Quality Assurance and Quality Control

Quality Assurance | Basic Concepts

Software QA involves the entire software development PROCESS - monitoring and improving the process, making sure that standards and procedures are followed, and ensuring that problems are found and dealt with. It is oriented to 'prevention'.

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-Do- Check-Act) approach, also known as the Shewhart cycle. The main goal of QA is to ensure that the product fulfills or exceeds customer expectations.

Quality Control | Basic Concepts

Quality Control is a technique for maintaining planned levels of quality in software development processes. It include, the act of measuring performance of a control subject, comparing performance to plans, and taking corrective action when actual performance deviates significantly from plans.

Quality control is a particular application of the standard process control feedback loop. The basic steps of process control are:

Establish plans and standards of performance
2. Perform work according to plan
3. Measure performance related to plan.
4. If actual performance deviates significantly from plan, take corrective action to bring performance back into line with plan.

Quality control describes the directed use of testing to measure the achievement of a specified standard. Quality control is a formal use of testing. Roughly, you test to see if something is broken, and with quality control you set limits that say, in effect, if this particular stuff is broken then whatever you're process fails.

Diagram of quality control process:

Difference between Quality Assurance and Quality Control

Although the two terms are often considered synonymous, a good working definition is that:

(a) QA refers to the set of practices and procedures which are intended to maximize the chances that the product or service will satisfy the client's requirements, at a reasonable cost.

(b) QC refers to the procedures used to verify the level of quality achieved, and if it is inadequate, to detect the source of the problem and remedy it, if possible.