Quality Assurance vs Quality Control | QA and QC | QA vs QC Compared
Whether it is a product, process, service or a system, quality is of paramount importance. Quality control, and quality assurance are two terms that are often encountered in any organization and people are often confused by the difference between these two terms. Though closely related, and basically concerned with quality, these are different approaches taken for achieving similar ends. This article will highlight the features of quality assurance and quality control to enable to appreciate the terms in a better manner.
While quality control is a set of activities designed to evaluate a developed product, quality assurance or guarantee pertains to activities that are designed to ensure that the development and maintenance process is adequate and the system meets its objectives. Quality control focuses on finding defects or anomalies in the deliverables and checking if the defined requirements are the right requirements. Testing is one example of a quality control activity, but there are many more such activities that make up quality control.
Quality assurance ensures that the process is well defined and appropriate. Some examples of quality assurance are methodology and standards development. Any quality assurance review would typically focus on the process aspect of a project or task, for example, are requirements being defined at a level of detail that is accepted and proper.
The most notable difference between quality assurance and quality control is that while QC is product oriented, QA is process oriented. Since testing checks the quality of a product, it classifies in the domain of QC. When you are testing a product for quality, you are not assuring its quality, you are controlling it. Another differentiation between QA and QC is that while QA makes sure that what you are doing are right things in the right manner while QC ensures that the results of what you have done are as per your expectations.
The difference between QA and QC is also one of power and control. QC is under control of development while QA controls development. QA normally precedes QC. QA is undertaken before starting a project whereas QC begins once the project has been completed. During QA, requirements of customers are defined while during QC, the product is tested to ensure it meets the quality set out initially. As such, QA is a proactive or preventive measure to avoid defects whereas QC is a corrective measure to identify any defects so as to correct them.
However, both QC and QA are highly interdependent. The QA department relies largely on the feedback it receives from the QC department. If there are any problems, the same are conveyed by QC department to QA department which makes suitable changes in the process so as to avoid these problems in future.
Summary
Both quality assurance and quality control have same objective but they differ in approaches and style. They are strongly interdependent which makes it difficult to pinpoint the differences. To make matters worse, in some organizations, both functions are performed by a single department.