What Are the Different Methods of Quality Control in Manufacturing?

The quality control method is a quality management method that guarantees product quality and continuously improves product quality. It researches and analyzes the distribution of product quality data, reveals the laws of quality differences, finds out the reasons that affect quality differences, and adopts technical organization measures to eliminate or control the factors that produce defective or unqualified products, so that the product is in the entire process of production Each link in the process can be carried out normally and ideally, and finally the product can reach the natural attributes and characteristics that people need, that is, the applicability, reliability and economy of the product.

Quality control methods

This law was first proposed by Shearhart of the Bell Telephone Research Institute in the United States in 1924, and later developed in 1931 by Dodge and Romig of the same institute to become the founder. It has three characteristics: one is the use of quantitative statistical methods; the second is to focus on the quality control throughout the production process; the third is to widely use various quality data maps. ^[1]

The whole process of using this method to control product quality is divided into the following 3 steps: ^[1]

1. Layered method ^[2]

The result of project quality control is the comprehensive result of the project quality control and quality assurance work, and the comprehensive result of all the work of project quality management. The main contents of this result include the following aspects. ^[3]

1. Measurement results of project quality control

This is a measure of the effect of quality control generated after the end of the project's quality control activities, and the result of this measure is ultimately the acceptance of the quality of the project. Acceptance of project quality has two meanings: one is the acceptance and approval of the completed project results by the project quality control personnel according to the project quality standards; the other is the project owner or user or his agent according to the overall project quality standards Acceptance and approval of the results of completed projects. If people make an unacceptable decision, the quality defects of the project should be repaired to meet the project quality requirements.

2. Recognition of project quality restoration results

Another important result of the project quality control work is the recognition of the project quality restoration work results after the project has quality problems. As mentioned earlier, the project quality implementation results that are not accepted by people need to be repaired. If the results of such project quality repair work cannot be accepted, people need to adjust or reduce the project quality requirements. 3 Adjust or reduce project quality requirements

In the project quality control process, when there is a gap between the actual project quality and the quality benchmark, if this gap is caused by the unreasonable initial project quality requirements, people need to adjust or reduce the project quality requirements. In this case of project management, the adjusted or reduced project quality requirements are also one of the results of project quality control.

4 Preventive, corrective and remedial actions taken

The preventive measures taken in the project quality control are all for the purpose of achieving ex-ante control. This is one of the results of the project quality control. The adopted project quality corrective measures are to restore the project quality. One of the other remedial measures taken when the project quality consequences cannot be corrected is also one of the results of project quality control. In addition, various changes to the project can also be considered as one of the results of project quality control, because the project change is actually the result of the aforementioned preventive, corrective and remedial measures.

5. Updated project information

Various project documents will be updated in the project quality control work, and the results in this regard mainly include the following two aspects.

(1) Checked checklist (checkedlist) This is a result of project quality control work. When people use the checklist to carry out project work quality control, all worklist records that have completed the checkup are project quality control reports. This can be used to provide basis and information for the adjustment and improvement of the quality control of the next project.

(2) Documents of lessons learned There will be some useful lessons in the process of project quality control. After the quality control work is completed, people need to organize them in time and form documents to guide similar projects in the future. This is also a very important content of the project quality control work results.

6. Recognized project deliverables

The fundamental purpose of project quality control is to determine that the deliverables fully meet the project quality requirements in terms of quality. Therefore, the most direct result of project quality control is to obtain a project deliverable that is recognized by various stakeholders in terms of quality. In addition, various updated project plan documents also fall into this category, including updated project integration plans, project specific plans, and project quality management plans and their changes.