What is Quality Assurance (QA)?

There is no commonly agreed definition of quality assurance. It varies across industries, organizations or even people. Since it bears the word "quality", it gets involved whenever there is quality problem.

Based on the Cambridge Advanced Learner's Dictionary, the word assurance carries several meanings:

1. a promise;
2. confidence;
3. a type of insurance against events which will certainly happen, such as death, not ones which may happen, such as illness, fire or having your property stolen.

In other words, assurance represents a promise or a level of confidence or a type of insurance against events which will certainly happen. When it is used in the context of quality as "quality assurance", it represents a promise or confidence level in quality. To achieve the promise or confidence level, some types of insurance or measure will be required against adverse events which will certainly happen.

In view of the above, I think "Quality Assurance" should be associated with things to protect the quality promise of a product from adverse events. Therefore, we could define "quality assurance" as:

Something to insure promised quality of a product from adverse events.

Very often, organizations employs system, standards and process to ensure promised quality is fulfilled consistently and repeatedly. Therefore, quality assurance could also be defined as:

System, standards and/or activities that enable an organization to consistently and repeatedly deliver products that satisfy customer's expected quality.