Quality Assurance vs Quality Control

July 26, 2020
Fahad Usmani
Quality Assurance vs Quality Control

Quality assurance and quality control are most important processes for any project, as the project’s success depends on these processes.

Every project has a quality control section to take care of these functions. The quality assurance function usually stays with the organization and the quality control section has to communicate with the organization to coordinate between these two processes.

由于这些过程是连接并在协调中起作用的,因此许多专业人员,尤其是在中小型组织中工作的专业人员,都不了解他们的差异。

这让我想起了一个交互在my ISO 9001 training course a few years back. I met with many professionals involved in quality management. These people were all from different backgrounds and were working in various fields.

One of the guys I met told me he was working as a QA/QC engineer in his company. I questioned him about his job responsibilities and his duties.

He replied that he walks around and sees if everything is going as planned or not, checks the items for correctness, and he takes propercorrective actionif there are any deviations from the specifications.

I said okay, that takes care of the quality control part of your job, but what about quality assurance?

He was not aware of his quality assurance responsibilities.

它经常发生,专业人士的工作QA or QC or QA/QC engineer are not aware of their job responsibilities, even though the difference between the responsibilities of quality assurance and quality control functions is clear.

这个问题在中小型组织中普遍存在,在中小型组织中,他们通常没有资源分别聘用质量保证和质量管理工程师。b0b体育app

In such cases, the person may possess the title of QA while working as QC and sometimes QC working as QA, or maybe even worse. This ambiguity is not right for the project and may affect the quality of the deliverable as well as the success of the project.

Quality assurance is the process of managing the quality of the product. Quality control is used to verify the correctness and quality of the product.Before we start discussing quality assurance and quality control in detail, we have first to understand the term “quality.”

What is Quality?

The most important and accepted definition of quality is given by Mr. Philip B. Crosby which says quality is “Conformance to requirements.”

According to ISO 8402:1996 – Quality Management and Quality Assurance Vocabulary standard, “Quality is the totality of features and characteristics of a product or service that bears on its ability to satisfy stated or implied needs.”

According to ISO 9000:2000 – Set of International Quality Standards and Guidelines for Quality Management Systems, “Quality is the degree to which a set of inherent (existing) characteristics fulfills requirements.”

Simply put, you can say that “quality” is about meeting the customer’s requirements and that the deliverable being fit for use.

如果一个产品达到或超过客户的requirements, it is said to be of high quality. However, if it does not meet its stated requirements, the product is of low quality. Please note that, regardless of thegrade, the quality should be high; quality cannot be compromised in any case.

Quality Assurance

quality assurance

The meaning of assurance is surety or trust. Assurance is an act of providing confidence that you can believe in. You can say that quality assurance guarantees the quality of the product. It ensures that the output of the process is defect free and conforms to all requirements.

质量保证是一种基于过程的方法;它的主要目的是防止在计划阶段的可交付成果中的缺陷,以避免返工,这总是昂贵的。

这是一个积极主动的过程;它强调planning, documenting, and finalizing the guidelines that will be necessary to assure the quality. It helps to understand the product’s requirements and expectations, and this process starts at the beginning of the project.

一旦确定了所有要求和期望,就制定了计划以满足这些要求和期望。

Tools Used in the Quality Assurance Process

The following tools are used in quality management: quality audit, process analysis, quality management, and control tools.

In a quality audit, a team of external experts comes in to review the process and procedures. If there are any discrepancies, they will suggest corrective action, and they may suggest an improvement in the process.

Quality audit is a great tool to ensure that the project follows best practices and approved procedures.

In process analysis, you analyze to find any improvements, discover the root cause of any problems and identify any non-value-added activities.

Quality management and control tools include various diagrammatic techniques, which help you find ideas, make decisions, and prioritize issues. A few examples of these tools include an affinity diagram, a tree diagram, network diagram, etc.

质量控制

质量控制

Quality control is a product-based approach that concerns the activities and techniques that are used to fulfill the quality requirements.

质量控制功能正从项目工作开始时开始;这是一种反应性方法,有助于在可交付成果中找到缺陷。质量控制过程的主要目的是确保可交付成果自由和可接受,并根据质量要求。

The quality control process has the following objectives: to find any defects in the product, correct them, and validate the deliverable.

质量保证和质量控制彼此取决于彼此;质量控制过程从质量保证过程中获得输入,进而将其反馈给质量保证过程,以便质量保证过程可以验证运营过程。

For instance, if the project team finds a defect during the execution, they will correct it, and they will send the feedback to the quality assurance team. The quality assurance team will take corrective or preventive action after investigating the cause of this defect to prevent this defect from happening again in the future.

Once the process is updated, the quality control people will follow the updated process so the defect does not recur.

The quality assurance process takes inputs from the quality control process, and vice versa.

Tools Used in the Quality Control Process

Generally, there are three techniques for the quality control process. They are inspection, statistical sampling, and the seven basic tools of quality.

In an inspection, the deliverable is physically examined for any defects and to check if it matches the requirements.

In statistical sampling, you select a random number of items from a batch and inspect them for any defects and conformance.

The seven basic tools of quality arescatter diagram,,,,control chart,,,,histogram, checklist,Pareto diagram,,,,cause-and-effect analysis,,,,and flowchart. These tools help find defects and the causes of defects.

The Difference Between Quality Assurance and Quality Control

The following are a few differences between the quality assurance and quality control processes:

  • Quality assurance focuses on defect prevention, while quality control focuses on defect identification.
  • 质量保证可以确保该计划有效避免任何预期的缺陷。质量控制可帮助您在可交付的情况下找到缺陷并​​纠正它们。
  • Quality assurance is a proactive process which starts even before the work on the deliverable has started, while quality control is a reactive process and its activity starts as soon as you start working on the deliverable.
  • 质量保证是一种基于过程的方法;here you develop the process to create the product, while quality control is a product-based approach where you make sure the product is as per requirements.
  • 质量保证涉及管理质量的流程,质量控制用于验证产品的质量。
  • A quality audit is an example of quality assurance while inspection and testing are examples of the quality control process.

Although these processes are different, they complement each other and the output of one is an input of the other.

The Benefits of Quality Assurance and Quality Control

The following are a few benefits of these processes:

  • 它们为您提供高质量的产出并消除浪费。
  • They increase the efficiency of operations.
  • They provide customer satisfaction, which helps your brand and helps in growing your business.
  • 需要更少的返工和售后支持,这将有助于您节省很多钱。
  • They encourage a high level of confidence and a motivated team.

Quality assurance and quality control are closely related, and they have the same objective, i.e., to deliver a defect-free product.

Both processes are an integral part of a quality management plan and failure to apply either of them will result in a low quality product.

Summary

The quality assurance and quality control processes ensure that a product is defect-free and conforms to requirements. Both processes have the same purpose but, the approach is different. Quality assurance is a process-based and quality control is a product-based. Quality assurance designs a process so that the product created by this process is defect free, while quality control checks the product when producing it to prevent a defective product from reaching the market.

这些过程在您的项目的成功中起着重要的作用。只有在组织和执行工作的团队对他们充分理解的情况下,才能实现它们的有效性。

There is another process, “validate scope,” which might be combined with quality assurance and quality control. I have written another blog post to explain this as well. Please visit:质量控制and Validate Scope

Are you involved in quality assurance or quality control activities? If yes, please share your experiences in the comment section.

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Speak Your Mind

  • Very usefull, with relevent to construction sector , which is not orgnised as manufacturing we are sometimes facing non availability of competent QA /QC professional .
    请提供与建筑有关的详细信息。

  • This is a very interesting and insightful write up. What I would have liked to see further is how a quality management person can apply QA and QC in an organization with diversified products and services. For example printing division and insurance division?

    Does one need to first understand the processestate express undertaking a quality audit of quality control exercise?

    • 你好凯姆法,

      Both processes are interconnected. It would be better for someone if they understood both processes.

  • Thanks so much. I really appreciate what I have learnt on this blog and above the simplicity and relatableness of the instances. Once, thanks a lot

  • 嗨,法哈德,,,,

    You are doing a great job, thanks a lot for this blog! Really helps to understand many concepts in different words (even more clear than in RITA book while, of course, the one should read RITA before the exam).

    A simple acknowledgment of the fact that quality assurance is a process-based approach while quality control is a product based approach (and therefore we apply the same for audits and inspections) allowed to me answer easily to at least 4 or 5 questions during the PMP exam yesterday.

    Thanks,
    Dima

  • Hello Fahad,

    Can we say that QA is the Manage Quality in Project Quality Management and QC is the control quality in Project Quality Management?

    谢谢你,
    Mehul Parekh

  • I have a research assignment which I have to do. From what I have just read, could one formulate a research title which reads:

    Title:Study on the effectiveness of QA vs QC in a Manufacturing Environment.

    Under financial constraints, which of the two would be a better option to invest in. Where one’s aim/objective would be to prove that QA provides a better means of ensuring quality? Or coming to a holistic conclusion that both QA and QC is equally important. I am still quite unsure, this is only the beginning of my research task.

    • Both are equally important and complement each other. In QA you define procedure and in QC you ensure that it is followed.

  • Quality is the satisfaction of the users by fulfilling and/or fully functioning its purpose under specific standards.

  • quality is a word with several meaning and connotation. quality can mean excellence as in,this is a quality product.

  • Have been struggling to understand this concept of how in reality these 2 tasks are performed. Your blog helped me in clarifying the difference and their uniqueness. Very well drafted with common and simple language. Thank you!

  • well,Here are sharing such a good or informative content about Quality Assurance Training.Thanks for the publish great ideas in this blog!

  • Well, here are sharing such a great and helpful information regarding Quality Assurance (QA). Thanks for the publish great ideas in this blog!

  • 我工作道路CONSRUCTION监督ambiguities on both QA and QC. You really solved my confusions. Now both of them are clear for me.
    God bless you so much.

  • As you said ,”In quality assurance, you plan to avoid the defect in the planning phase. In quality control, you try to find defects and correct them while making the product.”. Pmbook says quality assurance is execution process

    • In quality assurance, during the execution phase you check that if the project team is following your plans and procedure correctly.

      The statement is corrected.

  • Sir you said that in quality assurance we plan for processes, how can we say that quality assurance is an execution process

  • If Risk Audit is done in the Controlling group, why is Quality Audit done in Executing?

    我下周参加考试,感谢您的博客!

    • Quality audit it a quality assurance function not quality control, that is why it is performed in execution phase.

      • Fahad,

        Could you please contras Risk Audit with Quality Audit? I understand “audit” to be more of an inspection, or a reactive task compared to a proactive task. Thus I would assume all audits to be in the control process group.

        Thank you!

    • Fahad,

      在从电子书中处理了您的示例问题之后,我意识到采购审核是在Close Procuroments组中,因此现在有三个不同组的审计活动。我现在了解,但是也许对不同类型的审核的讨论可能会有所帮助。

      Thanks again!

  • 嗨,法哈德

    Really like your clear and relevant article on quality assurance.

    Quality assurance might be compared to the direct and manage process of quality control.

  • 嗨,法哈德,,,,

    Thanks for this well-written article, it’s straight-forward and easier to grasp the key differences than PMBOK. Your website is a great tool for me in preparing PMP exam.

  • i am looking for an affordable online courses on Quality management, six sigma or any other related courses. kindly provide links.

  • I am reading all your PMP Certification Exam Study Notes and they are very useful and clear. I am preparing to take the exam in about 2 months, I will read every note but if you have more tips, I would really appreciate them!

    Thanks for help us!

    Pura vida (I am from Costa Rica)

    • You are welcome William.

      You can download my free eBook on A2z on PMP exam and go through it. This book will help you in preparing the exam.

      Let me know if you have any specific question.

  • Wow! I just have to say how impressed I am with the way you explain the differences clearly and easily.
    I am so grateful for stumbling upon your blog before my exam in 3 days! Thank you!

  • Hello Fahad,

    使用任何质量管理和控制质量过程工具的质量检查过程。

    My query is : whether Quality Assurance process is using 7 basic quality tools(any of 7) ?

    • These processes are interdependent on each other, so they may use any tool depending on the situation.

  • Assalaamu alaikkum Fahad,
    我刚刚加入了一家IT公司,担任QA工程师。该公司开发了其中一所大学所需的网站。到目前为止,还没有质量检查部门。作为质量保证工程师,我应该在这里介绍什么过程。

    Thanks and Regards
    Basheer

    • Wa-Assalam Basheer,

      First of all you should check all procedures. There must be some procedures. Go and review those procedures, and check if they are following these procedures.

  • 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.

    • Hello Daleep,

      Good Luck for your exam.

      希望一旦您通过考试,才能再次在这里见到您。

  • 嗨,法哈德,,,,
    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 :)

    Regards,
    Prasanna Kumar K R,PMP

  • 嗨,法哈德,,,,

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

    这个博客很棒,解释很好!

    Thank you very much!

    Regards,
    Abhilash VJ

    • Hi Abhilash vj

      Iam glad to see you comments on qa and qc. Its clear understand that qa works of to see that the product is defect free.While qc is working to make sure the product to produced is to free defect according to the custome requests.
      Lastly have liked what you are doing oil and gas quality engineer.

      Regards

  • Help me to answer this question …..?

    乔是一个项目经理在一个工业设计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.执行质量保证

    C. Perform Quality Control

    D. Qualitative Risk Analysis

    I found that answer is B, but why ?….In PMBOK, under Quality Control (8.3.2.1) cause and effect daigram’s are explained …..so doesn’t it fall under Quality control …?

    Thanks in advance.

    • 看看乔在做什么。他仅审查公司使用的流程,以便可以删除(在过去的项目中发生)的缺陷。这是质量保证的工作,以避免任何缺陷来开发过程。

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

      Therefore, the answer B is correct.

  • Fahad,

    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.

    谢谢。

  • Fahad,

    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.

    • 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.

  • 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.
    Regards
    Saleem Angillath

    • 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.

      Fahad

  • 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.

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