Quality Assurance (QA) and Quality Control (QC) have some overlap but for the most part they are very different. Here are some differences between QA and QC I can think of off the top of my head.
QA builds quality-boosting behaviors and activities into end-to-end process like an SDLC (software development lifecycle). QA participates in initial storyboarding (conversant with layout/design principles in a website or program interface). QA can help write User Stories and even help break them into tasks. QA reviews requirements and can write them if necessary. QA ensures there is a requirements matrix for testability and requirements verification. QA includes code-activity choices such as pair programming and inspections. QA informs structures such as levels of modularity for easier reuse, rework, fixes, and isolating defects in the future. QA might even inform choices such as xml database vs. sql database depending on type of data served and performance. QA helps with stakeholder expectations management, negotiating project schedule to fit more QA time, and communicating the efficiencies and savings of catching issues early in the process. QA ensures all the steps in the process of creating a product are orchestrated to generate fewest possible errors with most efficient use of time.
QC writes and carries out test plans, use cases, test cases, and test scripts (manual and automated). If you are asking at this point, “What’s the difference between a use case and a test case?”, you need to read my other article on the difference between a use case and a test case. QC tests for quality as defined by requirements. The requirements matrix that QA made happen, is put into use by QC. Explicit requirements matrix verification is an additional quality step beyond the standard battery of test scripts. QC writes defect reports. QC provides a sign-off step.
Overlap occurs in QA/QC especially in the real world where both are one department, or where the QA manager and the QC manager are the same person. The QA/QC merger is fairly common, so you need to be aware of the different skills and talents required when you fill the two roles with one person. Whether you get adequate coverage in both QA and QC arenas depends on who fills the joint role. Just remember it is a joint role, not a normal single role and not an easy position to fill. I’ve thought of a lot more comparisons since I started writing, but that’s all for this article (blogs should be kept short and it’s getting late).
Footnote: I decided to write my two cents on this topic after reading a colleague’s (Danny Faught) related comment on LinkedIn (you have to be logged-in to LinkedIn to follow the link).