Quality Assurance vs Quality Control

Quality Assurance Vs Quality ControlI met a guy few years before while attending a training course; he was working as a QA/QC (Quality Assurance/Quality Control) Engineer in a construction company. We had little chat together during which I asked him what he does as a QA/QC Engineer in his company. He replied that just walks around and checks whether everything is going on as planned or not. If he observes any deviation from the plan or something wrong, he will make a note and process it for further investigation or action. I said fine, that takes care of QC part of your job but what is your role as a QA?  I again got the same reply.

The point is, a lot of times many experienced professionals who work as a Quality Assurance or a Quality Control Engineers do not know the difference between the roles and responsibilities QC vis-à-vis  QA.

For some people, it is very difficult to differentiate the difference between Quality Assurance and Quality Control processes; although, the difference between them is pretty clear.

This topic is also very important from a PMP Certification examination point of view. You can expect to see more than two or three questions from this topic in the PMP Certification Exam.

Verify Scope is another process which many people confuse with Quality Control Process.

Therefore, I am posting two blogs covering all of it. This is part one, and here I will discuss about Quality Assurance and Quality Control, and the next blog post will deal with Quality Control and Verify Scope.

Quality AssuranceQuality Assurance

The definition of Quality is “fitness to use” and “conform to requirements”. Quality Assurance is a method which makes sure that any process developed to generate a product is such that the product that comes out from the process must be fit, and conforms to all stated requirements. To develop the process, the Quality Assurance process takes input from the Quality Control process.

Quality Assurance is a proactive process, and starts at the very beginning of the project to understand the stated & non-stated requirements, and expectations, and creates a plan to meet those requirements and expectations.

Quality Audit is an example of Quality Assurance. Other examples are training, process definition, selection of tools, etc.

The primary purpose of Quality Assurance is to prevent defects in deliverables at the planning process stage itself to avoid rework.

Quality ControlQuality Control

If the Quality Assurance is a process based approach then the Quality Control is a product based approach. Quality Control is concerned with the operational activities and techniques that are used to fulfill the requirements of quality.

The Quality Control functions start once the projects work has begun. It is a reactive approach and helps to find defects in deliverables. Site inspection and testing are few examples of the Quality Control Process.

The main purpose of the Quality Control Process is to see if the deliverables are defect free, and acceptable as per quality requirements and standards set in the Quality Assurance process. If deliverables are not as per the requirements, suitable corrective action will be taken.

Quality Assurance and Quality Control processes are dependent on each other. The Quality Control receives the input from the Quality Assurance, and in turns gives feedback to the Quality Assurance so that Quality Assurance could validate the process.

For example, if the project team finds any defects while executing the project, it will correct the error by work around, and this feedback is sent to Quality Assurance for further investigation to take corrective actions in the process so that this error should never happen again in future.

In the same way the Quality Control people will follow the process defined by Quality Assurance so that these defects do not recur.

Key Points

  • In Quality Assurance, processes are planned to avoid the defects and assure quality.
  • Quality Control deals with finding the defects and correcting them while making the product.
  • Quality Assurance is a Proactive approach.
  • Quality Control is a reactive approach.
  • Quality Assurance is a process based approach.
  • Quality Control is a product based approach.

I hope that the differences between Quality Assurance and Quality Control are clear to you. Since these processes are very tightly linked, sometimes it is difficult to identify the subtle differences between the two. And to add to the confusion, in some small and medium-sized organisations both these two processes are performed by the same department which causes a lot of chaos and conflicts in responsibilities.


  1. Jacqui Yoon says

    Thank you for posting your blog and sharing your insights and well organized thoughts and explanations. I wish I had come across your blog earlier in my travels, for today I failed my first attempt at passing the PMP exam. I was ill prepared, was too dependent on self-study via an internet website and life happens too often when one is trying to dig a hole and study in it…life always finds you to drag you away from all the fun of studying. Anyhoo, love your writing style which is not too pedantic and is not a repeat of what is found in the PMBOK which is a dread of a read for me. I never took the time to really discern between the two and it came to haunt me today.

    • Fahad Usmani says

      Hello Jacqui,

      I am very sorry to hear that you failed the PMP test in your first attempt. However, you still have you more attempts left with you.

      Now, it is time for you take firm determination to pass the PMP exam. Schedule the exam and start preparing for it and let me know if you require any kind of assistance from me.

      Good luck.

  2. Saleem Angillath says

    Hello Fahad
    I passed the PMP in first attempt. Your blog has helped me a lot in preparing for the exam. Thank you very much. Yours is an outstanding blog and very informative for all PMP aspirant and to others who are interested in PM. Well written and informative. Still i’m following your blog for latest articles on PMP. All the best and expecting more from you.
    Saleem Angillath

    • Fahad Usmani says

      Congratulations Saleem for passing the PMP Exam!

      I hope this certification will help you to grow your career. Thanks for sharing your happiness here at PMSC.

      Stay in touch.


  3. Ravindra says


    I do find your articles good. For some reason, I am not able to understand this article. Can you please help me?

    I understand that the QA ensures that the processes are set correctly to develop the product and the QC ensures that the final product is as per the requirements or not. Is my understanding correct?

    I did not understand how QA takes inputs from QC and QC takes inputs from QA. Can you give me an example? Thanks for your help.

    • Fahad Usmani says

      Hello Ravindra,

      Your understanding is correct.

      Quality Assurance develops the procedures, hence input for the Quality Control process.

      During Quality Control, if you see that certain procedure needs some improvement or causing any trouble, then you can provide feedback to Quality Assurance to improve the procedures, hence input to Quality Assurance.

  4. Ravindra says


    Thanks a lot for your reply. It clears my doubt.

    What is your suggestion on taking on-line training? Now, I am doing the preparation on my own and don’t know whether i am in the correct direction. Any suggestions you can give would be appreciated.


  5. Vijay says

    Help me to answer this question …..?

    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

    I found that answer is B, but why ?….In PMBOK, under Quality Control ( cause and effect daigram’s are explained …..so doesn’t it fall under Quality control …?

    Thanks in advance.

    • Fahad Usmani says

      See what the Joe is doing. He is only reviewing the processes used by his company so that the defects (occurred in past projects) could be removed. This is the job of quality assurance to develop a process in such way to avoid any defect.

      In Quality Control Process, the project manager takes the sample or randomly checks the process in running project.

      Therefore, the answer B is correct.

  6. Abhilash VJ says

    Hi Fahad,

    I’m a Recruitment Consultant in the oil & gas industry.

    This blog is fantastic and very well explained!!

    Thank you very much!

    Abhilash VJ

  7. Prasanna Kumar KR says

    Hi Fahad,
    Just wanted to say the super work you are doing by providing clear info in your blogs. I just came to know about this website yesterday, one day before my exam… I spent about 2 – 3 hours reading all your articles, which made concepts crystal clear and I passed PMP today. Keep up the excellent work :)

    Prasanna Kumar K R, PMP

  8. Daleep says

    Going for exam in next 2 days…. I must say your articles and blogs are really helping thanks for great work!

  9. Iftikhar Ali says

    Today I can say I am QA/QC inspector but after reading your blog not before.
    I love your comprehensive words which very simple & understood for all.
    I love ? with fahad usmani blog.

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