Quality assurance 305224 225572380 2008-07-14T10:58:43Z Northenpal 7473562 /* Quality assurance activities */ added text to seperate the QC text from the QA text. {{context}} '''Quality assurance''', or '''QA''' for short, is the set of planned and systematic actions necessary to provide appropriate confidence that a product or service will satisfy the requirements for quality. ==History== ===Early efforts to control the quality of production=== When the first specialized [[craft]]smen 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 [[specification]]s in order to ensure the four sides of the base of the [[Great Pyramid of Giza]] will be perpendicular to within 3.5 [[arcsecond]]s. During the [[Middle Ages]], [[guild]]s 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. === 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 [[product (business)|products]], which in turn led to bad workmanship being passed on to the [[assembly line]]s. Due to the large amount of bad workmanship being produced, the first full time [[inspector]]s 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 [[1920]]s and [[1930]]s, which were separately organised from production and big enough to be headed by [[Superintendent (construction)|superintendent]]s. The systematic approach to quality started in industrial manufacture during the [[1930]]s, 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 a important batch of items . By extending the inspection phase and making inspection organizations more efficient, it provides inspectors with control tools such as [[Theoretical sampling|sampling]] and [[control chart]]s. 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. === 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. == Quality control activities == Quality control applies to all forms of products and services. 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 Test management is the [[PDCA]] (Plan-Do-Check-Act) approach, also known as the [[Shewhart cycle]]. === 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 [[weakness]]es in a product, and the data is used to drive engineering and manufacturing [[process improvement]]s. 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. === 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 deviation]]s on the [[normal distribution]]. This probability is less than four [[1 E-6|one-millionth]]s. Items controlled often include [[clerical task]]s 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. === 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 [[sale]]s was that the [[specification]]s 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 As the most important factor had been ignored, a few refinements had to be introduced: # Marketing had to carry out their work properly and define the customer’s specifications. # Specifications had to be defined to conform to these [[requirement]]s. # Conformance to specifications i.e. [[drawing]]s, standards and other relevant documents, were introduced during manufacturing, [[planning]] and control. # Management had to confirm all [[operator]]s are equal to the work imposed on them and holidays, celebrations and disputes did not affect any of the quality levels. # Inspections and [[Quality control testing|test]]s were carried out, and all [[component]]s and [[material]]s, bought in or otherwise, conformed to the specifications, and the [[measuring equipment]] was [[accurate]], this is the responsibility of the QA/QC department. # Any [[complaint]]s received from the customers were satisfactorily dealt with in a timely manner. # Feedback from the user/customer is used to review designs. # Consistent data recording and assessment and documentation integrity. # 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 [[dimension]]s 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: ===ISO 17025=== [[ISO 17025]] is an [[international standard]] that specifies the general requirements for the competence to carry out tests and or [[calibration]]s. 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. ==Company quality== During the [[1980]]s, the concept of “company quality” with the focus on [[management]] and [[people]] came to the fore. It was realized that, if all [[Departmentalization|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 :- # Elements such as controls, job management, adequate processes, performance and integrity criteria and identification of records # Competence such as knowledge, skills, experience, qualifications # Soft elements, such as personnel [[integrity]], [[confidence]], [[organizational culture]], [[motivation]], [[team spirit]] and quality relationships. # 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 system]]s 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 [[Specification]]s 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. ==Using Contractors and/or consultants== It has become customary to use [[consultant]]s 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 [[Six Sigma]], [[Measurement Systems Analysis]] (MSA), [[Failure Mode and Effects Analysis]] (FMEA), [[Advance Product Quality Planning]] (APQP). == 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 ==See also== *[[American Society for Quality]] *[[Best practice]] *[[CQE]] *[[Data quality]] *[[Data integrity]] *[[GxP]] *[[ISO 9000]] *[[Quality control]] * [[Quality management]] *[[Quality Management System]] *[[Software Testing]] *[[Software quality assurance]] *[[Total Quality Management]] ==References== {{reflist}} ==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 [[Category:Quality]] [[Category:Management]] [[Category:Evaluation]] [[Category:Quality assurance| ]] [[cs:Quality assurance]] [[es:Garantía de calidad]] [[fr:Assurance qualité]] [[it:Assicurazione di qualità]] [[he:הבטחת איכות]] [[ja:品質保証]] [[sv:Kvalitetssäkring]]