Process failure modes and effects analysis

Process Failure Modes and Effects Analysis (PFMEA) Training

November 2003

PFMEA Training
1.0 What is a PFMEA? l A Process Failure Modes and Effects Analysis provides a structured, qualitative, analytical framework which taps the multi-disciplined experience of the team to brainstorm answers to such questions as:
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How can this process, function, facility, or tooling fail? Whateffect will process, function, facility, or tooling failures have on the end product (or customer)? How can potential failures be eliminated or controlled?

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Based on the success of Failure Modes and Effects Analysis (FMEA), the PFMEA concept was developed to incorporate a broader analysis team to accomplish a thorough analysis in a short time A PFMEA can be used to assess any process. The mostcommon use of the PFMEA involves manufacturing processes
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PFMEAs may be performed on new processes or to improve current processes To maximize its value, a PFMEA should be performed as early in the manufacturing development cycle as possible

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PFMEA Training
1.0 What is a PFMEA? (cont)
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Because most PFMEAs involve manufacturing area processes, the manufacturing engineeris usually the team leader
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The effectiveness of the team depends upon the expertise of its members, and the quality of the team output depends on the willingness of each team member to give his or her best effort Teams may include:
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Manufacturing Engineer Design Engineer Tooling Engineer System Safety Engineer Industrial Engineer Handling Specialist LineForeman/Operators Customer Materials & Process Engineer Others as required

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PFMEA Training
2.0 How to Conduct an Effective PFMEA l Prior to the first meeting, the team leader should
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Establish objectives and scope Choose experts for the PFMEA team

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The team leader is responsible for the effectiveness of the review
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Brainstorming used to increase creativity and bring out awide range of ideas Discussion allows team to look at things from different view points A visit(s) to the work area with an overview of the process/ test/ operation gives team members basic understanding of the process Limit meetings to one hour

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PFMEA Training
2.0 How to Conduct an Effective PFMEA (cont)
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STEP 1
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Team leader organizes the team; defines the goals, methods,scope, responsibilities of each team member; and establishes a tentative schedule After reviewing engineering, drawings, and planning, team develops a flow chart showing the major functions or operations of the process to help team members understand the process

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STEP 2
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For each process function, team determines all credible failure modes Team discusses and records the failureeffects, failure causes, and current controls for each potential failure mode Team rates occurrence, severity, and detection for each failure cause
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It is helpful to rate all failure causes for occurrence first, next rate for severity, and then rate for detection The Risk Priority Number (RPN) is the product of these ratings

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PFMEA Training
2.0 How to Conduct an Effective PFMEA(cont)
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STEP 3
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Identify corrective action to improve the process/test
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Failure causes with the highest RPN should be analyzed first
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High occurrence number indicates the causes should be eliminated or controlled High detection number indicates a need for additional controls High severity number indicates product or process redesign may be needed

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Conduct additionalbrainstorming to develop effective and innovative ways to reduce failure
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Proposed changes identified as “Resulting Action Taken” and new occurrence, severity, detection, and RPN ratings are assigned

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PFMEA Training
2.0 How to Conduct an Effective PFMEA (cont)
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STEP 4
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Proposed changes for high/significant RPN ratings that have not been completed are listed on the PFMEA form...