质量保证与质量控制(QA与QC)

质量保证与质量控制

Quality Assurance (QA) and Quality Control (QC) are the processes most vital for a project’s success. However, professionals often confuse and intermingle the two.

Allow me to clarify the concepts. After reading this Quality Assurance Vs Quality Control (QA vs QC) blog post, I hope you will have a better understanding of the quality assurance and quality management processes.

Every project has QC and QA functions. The QC section communicates and coordinates with the QA department and the organization.

Since these processes work closely together, many professionals, especially those working in small and medium-sized organizations, do not understand the differences.

I met with many professionals involved in quality management during my ISO 9001 training course a few years back. These people had different backgrounds and were working across various fields.

One man told me he was working as a QA/QC engineer in his company, and I questioned him about his responsibilities and duties.

He replied that he goes around checking that the work is going as planned. He inspects deliverables with specifications and recommendscorrective actionif the deliverable has deviation or the process is out of control.

I then asked him about the quality assurance part of his job. He gave me the same response.

This told me he was not aware of his quality assurance responsibilities.

Often QA or QC or QA/QC engineers are not aware of their job responsibilities, especially in small organizations, because the differences can be so murky.

Sometimes, they don’t know the meaning of QA or QC.

This issue is prevalent in small or medium-sized organizations, where there are rarely the resources to hire both QA and QC engineers.

In such cases, the employee may possess the title of QA while working in QC and sometimes QC working as QA. Or their responsibilities and duties may be even more scrambled.

This ambiguity needs to be corrected because it does affect the quality of the deliverable and the success of the project.

Quality Assurance Vs Quality Control (QA vs QC)

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 discuss the differences between these concepts in detail, we have first to understand the term “quality.”

The most important and accepted definition is from Mr. Philip B. Crosby, who says simply that quality is “Conformance to requirements.”

根据ISO 8402:1996 - 质量管理和质量保证词汇标准,“质量是产品或服务的全部特征和特征,它具有满足既定或暗示需求的能力。”

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, “quality” is about meeting the customer’s requirements to see if the deliverable is fit for use.

If a product meets or exceeds the customer’s requirements, it is said to be of high quality. It is of low quality if it does not.
Please note that, regardless of the product’sgrade, the quality should be high; you cannot compromise with quality for any reason.

Quality Assurance (QA)

quality assurance

Assurance is an act of providing confidence that the customer can believe in.

QA guarantees the quality of the product, by ensuring that the output of the process is defect-free and conforms to all requirements.

Quality assurance is a process-based approach with the objective of preventing defects in deliverables while in the planning stage to avoid expensive reworks.

QA is a proactive process; it emphasizes planning, documenting, and finalizing guidelines. This helps communicate the product’s requirements and starts at the beginning of the project.

确定要求后,您将制定质量管理计划,以满足利益相关者的要求和期望。

Tools Used in the Quality Assurance Process

The following tools are used in quality management:

  • Quality audits
  • Process analysis
  • Quality management tools.

质量审计,外部专家牧师的一个团队iews the process and procedures. If there are any discrepancies, they will suggest corrective action, and they may offer advice on improving the process.

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

In the process analysis, you analyze for 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 include an affinity diagram, a tree diagram, anetwork diagram, etc.

Quality Control (QC)

quality control

Quality control (QC) is a product-based approach that includes the activities and techniques for fulfilling quality requirements.

从头开始啊,质量控制功能f the project. This is a reactive approach that helps find defects in deliverables. The objective of the QC process is to ensure the deliverables are defect-free and fulfill quality requirements.

The quality control process has the following objectives: finding any defects in the product, correcting them, and validating the deliverable.

QA and QC depend on each other; the quality control process receives input from the quality assurance process and provides feedback to the quality assurance process so that the quality assurance personal can validate the process.

For instance, say the project team finds a defect during execution. They will correct it, and they will send the feedback to the quality assurance team.

This team will investigate the cause of the error and take action to ensure that it does not occur again.

After the process update, the quality control people will follow the updated process to stop the defect occurrence.

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

Tools Used in the Quality Control Process

The quality control process has three main techniques:

  • Inspection
  • Statistical sampling
  • The seven basic tools of quality

During an inspection, the deliverable is physically examined for any defects and to check it against the quality requirements.

A statistical sampling selects a random number of items from a batch to inspect them for any defects and conformance.

The seven basic tools of quality are:scatter diagrams,控制图, histograms, checklists,Pareto diagrams,cause-and-effect analyses, and flowcharts. These tools help find defects and the causes of defects.

The Differences Between Quality Assurance and Quality Control

Quality Assurance Quality Control
Defect prevention Defect identification
避免可交付的缺陷 Corrects defects in the deliverable
A proactive process A reactive process
Process-based approach Product-based approach
Quality managing processes Quality verification
A quality audit is an example tool A quality inspection is an example tool

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

The Benefits of Quality Assurance and Quality Control Processes

  • High-quality output and eliminate waste.
  • Increased efficiency of operations.
  • Greater customer satisfaction, which helps your brand and grows your business.
  • Lessen rework and after-sale support are required, which saves a lot of money.
  • Encourages a high level of confidence and motivates the team.

Quality assurance and quality control are closely related; they both aim 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 have the same purpose but use different approaches. Quality assurance is process-based, and quality control is product-based. Quality assurance designs a process to create a defect-free product In contrast, quality control prevents a defective product from reaching the market.

These processes play essential roles in the success of your project. They can only be achieved effectively if the team and the organization understand their significance.

Another process, “validate scope,” might be combined with quality assurance and quality control. I have written a blog post to explain this as well.

Please visit:Quality Control and Validate Scope.

Here is where this post on QA vs QC ends.

Are you involved in quality assurance or quality control activities? Please share your experiences in the comment section.


  • 非常有用,与建筑领域有关,这并未被认为是制造业,我们有时面临着胜任的QA /QC专业人员的可用性。
    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?

  • 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,

    您做得很好,非常感谢此博客!确实有助于用不同的单词理解许多概念(甚至比Rita Book中更清晰,而当然,应该在考试前阅读丽塔)。

    一个简单的认可,即质量保证是一种基于过程的方法,而质量控制是一种基于产品的方法(因此,我们适用于审核和检查),可以轻松地回答PMP期间至少4或5个问题昨天考试。

    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

  • 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.

  • 一直在努力理解这个概念的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!

  • I am working on road CONSRUCTION supervision with ambiguities on both QA and QC. You really solved my confusions. Now both of them are clear for me.
    God bless you so much.

  • 正如您所说,“在质量保证方面,您计划避免在计划阶段的缺陷。在质量控制中,您尝试在制造产品时找到缺陷并​​纠正它们。”。PMBOOK说质量保证是执行过程

    • 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

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

    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.

      • Fahad,

        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!

    • Fahad,

      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.

  • 我正在寻找有关质量管理,六个Sigma或任何其他相关课程的负担得起的在线课程。请提供链接。

  • 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)

    • 不客气威廉。

      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!

  • 谢谢法哈德。出色的解释……不仅是这个,而且是所有博客文章……非常感谢。

  • 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) ?

  • 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.

    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.

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

  • 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,

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

    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

  • 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 (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.

  • Fahad,

    非常感谢您的回复。这清除了我的疑问。

    您对参加在线培训的建议是什么?现在,我自己做准备,不知道我是否朝着正确的方向发展。您可以提出的任何建议将不胜感激。

    Thanks.

  • Fahad,

    我确实觉得您的文章很好。由于某种原因,我无法理解这篇文章。你能帮我么?

    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.

    • 你好,拉文德拉,

      Your understanding is correct.

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

      在质量控制期间,如果您发现某些过程需要一些改进或造成任何麻烦,那么您可以提供质量保证的反馈,以改善程序,因此可以投入质量保证。

  • 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!

      我希望该认证能够帮助您发展职业。感谢您在PMSC分享您的幸福。

      保持联系。

      Fahad

    • Thanks Fahad,
      我可以想象我可以在没有QC的情况下应用QA,但是我无法想象没有QA可以应用QC。我可以检查或检查它的定义不当(哪个是质量检查步骤)?

      • Hello Sameh. both processes complement each other.

        I did not understand your question well. Please elaborate.

  • 感谢您发布博客,分享您的见解以及井井有条的想法和解释。我希望我在旅行中遇到您的博客,因为今天我第一次尝试通过PMP考试。我准备不足,通过互联网网站过于依赖自学,当人们试图挖洞和研究其中时,生活经常发生……生活总是会让您摆脱所有学习乐趣。Anyhoo,喜欢您的写作风格,它并不是太过学费,并且不是PMBOK中发现的,这对我来说是读书的恐惧。我从来没有花时间在两者之间真正辨别,今天困扰着我。

  • {"email":"Email address invalid","url":"Website address invalid","required":"Required field missing"}

    Recommended Resources

    Use these resources for your PMP certification exam preparation and pass the exam with minimal effort.

    The PMP Training Program


    The PMI approved 35 contact hours training program that is 100% online, affordable, and help you prepare the PMP exam.

    The PMP Exam Preparation Tool


    A PMP exam preparation course, that is 100% online and provide you everything you need to pass the PMP exam.

    >