A Brief Discussion on the Five Core Tools of IATF 16949 and Their Interrelationships

I. APQP (Advanced Product Quality Planning)

APQP emphasizes the management of product design and manufacturing process design through methods such as product quality advance planning or project management before mass production, in order to determine and formulate the steps required to make the product meet customer satisfaction. The objective of product quality planning is to ensure product quality and enhance product reliability. It is generally divided into the following five stages:

Phase One: Plan and determine the project (project phase);

Phase Two: Product design, development and verification (design and prototype vehicle trial production)

Phase Three: Process design, development and verification (trial production stage)

Phase Four: Product and process Validation (Mass production phase)

Phase Five: Feedback, Evaluation and Corrective Actions (after mass production).

Ii. FMEA (Failure Mode and Effects Analysis)

FMEA embodies the idea of error prevention. It requires that in the design stage and process design stage, each subsystem, component and process that constitutes the product be analyzed one by one to identify all potential failure modes and analyze their possible consequences, so as to take necessary measures in advance to improve the quality and reliability of the product. It is a systematic activity.

FMEA analyzes failure modes from three aspects: severity (S), frequency (O), and detection (D), and concludes that the risk sequence number RPN=S×O× D. Necessary preventive measures are taken for RPN and failure modes with higher severity. FMEA can eliminate or reduce the chances of potential failures and is recognized by the automotive industry as the most effective quality prevention tool for reducing "recall" incidents.

Iii. MSA (Measurement System Analysis)

MSA is a method that uses mathematical statistics and graphical approaches to analyze the resolution and error of a measurement system, in order to assess whether the resolution and error of the measurement system are appropriate for the parameters being measured and to determine the main components of the measurement system's error.

The error of a measurement system is characterized by the bias and variance of the statistical characteristics of multiple measurement data for a measurement system operating under stable conditions. Generally speaking, the resolution of a measurement system should be one-tenth of the process variation in obtaining the measurement parameters. Relevant indicators of a measurement system include: repeatability, reproducibility, linearity, bias and stability, etc.

Iv. PPAP (Production Part Approval Procedure)

PPAP refers to providing samples and necessary materials to the customer for approval and verification before mass production of the product to determine whether the customer's design requirements and specifications have been correctly understood.

The situations that require PPAP include new products, sample corrections, design changes, specification changes, and material changes, etc. The provided documents can include the following aspects: samples, design records, process flow diagrams, control plans, FEMA, dimensional results, material/performance tests, quality indices, guarantee letters (PSW), appearance approval reports (AAR), and 19 other items. Only after PPAP approval can bulk supply be provided to customers.

In PPAP, the submitted documents are divided into five levels. In the automotive industry, level 3 is the default submission level. The submitted documents include guarantee letters, product samples, and complete supporting data, etc.

V. SPC (Statistical Process Control)

SPC embodies the idea of preventing and reducing deterioration. It refers to the application of statistical analysis techniques to monitor the production process in real time, scientifically distinguish between random fluctuations and abnormal fluctuations in product quality during the production process, and issue early warnings for abnormal trends in the production process, so that production managers can take timely measures to eliminate abnormalities and restore process stability. So as to achieve the purpose of improving and controlling quality.

The tool used in SPC is the control chart. The control chart is a quality tool that determines whether the process is abnormal by measuring the main characteristic values in the production process, marking points in a time series, and evaluating the position and trend of the monitoring characteristics in the control chart.

The five major quality tools are at the core of IATF 16949 and have been proven to be applicable to the automotive industry. They will play a significant role in enhancing the quality management level and competitiveness of the automotive industry.

The relationship among the five major tools

This topic is bound to be unclear to those who have not practiced it. Even those who have practiced it may not be able to figure it out because of their interweaving. Ford spent a hundred years drawing the classic APQP network diagram, which shows how much effort he put into it. Here I will give a brief description of the five major tools, hoping to provide everyone with a basic concept.

APQP is a task that parts companies must undertake when providing new products to vehicle manufacturers. It aims to solve all problems before the products go into production. Therefore, it is a complex process and requires several rounds of repetition before it becomes the final planning result.

FMEA is a failure mode analysis conducted during the second and third stages of APQP, covering both products and processes. The most crucial point here is that at this stage, the product has not yet been produced but rather a potential possibility analysis. Many enterprises are not accustomed to this and always analyze it as if it were a product that is already in production.

SPS and MSA are both formed during the process planning process. That is to say, what kind of processes need to be controlled by SPC? Generally speaking, processes with special characteristics should use SPC, but this is not absolute. It should be noted here that the control plan is the result of APQP planning. In this result, measuring tools are inevitably used, and whether these measuring tools can meet the needs of process measurement needs to be analyzed by MSA. Simply put, all the measuring instruments involved in the control plan should undergo MSA, and then in the initial control plan, That is to say, in the control plan for trial production, the planned measuring tools or the selected SPC may not have good results. Therefore, adjustments and improvements may be made, and finally the control plan for formal production will be formed. The SPC and MSA in the formal production control plan should be able to meet the needs of mass production.

Summary

APQP is a quality plan, but in fact, it is also a plan for project development. Since it is a plan, its time starting point is from the moment the project is officially launched until the end of PPAP. After normal mass production, a summary is made and it is believed that there are no other issues, and the development project can be shut down. The executor is the entire APQP team.

PPAP is the production part approval procedure, which is just one stage of the entire APQP plan, usually located in the second half of the APQP plan, and generally speaking, it is the core of the APQP plan. If PPAP fails to obtain the client's approval, the APQP plan is basically doomed to fall through. So when we talk about APQP, we always mention them together: APQP/PPAP. From this, it can be seen how important PPAP is. The main executors are (development, production, and quality) engineers. FMEA, SPC and MSA are all tools for quality management.

As a friend pointed out, FMEA includes DFMEA and PFMEA. The introduction events of these tasks are mostly in the early or middle and early stages of APQP. They mainly refer to the design, production process or procedure of the product. It belongs to a preventive plan.

MSA is very simple. It just involves checking the measurement and measuring tools. Don't view everything as overly complicated.

SPC is also quite simple. It involves controlling several key parameters and supervising the stability of their production. If significant fluctuations are detected, immediate measures should be taken to correct the process or production flow.

Like SPC, it is more appropriate to implement MSA at the PPAP stage (there are many influencing factors that can render MSA ineffective if it is implemented too early, etc.). The implementers are mostly quality engineers. SPC often needs to be implemented throughout the long-term process of formal mass production based on the different requirements of customers.