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 proper纠正措施if 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.

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?

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.”

根据ISO 9000：2000 - 一套国际质量标准和质量管理系统指南，“质量是一组固有（现有）特征满足要求的程度。”

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

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；its primary objective is to prevent defects in deliverables in the planning stage to avoid rework, which is always expensive.

这是一个主动的过程；它强调计划，记录和最终确定确保质量所必需的准则。它有助于了解产品的要求和期望，并且此过程始于项目的开头。

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.

质量审核是确保项目遵循最佳实践和批准程序的绝佳工具。

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

质量控制是一种基于产品的方法，涉及用于满足质量要求的活动和技术。

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.

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.

在检查中，可以对可交付的任何缺陷进行物理检查，并检查它是否符合要求。

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,因果分析, and flowchart. These tools help find defects and the causes of defects.

The Difference Between Quality Assurance and Quality Control

以下是质量保证和质量控制过程之间的一些差异：

• Quality assurance focuses on defect prevention, while quality control focuses on defect identification.
• 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.
• 质量保证是一种基于过程的方法；在这里，您可以开发创建产品的过程，而质量控制是一种基于产品的方法，您可以根据要求确保产品为。
• Quality assurance involves processes managing quality, and quality control is used to verify the quality of the product.
• 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:

• They provide you with high-quality output and eliminate waste.
• They increase the efficiency of operations.
• They provide customer satisfaction, which helps your brand and helps in growing your business.
• 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.

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.

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.