Quality Assurance vs Quality Control

2020年7月26日
法哈德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.

Since these processes are connected and work in coordination, many professionals, especially those working in small and medium sized organizations, do not understand their differences.

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?

他不知道自己的质量保证责任。

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.

This issue is prevalent in small or medium-sized organizations where they usually do not have the resources to hire QA and QC engineers separately.

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?

菲利普·B·克罗斯比(Philip B.

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.

如果产品满足或超过客户的要求,则据说它具有高质量。但是,如果它不符合其既定要求,则该产品的质量低。请注意,不管grade, 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.

Quality assurance is a process-based approach; its primary objective is to prevent defects in deliverables in the planning stage to avoid rework, which is always expensive.

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.

Once all requirements and expectations are identified, a plan is developed to meet these requirements and expectations.

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.

Quality Control

quality control

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

Quality control functions start right at the beginning of the project work; it is a reactive approach, which helps find defects in deliverables. The primary objective of the quality control process is to make sure that the deliverables are defect free and acceptable and based on the quality requirements.

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

Quality assurance and quality control are dependent on each other; the quality control process receives input from the quality assurance process, and in turn, gives its feedback to the quality assurance process so that the quality assurance process can validate the operational process.

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.

质量保证过程从质量控制过程中获得输入,反之亦然。

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.

质量保证与质量控制之间的区别

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

  • 质量保证侧重于预防缺陷,而质量控制则侧重于缺陷识别。
  • Quality assurance guarantees that the plan was efficient to avoid any anticipated defects. Quality control helps you find defects in the deliverable and correct them.
  • 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.
  • Quality assurance is a process-based approach; 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.
  • Quality assurance involves processes managing quality, and quality control is used to verify the quality of the product.
  • 质量审核是质量保证的一个示例,同时检查和测试是质量控制过程的示例。

尽管这些过程是不同的,但它们相互补充,一个输出是另一个输入。

质量保证和质量控制的好处

The following are a few benefits of these processes:

  • They provide you with high-quality output and eliminate waste.
  • They increase the efficiency of operations.
  • 他们提供客户满意度,这有助于您的品牌并有助于发展业务。
  • Less rework and after-sale support are required, which will help you save a lot of money.
  • They encourage a high level of confidence and a motivated team.

质量保证和质量控制密切相关,并且具有相同的目标,即提供无缺陷的产品。

这两个过程都是质量管理计划不可或缺的一部分,并且未能应用任何一个都将导致低质量的产品。

Summary

质量保证和质量控制过程确保产品没有缺陷并符合要求。这两个过程都有相同的目的,但是方法是不同的。质量保证是一种基于过程的,质量控制是基于产品的。质量保证设计一个过程,以使该过程创建的产品无缺陷,而质量控制则在生产产品时检查该产品以防止有缺陷的产品进入市场。

These processes play essential roles in the success of your project. Their effectiveness can only be achieved if they are well understood by the organization and the team performing the job.

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:Quality Control 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 .
    Please give in details related to construction.

  • 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?

    • Hello Kaimfa,

      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

  • Hi Fahad,

    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?

    Thank you,
    Mehul Parekh

  • 我有一个研究任务,我必须做。从我刚刚阅读的内容来看,一个人可以制定一个研究标题,该标题读到:

    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

  • Thx. This post is indeed informative and crystal clear. Exactly what I needed as I start my journey as a quality assurer

  • 如果在控制组中进行了风险审核,为什么执行质量审核?

    I am taking the exam next week, thanks for your blogs!

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

      • 法哈德,

        您能否与质量审核进行反对风险审核?与主动任务相比,我理解“审核”更多是检查或反应性任务。因此,我认为所有审核都位于控制过程组中。

        Thank you!

    • 法哈德,

      After working on your sample questions from your eBook, I realize Procurement Audit is in the Close Procurements group, so now there is an audit activity in three different groups. I understand now, but maybe a discussion on the different types of audits might be helpful.

      Thanks again!

  • Hi Fahad

    Really like your clear and relevant article on quality assurance.

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

  • Hi Fahad,

    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(我来自哥斯达黎加)

    • You are welcome William.

      您可以在PMP考试上下载我的A2Z上的免费电子书,然后仔细阅读。这本书将帮助您准备考试。

      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,

    QA process using any tool of Quality management and control quality process.

    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,
    I just joined in one of the IT company as QA Engineer. The company develops website required for one of the university. There is no QA department as of now. As QA Engineer what are the process that i should introduce here.

    感谢致敬
    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.

  • 在接下来的2天内参加考试…。我必须说,您的文章和博客确实在帮助感谢您的出色工作!

  • Hi Fahad,
    只是想说通过在博客中提供明确的信息来说出您正在做的超级工作。我昨天刚刚了解了这个网站,这是我的考试前一天……我花了大约2 - 3个小时阅读了您的所有文章,这使Crystal Crystal变得清晰了,我今天通过了PMP。保持了出色的工作 :)

    Regards,
    Prasanna Kumar K R, PMP

  • Hi Fahad,

    我是石油和天然气行业的招聘顾问。

    This blog is fantastic and very well explained!!

    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

  • 帮我回答这个问题…..?

    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. Perform Quality Assurance

    C.执行质量控制

    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.

    • 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.

      在质量控制过程中,项目经理采集样本或随机检查运行项目中的过程。

      Therefore, the answer B is correct.

  • 法哈德,

    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.

    Thanks.

  • 法哈德,

    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,

      您的理解是正确的。

      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
    我第一次尝试通过了PMP。您的博客在准备考试方面有很大帮助。非常感谢。对于所有PMP有抱负的人和对PM感兴趣的其他人来说,您的博客是一个杰出的博客,非常有用。写得很好且内容丰富。我仍然关注您的博客,以获取有关PMP的最新文章。一切顺利,并期望您更多。
    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.

      法哈德

    • Thanks Fahad,
      I can imagine that I can apply QA without QC, but I cannot imagine to apply QC without QA. What can I check or inspect if it’s not defined well ( which is a QA step) ?

      • Hello Sameh. both processes complement each other.

        I did not understand your question well. Please elaborate.

  • 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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