms for Test management is the PDCA (Plan-DoCheck-Act) approach, also known as the Shewhart cycle.
[edit] Peer reviews Peer reviews are an integral part of Quality control activities. They are the most effective means of reducing defects during the development lifecycle.
[edit] Failure testing A valuable process to perform on a whole consumer product is failure testing, the operation of a product until it fails, often under stresses such as increasing vibration, temperature and humidity. This exposes many unanticipated weaknesses in a product, and the data is used to drive engineering and manufacturing process improvements. Often quite simple changes can dramatically improve product service, such as changing to mould-resistant paint or adding lock-washer placement to the training for new assembly personnel.
[edit] Statistical control Many organizations use statistical process control to bring the organization to Six Sigma levels of quality, in other words, so that the likelihood of an unexpected failure is confined to six standard deviations on the normal distribution. This probability is less than four one-millionths. Items controlled often include clerical tasks such as order-entry as well as conventional manufacturing tasks. Traditional statistical process controls in manufacturing operations usually proceed by randomly sampling and testing a fraction of the output. Variances of critical tolerances are continuously tracked, and manufacturing processes are corrected before bad parts can be produced. It's very necessary to monitor phase wise activities so that any variance is in any phase project can take action and save project deliverables of next phase from delayed and achieve customer satisfaction.
[edit] Total quality control
Deep Analysis of quality assurance practices and premisses used about them is the most necessary inspection control of all in cases where, despite statistical quality control techniques or quality improvements implemented, sales decrease. The major problem which leads to a decrease in sales was that the specifications did not include the most important factor, “What the specifications have to state in order to satisfy the customer requirements?”. The major characteristics, ignored during the search to improve manufacture and overall business performance were: • • • •
Reliability Maintainability Safety Strength
As the most important factor had been ignored, a few refinements had to be introduced: 1. Marketing had to carry out their work properly and define the customer’s specifications. 2. Specifications had to be defined to conform to these requirements. 3. Conformance to specifications i.e. drawings, standards and other relevant documents, were introduced during manufacturing, planning and control. 4. Management had to confirm all operators are equal to the work imposed on them and holidays, celebrations and disputes did not affect any of the quality levels. 5. Inspections and tests were carried out, and all components and materials, bought in or otherwise, conformed to the specifications, and the measuring equipment was accurate, this is the responsibility of the QA/QC department. 6. Any complaints received from the customers were satisfactorily dealt with in a timely manner. 7. Feedback from the user/customer is used to review designs. 8. Consistent data recording and assessment and documentation integrity. 9. Product and/or process change management and notification. If the original specification does not reflect the correct quality requirements, quality cannot be implemented into the product. For instance, all parameters for a pressure vessel should include not only the material and dimensions but operating, environmental, safety, reliability and maintainability requirements. To conclude, the above forms the basis from which the philosophy of Quality has evolved, and the achievement of quality or the “fitness-for-purpose” is “Quality Awareness” throughout the company.
The following are examples of best practice models that enhance the development process:
[edit] ISO 17025 ISO 17025 is an international standard that specifies the general requirements for the competence to carry out tests and or calibrations. There are 15 management requirements and 10 technical requirements. These requirements outline what a laboratory must do to become accredited. Management system refers to the organization's structure for managing its processes or activities that transform inputs of resources into a product or service which meets the organization's objectives, such as satisfying the customer's quality requirements, complying with regulations, or meeting environmental objectives. The CMMI (Capability Maturity Model Integration) model is widely used to implement Quality Assurance (PPQA) in an organization. The CMMI maturity levels can be divided in to 5 steps, which a company can achieve by performing specific activities within the organization.
[edit] Company quality During the 1980s, the concept of “company quality” with the focus on management and people came to the fore. It was realized that, if all departments approached quality with an open mind, success was possible if the management led the quality improvement process. The company-wide quality approach places an emphasis on four aspects :1. Elements such as controls, job management, adequate processes, performance and integrity criteria and identification of records 2. Competence such as knowledge, skills, experience, qualifications 3. Soft elements, such as personnel integrity, confidence, organizational culture, motivation, team spirit and quality relationships. 4. Infrastructure (as it enhances or limits functionality) The quality of the outputs is at risk if any of these aspects is deficient in any way. The approach to quality management given here is therefore not limited to the manufacturing theatre only but can be applied to any business or non-business activity: • • • • • • •
Design work Administrative services Consulting Banking Insurance Computer software Retailing
• • •
Transportation open source development education
It comprises a quality improvement process, which is generic in the sense it can be applied to any of these activities and it establishes a behaviour pattern, which supports the achievement of quality. This in turn is supported by quality management practices which can include a number of business systems and which are usually specific to the activities of the business unit concerned. In manufacturing and construction activities, these business practices can be equated to the models for quality assurance defined by the International Standards contained in the ISO 9000 series and the specified Specifications for quality systems. Still, in the system of Company Quality, the work being carried out was shop floor inspection which did not reveal the major quality problems. This led to quality assurance or total quality control, which has come into being recently.
[edit] Using Contractors and/or consultants It has become customary to use consultants and contractors when introducing new quality practices and methodologies as in some instances the relevant skill-set and experience might not be available within the organisation. In addition, when new initiatives and improvements are required to boost the current quality system, or perhaps improve upon current manufacturing systems, the use of temporary consultants becomes a viable solution when allocating valuable resources. There are various types of consultants and contractors available in the market; most will have the skills needed to facilitate improvement activities such as Quality Management Systems (QMS) Auditing and procedural documentation writing. But the higher end consultants have knowledge and experience for implementing and improving manufacturing processes by using the latest cutting edge improvement activities such as CMMI, Six Sigma, Measurement Systems Analysis (MSA), Failure Mode and Effects Analysis (FMEA), Advance Product Quality Planning (APQP).
[edit] Academic resources • •
Quality Assurance in Education, ISSN 0968-4883, Emerald Publishing Group Accreditation and Quality Assurance: Journal for Quality, Comparability and Reliability in Chemical Measurement, ISSN: 1432-0517 (electronic) 0949-1775 (Paper), Springer
[edit] See also
• • • • • • • • • • • • • •
American Society for Quality Best practice CQE Data quality Data integrity Farm assurance GxP ISO 9000 Quality control Quality management Quality Management System Software Testing Software quality assurance Total Quality Management
[edit] References [edit] External links • • •
Pyzdek, T, "Quality Engineering Handbook", 2003, ISBN 0824746147 Godfrey, A. B., "Juran's Quality Handbook", 1999, ISBN 007034003X http://www.nrc.gov/reading-rm/doc-collections/cfr/part050/part050-appb.html
Retrieved from "http://en.wikipedia.org/wiki/Quality_assurance" Categories: Quality | Management | Evaluation | Quality assurance Hidden categories: Wikipedia articles needing context | Wikipedia introduction cleanup Views • • • •
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Quality control From Wikipedia, the free encyclopedia
Jump to: navigation, search For other uses, see Quality control (disambiguation). This article or section includes a list of references or external links, but its sources remain unclear because it lacks inline citations. You can improve this article by introducing more precise citations where appropriate. (February 2008)
The neutrality of this article is disputed. Please see the discussion on the talk page. (December 2007) Please do not remove this message until the dispute is resolved.
In engineering and manufacturing, quality control and quality engineering are involved in developing systems to ensure products or services are designed and produced to meet or exceed customer requirements. These systems are often developed in conjunction with other business and engineering disciplines using a cross-functional approach.
Contents [hide]
•
1 History o 1.1 Wartime production o 1.2 Post-war 2 Quality control o 2.1 Failure testing o 2.2 Statistical control o 2.3 Company quality o 2.4 Total quality control 3 See also
•
4 References
•
•
[edit] History When the first specialized craftsmen arose manufacturing tools for others, the principle of quality control was simple: "let the buyer beware" (caveat emptor). Early civil engineering projects, however, needed to be built to specifications. For instance, the four sides of the base of the Great Pyramid of Giza are perpendicular to within 3.5 arcseconds.
During the Middle Ages, guilds took the responsibility of quality control upon themselves. Royal governments purchasing material were interested in quality control as customers. For instance, King John of England appointed a certain William Wrotham to supervise the construction and repair of ships. Some centuries later, but also in England, Samuel Pepys, Secretary to the Admiralty, appointed multiple such overseers. The Industrial Revolution led to a system in which large groups of people performing a similar type of work were grouped together under the supervision of a foreman who also took on the responsibility to control the quality of work manufactured. Quality Assurance has developed a good deal during the last 80-90 years (in about 20 year intervals) from its inception to the current state of the art.
[edit] Wartime production During World War I, the manufacturing process became more complex, and foremen began to supervise large numbers of workers to ensure the quality of the work being produced. This period also introduced mass production and piecework, which created quality problems as workmen could now earn more money by the production of extra products, which in turn led to bad workmanship being passed on to the assembly lines. Due to the large amount of bad workmanship being produced, the first full time inspectors were introduced into the large-scale modern factory. These full time inspectors were the real beginning of inspection quality control, and this was the beginning of the large inspection organizations of the 1920s and 1930s, which were separately organised from production and big enough to be headed by superintendents. The systematic approach to quality started in industrial manufacture during the 1930s, mostly in the USA, when some attention was given to the cost of scrap and rework. With the impact of mass production, which was required during the Second World War, it became necessary to introduce a more stringent form of quality control which can be identified as Statistical Quality Control, or SQC. Some of the initial work for SQC is credited to Walter A. Shewhart of Bell Labs, starting with his famous one-page memorandum of 1924. This system came about with the realisation that quality cannot be inspected into an item. By extending the inspection phase and making inspection organizations more efficient, it provides inspectors with control tools such as sampling and control charts. SQC had a significant contribution in that it provided a sampling inspection system rather than a 100 per cent inspection. This type of inspection however did lead to a lack of realisation to the importance of the engineering of product quality.
For example, if you have a basic sampling scheme with an acceptance level of 4%, what happens is you have a ratio of 96% products released onto the market with 4% defective items – this obviously is a fair risk for any company/customer – unless you happen to be one of the unfortunate buyers of a defective item.
[edit] Post-war After World War II, the United States continued to apply the concepts of inspection and sampling to remove defective product from production lines. However, there were many individuals trying to lead U.S. industries towards a more collaborative approach to quality. Excluding the U.S., many countries' manufacturing capabilities were destroyed during the war. This placed American business in a position where advances in the collaborative approaches to quality were essentially ignored. After World War II, the U.S. sent General Douglas MacArthur to oversee the re-building of Japan. During this time, General MacArthur invited two key individuals in the development of modern quality concepts: W. Edwards Deming and Joseph Juran. Both individuals promoted the collaborative concepts of quality to Japanese business and technical groups, and these groups utilized these concepts in the redevelopment of the Japanese economy.
[edit] Quality control Quality assurance Quality assurance covers all activities from design, development, production, installation, servicing and documentation. This introduced the rules: "fit for purpose" and "do it right the first time". It includes the regulation of the quality of raw materials, assemblies, products and components; services related to production; and management, production, and inspection processes. One of the most widely used paradigms for QA management is the PDCA (Plan-DoCheck-Act) approach, also known as the Shewhart cycle.
[edit] Failure testing A valuable process to perform on a whole consumer product is failure testing, the operation of a product until it fails, often under stresses such as increasing vibration, temperature and humidity. This exposes many unanticipated weaknesses in a product, and the data is used to drive engineering and manufacturing process improvements. Often quite simple changes can dramatically improve product service, such as changing to mold-resistant paint or adding lock washer placement to the training for new assembly personnel.
[edit] Statistical control
Many organizations use statistical process control to bring the organization to Six Sigma levels of quality, in other words, so that the likelihood of an unexpected failure is confined to six standard deviations on the normal distribution. This probability is less than four one-millionths. Items controlled often include clerical tasks such as order-entry as well as conventional manufacturing tasks. Traditional statistical process controls in manufacturing operations usually proceed by randomly sampling and testing a fraction of the output. Variances of critical tolerances are continuously tracked, and manufacturing processes are corrected before bad parts can be produced.
[edit] Company quality During the 1980s, the concept of “company quality” with the focus on management and people came to the fore. It was realised that, if all departments approached quality with an open mind, success was possible if the management led the quality improvement process. The company-wide quality approach places an emphasis on three aspects :1. Elements such as controls, job management, adequate processes, performance and integrity criteria and identification of records 2. Competence such as knowledge, skills, experience, qualifications 3. Soft elements, such as personnel integrity, confidence, organisational 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. The approach to quality management given here is therefore not limited to the manufacturing theatre only but can be applied to any business activity: • • • • • • • •
Design work Administrative services Consulting Banking Insurance Computer software Retailing Transportation
It comprises a quality improvement process, which is generic in the sense it can be applied to any of these activities and it establishes a behaviour pattern, which supports the achievement of quality.
This in turn is supported by quality management practices which can include a number of business systems and which are usually specific to the activities of the business unit concerned. In manufacturing and construction activities, these business practices can be equated to the models for quality assurance defined by the International Standards contained in the ISO 9000 series and the specified Specifications for quality systems. Still, in the system of Company Quality, the work being carried out was shop floor inspection which did not control the major quality problems. This led to quality assurance or total quality control, which has come into being recently.
[edit] Total quality control Total Quality Control is the most necessary inspection control of all in cases where, despite statistical quality control techniques or quality improvements implemented, sales decrease. The major problem which leads to a decrease in sales was that the specifications did not include the most important factor, “What the customer required”. The major characteristics, ignored during the search to improve manufacture and overall business performance were: • • •
Reliability Maintainability Safety
As the most important factor had been ignored, a few refinements had to be introduced: 1. Marketing had to carry out their work properly and define the customer’s specifications. 2. Specifications had to be defined to conform to these requirements. 3. Conformance to specifications i.e. drawings, standards and other relevant documents, were introduced during manufacturing, planning and control. 4. Management had to confirm all operators are equal to the work imposed on them and holidays, celebrations and disputes did not affect any of the quality levels. 5. Inspections and tests were carried out, and all components and materials, bought in or otherwise, conformed to the specifications, and the measuring equipment was accurate, this is the responsibility of the QA/QC department. 6. Any complaints received from the customers were satisfactorily dealt with in a timely manner. 7. Feedback from the user/customer is used to review designs. 8. Consistent data recording and assessment and documentation integrity. 9. Product and/or process change management and notification.
If the original specification does not reflect the correct quality requirements, quality cannot be inspected or manufactured into the product. For instance, all parameters for a pressure vessel should include not only the material and dimensions but operating, environmental, safety, reliability and maintainability requirements. To conclude, the above forms the basis from which the philosophy of Quality Assurance has evolved, and the achievement of quality or the “fitness-for-purpose” is “Quality Awareness” throughout the company.
[edit] See also [edit] References • • • • • • •
Federal Standard 1037C Good Manufacturing Practice Good Automated Manufacturing Practice (GAMP) Corrective and Preventative Action (CAPA) MIL-STD-188 Pyzdek, T, "Quality Engineering Handbook", 2003, ISBN 0824746147 Godfrey, A. B., "Juran's Quality Handbook", 1999, ISBN 007034003
Retrieved from "http://en.wikipedia.org/wiki/Quality_control" Categories: Quality control | Management | Manufacturing | Production and manufacturing | Design for X Hidden categories: Articles lacking in-text citations | NPOV disputes from December 2007 | All NPOV disputes
(Redirected from Quality Assurance) Jump to: navigation, search The introduction to this article provides insufficient context for those unfamiliar with the subject. Please help improve the article with a good introductory style.
Quality assurance, or QA for short, refers to planned and systematic processes that provide confidence of a product's or service's effectiveness. More accurately, quality assurance is a standard for meeting customer requirements. It documents how a company will meet the requirements of a client or customer in a systematic, reliable fashion. It shows a companies commitment to delivering quality products and services to the purchaser. It does not however guarantee a quality product nor should the quality assurance logo or stamp of approval be placed on the product as it is the company and not the product or service that is quality assured.
Contents [hide]
• • • • •
1 History o 1.1 Early efforts to control the quality of production o 1.2 Wartime production o 1.3 Postwar 2 Quality assurance 3 Quality control activities o 3.1 Peer reviews o 3.2 Failure testing o 3.3 Statistical control o 3.4 Total quality control o 3.5 ISO 17025 4 Company quality 5 Using Contractors and/or consultants 6 Academic resources 7 See also 8 References
•
9 External links
•
• •
[edit] History
[edit] Early efforts to control the quality of production When the first specialized craftsmen arose manufacturing tools for others, the principle of quality was simple: "let the buyer beware" (caveat emptor). Early civil engineering projects needed to be built from specifications. For example in order to ensure the four sides of the base of the Great Pyramid of Giza would be perpendicular to within 3.5 arcseconds. During the Middle Ages, guilds took the responsibility of quality control upon themselves. Royal governments purchasing material were interested in quality control as customers. For this reason , King John of England appointed a certain William Wrotham to report about the construction and repair of ships. Some centuries later, but also in England, Samuel Pepys, Secretary to the Admiralty, appointed multiple such overseers. Prior to the extensive division of labor and mechanization resulting from the Industrial Revolution, it was possible for workers to control the quality of their own products. Working conditions then were more conducive to professional pride. The Industrial Revolution led to a system in which large groups of people performing a similar type of work were grouped together under the supervision of a foreman who was appointed to control the quality of work manufactured.
[edit] Wartime production During World War I, the manufacturing process became more complex, and the introduction of large numbers of workers being supervised by a foreman designated to ensure the quality of the work, which was being produced. This period also introduced mass production and piecework, which created problems as workmen could now earn more money by the production of extra products, which in turn led to bad workmanship being passed on to the assembly lines. Due to the large amount of bad workmanship being produced, the first full time inspectors were introduced into the large-scale modern factory. These full time inspectors were the real beginning of inspection quality control, and this was the beginning the large inspection organizations of the 1920s and 1930s, which were separately organised from production and big enough to be headed by superintendents. The systematic approach to quality started in industrial manufacture during the 1930s, mostly in the USA, when some attention was given to the cost of scrap and rework. With the impact of mass production, which was required during the Second World War, it became necessary to introduce a more appropriate form of quality control which can be identified as Statistical Quality Control, or SQC. Some of the initial work for SQC is
credited to Walter A. Shewhart of Bell Labs, starting with his famous one-page memorandum of 1924. This system came about with the realization that quality cannot be fully inspected into an important batch of items. By extending the inspection phase and making inspection organizations more efficient, it provides inspectors with control tools such as sampling and control charts. SQC had a significant contribution in that it provided a sampling inspection system where 100 per cent inspection was not practicable. This type of inspection however did lead to a lack of attention to the engineering activities for producinq quality. For example, if you have a basic sampling scheme with an acceptance level of 4%, what happens is you have a ratio of 96% products released onto the market with 4% defective items – this obviously is a fair risk if you are ensured that unfortunate buyers will not complain.
[edit] Postwar After World War II, the United States continued to apply the concepts of inspection and sampling to remove defective product from production lines. However, there were many individuals trying to lead U.S. industries towards a more comprehensive approach to quality. Excluding the U.S., many countries' manufacturing capabilities were destroyed during the war. This placed American business in a position where advances in the collaborative approaches to quality were essentially ignored. After World War II, the U.S. sent General Douglas MacArthur to oversee the re-building of Japan. During this time, General MacArthur involved two key individuals in the development of modern quality concepts: W. Edwards Deming and Joseph Juran. Both individuals promoted the collaborative concepts of quality to Japanese business and technical groups, and these groups utilized these concepts in the redevelopment of the Japanese economy.
[edit] Quality assurance Unlike Quality Control, Quality Assurance is an activity that is derived from business objectives. As Quality Control is a production activity, Quality Assurance is an on-going activity that serves as the eyes of upper-management. If a process activity does not respect the previously agreed-upon steps, then QA will report this to ensure corrective action. Quality assurance activities are executed on all development processes to help maintain an expected level of effectiveness.
[edit] Quality control activities
Quality control applies to all forms of products and services as a verification (testing) activity. This introduced the rules: "fit for purpose" and "do it right the first time". It includes the regulation of the quality of raw materials, assemblies, products and components; services related to production; and management, production, and inspection processes. The purpose is to detect defects at the earliest stages of development. Quality assurance is then applied to these processes to maintain the effectiveness of defect removal. One of the most widely used paradigms for Test management is the PDCA (Plan-DoCheck-Act) approach, also known as the Shewhart cycle.
[edit] Peer reviews Peer reviews are an integral part of Quality control activities. They are the most effective means of reducing defects during the development lifecycle.
[edit] Failure testing A valuable process to perform on a whole consumer product is failure testing, the operation of a product until it fails, often under stresses such as increasing vibration, temperature and humidity. This exposes many unanticipated weaknesses in a product, and the data is used to drive engineering and manufacturing process improvements. Often quite simple changes can dramatically improve product service, such as changing to mould-resistant paint or adding lock-washer placement to the training for new assembly personnel.
[edit] Statistical control Many organizations use statistical process control to bring the organization to Six Sigma levels of quality, in other words, so that the likelihood of an unexpected failure is confined to six standard deviations on the normal distribution. This probability is less than four one-millionths. Items controlled often include clerical tasks such as order-entry as well as conventional manufacturing tasks. Traditional statistical process controls in manufacturing operations usually proceed by randomly sampling and testing a fraction of the output. Variances of critical tolerances are continuously tracked, and manufacturing processes are corrected before bad parts can be produced. It's very necessary to monitor phase wise activities so that any variance is in any phase project can take action and save project deliverables of next phase from delayed and achieve customer satisfaction.
[edit] Total quality control
Deep Analysis of quality assurance practices and premisses used about them is the most necessary inspection control of all in cases where, despite statistical quality control techniques or quality improvements implemented, sales decrease. The major problem which leads to a decrease in sales was that the specifications did not include the most important factor, “What the specifications have to state in order to satisfy the customer requirements?”. The major characteristics, ignored during the search to improve manufacture and overall business performance were: • • • •
Reliability Maintainability Safety Strength
As the most important factor had been ignored, a few refinements had to be introduced: 1. Marketing had to carry out their work properly and define the customer’s specifications. 2. Specifications had to be defined to conform to these requirements. 3. Conformance to specifications i.e. drawings, standards and other relevant documents, were introduced during manufacturing, planning and control. 4. Management had to confirm all operators are equal to the work imposed on them and holidays, celebrations and disputes did not affect any of the quality levels. 5. Inspections and tests were carried out, and all components and materials, bought in or otherwise, conformed to the specifications, and the measuring equipment was accurate, this is the responsibility of the QA/QC department. 6. Any complaints received from the customers were satisfactorily dealt with in a timely manner. 7. Feedback from the user/customer is used to review designs. 8. Consistent data recording and assessment and documentation integrity. 9. Product and/or process change management and notification. If the original specification does not reflect the correct quality requirements, quality cannot be implemented into the product. For instance, all parameters for a pressure vessel should include not only the material and dimensions but operating, environmental, safety, reliability and maintainability requirements. To conclude, the above forms the basis from which the philosophy of Quality has evolved, and the achievement of quality or the “fitness-for-purpose” is “Quality Awareness” throughout the company.
The following are examples of best practice models that enhance the development process:
[edit] ISO 17025 ISO 17025 is an international standard that specifies the general requirements for the competence to carry out tests and or calibrations. There are 15 management requirements and 10 technical requirements. These requirements outline what a laboratory must do to become accredited. Management system refers to the organization's structure for managing its processes or activities that transform inputs of resources into a product or service which meets the organization's objectives, such as satisfying the customer's quality requirements, complying with regulations, or meeting environmental objectives. The CMMI (Capability Maturity Model Integration) model is widely used to implement Quality Assurance (PPQA) in an organization. The CMMI maturity levels can be divided in to 5 steps, which a company can achieve by performing specific activities within the organization.
[edit] Company quality During the 1980s, the concept of “company quality” with the focus on management and people came to the fore. It was realized that, if all departments approached quality with an open mind, success was possible if the management led the quality improvement process. The company-wide quality approach places an emphasis on four aspects :1. Elements such as controls, job management, adequate processes, performance and integrity criteria and identification of records 2. Competence such as knowledge, skills, experience, qualifications 3. Soft elements, such as personnel integrity, confidence, organizational culture, motivation, team spirit and quality relationships. 4. Infrastructure (as it enhances or limits functionality) The quality of the outputs is at risk if any of these aspects is deficient in any way. The approach to quality management given here is therefore not limited to the manufacturing theatre only but can be applied to any business or non-business activity: • • • • • • •
Design work Administrative services Consulting Banking Insurance Computer software Retailing
• • •
Transportation open source development education
It comprises a quality improvement process, which is generic in the sense it can be applied to any of these activities and it establishes a behaviour pattern, which supports the achievement of quality. This in turn is supported by quality management practices which can include a number of business systems and which are usually specific to the activities of the business unit concerned. In manufacturing and construction activities, these business practices can be equated to the models for quality assurance defined by the International Standards contained in the ISO 9000 series and the specified Specifications for quality systems. Still, in the system of Company Quality, the work being carried out was shop floor inspection which did not reveal the major quality problems. This led to quality assurance or total quality control, which has come into being recently.
[edit] Using Contractors and/or consultants It has become customary to use consultants and contractors when introducing new quality practices and methodologies as in some instances the relevant skill-set and experience might not be available within the organisation. In addition, when new initiatives and improvements are required to boost the current quality system, or perhaps improve upon current manufacturing systems, the use of temporary consultants becomes a viable solution when allocating valuable resources. There are various types of consultants and contractors available in the market; most will have the skills needed to facilitate improvement activities such as Quality Management Systems (QMS) Auditing and procedural documentation writing. But the higher end consultants have knowledge and experience for implementing and improving manufacturing processes by using the latest cutting edge improvement activities such as CMMI, Six Sigma, Measurement Systems Analysis (MSA), Failure Mode and Effects Analysis (FMEA), Advance Product Quality Planning (APQP).
[edit] Academic resources • •
Quality Assurance in Education, ISSN 0968-4883, Emerald Publishing Group Accreditation and Quality Assurance: Journal for Quality, Comparability and Reliability in Chemical Measurement, ISSN: 1432-0517 (electronic) 0949-1775 (Paper), Springer
[edit] See also
• • • • • • • • • • • • • •
American Society for Quality Best practice CQE Data quality Data integrity Farm assurance GxP ISO 9000 Quality control Quality management Quality Management System Software Testing Software quality assurance Total Quality Management
[edit] References [edit] External links • • •
Pyzdek, T, "Quality Engineering Handbook", 2003, ISBN 0824746147 Godfrey, A. B., "Juran's Quality Handbook", 1999, ISBN 007034003X http://www.nrc.gov/reading-rm/doc-collections/cfr/part050/part050-appb.html
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Quality control From Wikipedia, the free encyclopedia
Jump to: navigation, search For other uses, see Quality control (disambiguation). This article or section includes a list of references or external links, but its sources remain unclear because it lacks inline citations. You can improve this article by introducing more precise citations where appropriate. (February 2008)
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In engineering and manufacturing, quality control and quality engineering are involved in developing systems to ensure products or services are designed and produced to meet or exceed customer requirements. These systems are often developed in conjunction with other business and engineering disciplines using a cross-functional approach.
Contents [hide]
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1 History o 1.1 Wartime production o 1.2 Post-war 2 Quality control o 2.1 Failure testing o 2.2 Statistical control o 2.3 Company quality o 2.4 Total quality control 3 See also
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4 References
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[edit] History When the first specialized craftsmen arose manufacturing tools for others, the principle of quality control was simple: "let the buyer beware" (caveat emptor). Early civil engineering projects, however, needed to be built to specifications. For instance, the four sides of the base of the Great Pyramid of Giza are perpendicular to within 3.5 arcseconds.
During the Middle Ages, guilds took the responsibility of quality control upon themselves. Royal governments purchasing material were interested in quality control as customers. For instance, King John of England appointed a certain William Wrotham to supervise the construction and repair of ships. Some centuries later, but also in England, Samuel Pepys, Secretary to the Admiralty, appointed multiple such overseers. The Industrial Revolution led to a system in which large groups of people performing a similar type of work were grouped together under the supervision of a foreman who also took on the responsibility to control the quality of work manufactured. Quality Assurance has developed a good deal during the last 80-90 years (in about 20 year intervals) from its inception to the current state of the art.
[edit] Wartime production During World War I, the manufacturing process became more complex, and foremen began to supervise large numbers of workers to ensure the quality of the work being produced. This period also introduced mass production and piecework, which created quality problems as workmen could now earn more money by the production of extra products, which in turn led to bad workmanship being passed on to the assembly lines. Due to the large amount of bad workmanship being produced, the first full time inspectors were introduced into the large-scale modern factory. These full time inspectors were the real beginning of inspection quality control, and this was the beginning of the large inspection organizations of the 1920s and 1930s, which were separately organised from production and big enough to be headed by superintendents. The systematic approach to quality started in industrial manufacture during the 1930s, mostly in the USA, when some attention was given to the cost of scrap and rework. With the impact of mass production, which was required during the Second World War, it became necessary to introduce a more stringent form of quality control which can be identified as Statistical Quality Control, or SQC. Some of the initial work for SQC is credited to Walter A. Shewhart of Bell Labs, starting with his famous one-page memorandum of 1924. This system came about with the realisation that quality cannot be inspected into an item. By extending the inspection phase and making inspection organizations more efficient, it provides inspectors with control tools such as sampling and control charts. SQC had a significant contribution in that it provided a sampling inspection system rather than a 100 per cent inspection. This type of inspection however did lead to a lack of realisation to the importance of the engineering of product quality.
For example, if you have a basic sampling scheme with an acceptance level of 4%, what happens is you have a ratio of 96% products released onto the market with 4% defective items – this obviously is a fair risk for any company/customer – unless you happen to be one of the unfortunate buyers of a defective item.
[edit] Post-war After World War II, the United States continued to apply the concepts of inspection and sampling to remove defective product from production lines. However, there were many individuals trying to lead U.S. industries towards a more collaborative approach to quality. Excluding the U.S., many countries' manufacturing capabilities were destroyed during the war. This placed American business in a position where advances in the collaborative approaches to quality were essentially ignored. After World War II, the U.S. sent General Douglas MacArthur to oversee the re-building of Japan. During this time, General MacArthur invited two key individuals in the development of modern quality concepts: W. Edwards Deming and Joseph Juran. Both individuals promoted the collaborative concepts of quality to Japanese business and technical groups, and these groups utilized these concepts in the redevelopment of the Japanese economy.
[edit] Quality control Quality assurance Quality assurance covers all activities from design, development, production, installation, servicing and documentation. This introduced the rules: "fit for purpose" and "do it right the first time". It includes the regulation of the quality of raw materials, assemblies, products and components; services related to production; and management, production, and inspection processes. One of the most widely used paradigms for QA management is the PDCA (Plan-DoCheck-Act) approach, also known as the Shewhart cycle.
[edit] Failure testing A valuable process to perform on a whole consumer product is failure testing, the operation of a product until it fails, often under stresses such as increasing vibration, temperature and humidity. This exposes many unanticipated weaknesses in a product, and the data is used to drive engineering and manufacturing process improvements. Often quite simple changes can dramatically improve product service, such as changing to mold-resistant paint or adding lock washer placement to the training for new assembly personnel.
[edit] Statistical control
Many organizations use statistical process control to bring the organization to Six Sigma levels of quality, in other words, so that the likelihood of an unexpected failure is confined to six standard deviations on the normal distribution. This probability is less than four one-millionths. Items controlled often include clerical tasks such as order-entry as well as conventional manufacturing tasks. Traditional statistical process controls in manufacturing operations usually proceed by randomly sampling and testing a fraction of the output. Variances of critical tolerances are continuously tracked, and manufacturing processes are corrected before bad parts can be produced.
[edit] Company quality During the 1980s, the concept of “company quality” with the focus on management and people came to the fore. It was realised that, if all departments approached quality with an open mind, success was possible if the management led the quality improvement process. The company-wide quality approach places an emphasis on three aspects :1. Elements such as controls, job management, adequate processes, performance and integrity criteria and identification of records 2. Competence such as knowledge, skills, experience, qualifications 3. Soft elements, such as personnel integrity, confidence, organisational 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. The approach to quality management given here is therefore not limited to the manufacturing theatre only but can be applied to any business activity: • • • • • • • •
Design work Administrative services Consulting Banking Insurance Computer software Retailing Transportation
It comprises a quality improvement process, which is generic in the sense it can be applied to any of these activities and it establishes a behaviour pattern, which supports the achievement of quality.
This in turn is supported by quality management practices which can include a number of business systems and which are usually specific to the activities of the business unit concerned. In manufacturing and construction activities, these business practices can be equated to the models for quality assurance defined by the International Standards contained in the ISO 9000 series and the specified Specifications for quality systems. Still, in the system of Company Quality, the work being carried out was shop floor inspection which did not control the major quality problems. This led to quality assurance or total quality control, which has come into being recently.
[edit] Total quality control Total Quality Control is the most necessary inspection control of all in cases where, despite statistical quality control techniques or quality improvements implemented, sales decrease. The major problem which leads to a decrease in sales was that the specifications did not include the most important factor, “What the customer required”. The major characteristics, ignored during the search to improve manufacture and overall business performance were: • • •
Reliability Maintainability Safety
As the most important factor had been ignored, a few refinements had to be introduced: 1. Marketing had to carry out their work properly and define the customer’s specifications. 2. Specifications had to be defined to conform to these requirements. 3. Conformance to specifications i.e. drawings, standards and other relevant documents, were introduced during manufacturing, planning and control. 4. Management had to confirm all operators are equal to the work imposed on them and holidays, celebrations and disputes did not affect any of the quality levels. 5. Inspections and tests were carried out, and all components and materials, bought in or otherwise, conformed to the specifications, and the measuring equipment was accurate, this is the responsibility of the QA/QC department. 6. Any complaints received from the customers were satisfactorily dealt with in a timely manner. 7. Feedback from the user/customer is used to review designs. 8. Consistent data recording and assessment and documentation integrity. 9. Product and/or process change management and notification.
If the original specification does not reflect the correct quality requirements, quality cannot be inspected or manufactured into the product. For instance, all parameters for a pressure vessel should include not only the material and dimensions but operating, environmental, safety, reliability and maintainability requirements. To conclude, the above forms the basis from which the philosophy of Quality Assurance has evolved, and the achievement of quality or the “fitness-for-purpose” is “Quality Awareness” throughout the company.
[edit] See also [edit] References • • • • • • •
Federal Standard 1037C Good Manufacturing Practice Good Automated Manufacturing Practice (GAMP) Corrective and Preventative Action (CAPA) MIL-STD-188 Pyzdek, T, "Quality Engineering Handbook", 2003, ISBN 0824746147 Godfrey, A. B., "Juran's Quality Handbook", 1999, ISBN 007034003
Retrieved from "http://en.wikipedia.org/wiki/Quality_control" Categories: Quality control | Management | Manufacturing | Production and manufacturing | Design for X Hidden categories: Articles lacking in-text citations | NPOV disputes from December 2007 | All NPOV disputes
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