Difference between Quality Assurance and Quality Control

Hi guys

I'm schedule to take the test next week, doing my last review I still have not clear difference between Quality Assurance and Quality Control processes, have some definitions but when I faced questions usually got wrong.

Thanks for your help

admin's picture

Suppose you are manufacturing Coke.  QA would ensure that you have all the right processes in place to manufacture and test the quality of the coke. Like the machines , people, recording mechanism etc. QC is doing the actual testing on finished product. So when the coke bottle is out you do a sample test and it would either pass or fail the Q standards.

So QC is to do with testing and verification after the deliverable is done and QA is before the deliverable is made. Like giving trainings to people, Auditing the process, ensuring everyone understands the process etc are all QA activities.

 though the intended reply was for someone else, i too got the clear picture now about QA & QC. thanks a lot.

Hi Admin, thanks for your reply, now is more clear.

Look the following question (I know should be post it in a different thread) but is related to QA and QC


Joe is a project manager on an industrial design project. He has found a pattern of defects occurring in all of his projects over the past few years and he thinks there might be a problem in the process his company is using that is causing it. He uses Ishikawa diagrams to come up with the root cause for this trend over projects so that he can make recommendations for process changes to avoid this problem in the future. What process is he doing?

A. Plan Quality

B. Perform Quality Assurance

C. Perform Quality Control

D. Qualitative Risk Analysis


Answer is B. Why?

If you see the word "process", that right away is Quality Assurance.  

Hi Admin, just one comment more

You put:

"So QC is to do with testing and verification after the deliverable is done and QA is before the deliverable is made"

But the Quality Control Measurements (Output of QC) are an input to QA Process, so this indicate that QC goes first that QA?

Thanks a lot for the time you use for reply this questions. Really appreciated


This is an iterative process.  You develop and put in place QA first and establish metrics.  In QC you actually measure the deliverables to verify those metrics are met.  If not- either process is wrong or established metrics is unrealistic to achieve - that in turn serves as an input to revisit QA and make appropriate changes/revisions and the subsequent deliverables will be measured in QC per the new QA guidelines and so on. 


Quality Control is product/service testing.  Quality Assurance is process checking/audit.  

Quality Control is checking to ensure that you build the right product (Testing).  

Quality Assurance is checking to ensure that you build the product right (Process Audit).  

If you believe you may have pattern development in your house or office quality inspection services, you can seek the  services of an established pattern examination organization to come out for an examination of the property.