What does FMEA mean? Three elements of FMEA failure analysis

Date：2022-03-10 14:04:34Views：2196

Failure mode and effect analysis (FMEA) is one of the five major tools of iatf16949 quality management system.

What is FMEA?

FMEA is failure mode and effect analysis, which means failure mode and effect analysis. It is an analysis method used to determine potential failure modes and their causes. FMEA is a quantitative qualitative analysis and calculation method to analyze the possible (and / or occurred) failure modes and judge the risk degree caused by the possible (and / or generated) consequences, and take targeted improvements according to the risk, so as to understand the product (and / or manufacturing process) design capability, Reach a pre prevention and implement improvement measures.

FMEA common tools

1. Function tree

2. Boundary map

3. Interface matrix

4. Parameter diagram

5. Robust design checklist

6. Design verification list

7. Design verification plan

FMEA six steps

Step 1: define the scope, use the boundary diagram to define the scope, and determine what is included and what is not included.

Step 2: structural analysis, using structural tree diagram and matrix diagram, decompose the system into subsystems, products and parts, and express the relationship between systems, subsystems, products and parts.

Step 3: function analysis, using P diagram, function tree and function matrix to describe the product function to clarify the relationship between "cause and result".

Step 4: failure analysis: use failure analysis table and failure tree to find out the relationship between failure consequences, failure modes and failure causes.

Step 5: risk analysis, using the new RMR risk matrix to clarify the priority of the bank.

Step 6: optimize and clarify the follow-up tracking status.

Three elements of FMEA: quantitative risk assessment, listing causes / mechanisms, and looking for preventive / improvement measures

FMEA starts before product design and manufacturing process development activities, and guides the implementation throughout the whole product cycle. An inductive analysis method that analyzes all possible failure modes of each product in the system and all possible effects on the system, and classifies them according to the severity, detection difficulty and occurrence frequency of each failure mode.

Failure mode analysis at design stage:

1. Based on the designed ideas, review the structure, functional problems and prevention strategies of the system one by one.

2. Review the problem points and preventive strategies of the structure and function of the parts.

3. Review the possible problems among several parts groups or parts groups.

Failure mode analysis at the stage of test plan formulation:

1. Review the selection of test objects and the purpose and method of the test.

2. The effective application of experimental methods and the review of new evaluation methods.

3. Follow up after the test and continuous application of effectiveness.