Quality Control & Quality Assurance
Quality has been variously perceived and defined e.g. doing the right things, doing the right way, doing it right the first time, doing it in time, receiveing right product for use, meeting the expectations etc. I feel the best and crisp definition of quality is 'suitability for purpose'. Quality Control and Quality Assurance are two concepts of quality. Quality Control (QC) is older than Quality Assurance (QA) in terms of genesis. However, it is important to understand that despite QC being older concept than QA, both are imperative. They do not outdo or replace each other. QC and QA, both are put into use for continuous improvement of product quality and delivery.
As the requirements for quality products increased, the manufacturers developed ways and means to ensure that only the quality products are delivered in market, and defective products are retained. The mechanism so evolved for preventing the delivery of defective product was termed as quality control.
Quality Control (QC) is a set of activities for ensuring quality in delivered products through testing, identification and correction of defects. It is a post-production, reactive process meant to monitor and verify that delivered product meets the defined quality standards. It begins after the product has been manufactured. It is exploratory in nature and intends to identify, and correct the error or defective product.
Quality Assurance (QA) is set of activities for ensuring quality in the development and manufacturing processes to achieve desired outcome. It focuses on preventing defects by facilitating the use of appropriate tools and techniques, methods, materials, trainings, measurements and analysis etc. QA provides confidence that processes are established to give desired outcome, and continuously improved.
QA is a proactive exercise that promotes quality concepts resulting in prevention of defects. It improves how we do things as it aims to make the processes so stringent that the outcome meets the desired specifications without any defect. It establishes a good quality management system and the assesses its adequacy. Internal audit, verification, analysing pattern of defects etc. are examples of QA.