QA (Quality assurance) Versus QC (Quality control) 


The terms “Quality Assurance (QA)" and “Quality Control (QC)” can be confusing or even misunderstood to mean the same thing. In this article, the goal is to clarify the real meaning of the two terms and explain their differences.

The Differences Between QA and QC

Both quality assurance and quality control fall under quality management, which has four basic components: quality planning, quality assurance, quality control and quality improvement. Even though humans have been concerned with quality since the production of the earliest tools, our understanding of what goes into quality management has evolved dramatically over the years. 

During the height of the Industrial Revolution, quality was ensuring that engineering requirements were met in final products, and strict quality control measures dominated the industry. In the 1950s, quality management expanded to include quality assurance as public health and safety had become paramount. Today, quality management includes all activities of the overall management function that determine the quality policy, objectives, responsibilities and their implementation, as explained by the ASQ Audit Division.

To give a clear definition of quality assurance, we can say that it encompasses all the planned and systematic activities implemented within the quality system that can be demonstrated to provide confidence that a product or service will fulfill requirements for quality.

  • Quality assurance focuses on improving the processes needed to make the end product work or the processes that ensure that acceptable quality can be produced. 
  • Quality assurance is proactive, which means that it is done even before the product is created
  • Quality assurance attempts to prevent defects before they occur in the first place.
  • It is the responsibility of everyone on the team involved in product development. 
  • The main tool of quality assurance is quality audits.

Quality control, on the other hand, encompasses the operational techniques and activities used to fulfill requirements for quality. 

  • Quality control focuses on the actual product, making sure that the product is in line with specifications.
  • It is reactive, which means that it happens after key processes leading to the creation of the product have taken place.
  • Quality control attempts to find defects to ensure that the discovered defects can be fixed.
  • It is the responsibility of a specific team to test the product for defects.
  • Testing is the main tool of quality control. 
  • In summary, quality control deals with the product, while quality assurance deals with the processes surrounding the creation of the product. With effective quality assurance, there should be no discovered failures during the quality control process though this might seem ideal.

Software QA

In software development, the term software quality assurance (SQA) is used to refer to the monitoring of the software engineering processes and methods used to ensure quality. Its purpose is to maintain quality and keep customers satisfied. 

According to Dave Nielsen, Sr. Developer Advocate for the Trusted Analytics Platform (TAP) in the Analytics Solutions Group, within DCG at Intel, “SQA encompasses the entire software development process, which includes processes such as requirements definition, software design, coding, source code control, code reviews, software configuration management, testing, release management, and product integration.”