Quality assurance, or QA for short, refers to planned and systematic production processes that provide confidence in a product’s suitability for its intended purpose. It is a set of activities intended to ensure that products (goods and/or services) satisfy customer requirements in a systematic, reliable fashion. QA cannot absolutely guarantee the production of quality products, unfortunately, but makes this more likely.
Two key principles characterize 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 lowly bottom-of-the-range goods can be considered quality items if they meet a market need.
Quality assurance versus quality control
Whereas quality control emphasizes testing and blocking the release of defective products, quality assurance is about improving and stabilizing production and associated processes to avoid or at least minimize issues that led to the defects in the first place. However, QA does not necessarily eliminate the need for QC: some product parameters are so critical that testing is still necessary just in case QA fails.
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 improvement 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.
Many organizations use statically 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 on the normal distribution. This probability is less than one-millions . 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 in critical tolerances are continuously tracked and where necessary corrected before bad parts are produced.
Total quality control
Deep analysis of QA practices and premises 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 specification 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:
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 equipments 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.
The final component of materials management is standards compliance. There are standards that are followed in supply chain management that are critical to a supply chain’s function. For example, a supply chain that uses just-in time or lean replenishment requires absolute perfection in the shipping of parts and material from purchasing agent to warehouse to place of destination. Systems reliant on vendor-managed inventories must have up-to-date computerized inventories and robust ordering systems for outlying vendors to place orders on. Materials management typically insures that the warehousing and shipping of such components as are needed follows the standards required to avoid problems. This component of materials management is the fastest changing part, due to recent innovations in SCM and in logistics in general, including outsourced management of ware housing, mobile computing, and real-time logistical inventories