DIAGNOSIS OF “7-Step Approach” of FMEA: As per first edition of FMEA HANDBOOK

The most important part is execution of FMEA and same is based on “7-Step Approach”, the steps are:

1. Step 1:Planning & Preparation,
2. Step 2:Structure Analysis,
3. Step 3:Function Analysis,
4. Step 4:Failure Analysis,
5. Step 5:Risk Analysis,
6. Step 6:Optimization, and
7. Step 7: Results Documentation.

The above seven steps approach is categorised into three phases and are System Analysis, Failure Analysis and Risk Mitigation Risk Communication

Phase 1: “System Analysis” phase represent, Steps 1 through 3.

Phase 2: “Failure Analysis and Risk Mitigation” phase represent, Steps 4 through 6.

Phase3: “Risk Communication” phase is Step 7, Results Documentation.

Phase 1: “System Analysis” phase represent, Steps 1 through 3

Step 1: Planning & Preparation

1. Start DFMEA / PFMEA with identification of project and fix the boundaries and scope for the identified project.
2. The identified project to be planned as per methodology of 5T and they are InTent, Timing, Team, Task and Tools.
3. The focus to be given or details to be gathered and summarized, so that, this will helpful in step 2, Structure analysis.

Step 2: Structure Analysis

1. In Design FMEA, structure analysis is use to identify and breakdown the FMEA scope into System, Subsystem and components parts for technical risk analysis.
2. In Process FMEA, structure analysis is use to identify and breakdown the FMEA scope of manufacturing system into Process items, Process Steps and Process work elements.
3. In Design FMEA and in Process FMEA, output of structural analysis provides a tool for collaboration between customer and supplier during technical review.
4. In Process FMEA, process flow diagram can be used as input to structural analysis as a tool.

Step 3: Function Analysis

1. In Design FMEA, function analysis, the functions as per requirement and or as per specification to be taken care for each system.
2. In Process FMEA, function analysis, the function is to describe process items and process steps and in analysis.

Failure analysis is useful in finding, Failure Effect (FE), which is nothing but negative function of process, which can comes out by listing the positive function of function.

Also, in function analysis, function of the process, function of system, Subsystem, Part Element or process are to be added.

Phase 2: “Failure Analysis and Risk Mitigation” phase represent, Steps 4 through 6.

Step 4: Failure Analysis

1. As from the name Failure Analysis, this include failure causes, failure mode and failure effect.
2. This is nothing but creation of Failure Chain.
3. The process failure causes can be found with use of fishbone diagram (4M) or failure network.
4.  The 4 M of fishbone diagram are, Man, Machine, Material and Environment.

Step 5: Risk Analysis

1. Evaluate Severity, Occurrence and Detection to estimate risk.
2. Rating to be given to Severity, Occurrence and Detection.
3. Action priority to be evaluated base on Severity, Occurrence and Detection.
4. Here, RPN (Risk Priority Number) which use in earlier version has been replaced with Action priority (AP).
5. Action priority (AP), account for all 1000 possible combination of S, O and D.
6. Action priority (AP) is created and introduced to give more emphasis on Severity first, then Occurrence and then Detection.

Step 6: Optimization

1. The basic and foremost objective of optimization step is to identify and select the action necessary to reduce risk.
2. The action should improve the process at same time shall not reduce assessment rating.
3. During the analysis, effectiveness of action taken should be check.

Phase3: “Risk Communication” phase is Step 7, Results Documentation.

Step 7: Results Documentation

1. The result of FMEA shall be documented with conclusion and analysis.