FMEA

FMEA (Failure Mode and Effects Analysis) is an analytical methodology used to ensure that potential problems have been considered and addressed throughout the product and process development cycle. Examples of common development cycles are APQP (Advanced Product Quality Planning), CPPD (Collaborative Product Process Design) and NPI (New Product Introduction).

A DFMEA (Design FMEA) is performed prior to the completion of the design of the product. A PFMEA (Process FMEA) is performed prior to the release of the design for the process. It is critical that a FMEA be performed with sufficient time to take counter measures against the risk and still capture the changes within the design before its release. Quality-One Training and Facilitation is a great way to learn more about how a FMEA works.

Q-1’s facilitated FMEAs are reviewed at various stages of design and updated as actions are completed. Q-1 FMEA Development methods improve the quality of each FMEA, compared to traditional methods, through a 70% reduction in development time. Our Facilitation techniques are the “Best-in-Class”. The primary reason for doing a FMEA is taking action to prevent a failure, improve design control through testing or evaluation, or process control through inspection. In a FMEA, risk is the substitute for failure. This risk is treated as if the failure had already occurred and corrective action is required. The reversal of this principle is the 8D (Eight Disciplines of Problem Solving). A FMEA is an 8D before an 8D is necessary.

How Do I Analyze a FMEA? – Criticality vs. RPN

The RPN (Risk Priority Number) is the product of Severity, Occurrence and Detection (RPN = S∗O∗D), and is often used to determine the relative risk of a FMEA line item. In the past, RPN has been used to determine when to take action. RPN should not be used this way. Q-1 recommends never using RPN for action determination.

Actions are determined by Criticality. Criticality is the combination of Severity and Occurrence as displayed in the Q-1 Criticality Matrix.

The actions, when completed, move the risk from its current position in the Q-1 Criticality Matrix to a lower risk position. Items with the greatest risk are based on Severity of the effect combined with the likelihood of its Occurrence in a specific cause. When risk is determined to be too high, Q-1 recommends the priority of action to be applied as follows:

  1. Error Proofing

    • a. Failure Mode (Only Severity of 9 or 10)
    • b. Cause with High Occurrences

  2. Improve Potential Process Capability

  3. Control Plan Methodology (Improve Controls)

    • a. Mistake Proofing of the Tooling or Process
    • b. Improve the Inspection and Evaluation Techniques

How Do I Create a FMEA?

Q-1 FMEA Development Methodology follows a Three Path Model. With the combination of pre-work documentation, evolving team structure and action closure, a FMEA becomes the road map for improvement in the design of products or processes. Severity for each Effect of Failure is defined in Path 1 by a core team; Occurrence is selected in Path 2 by an expanded team of SMEs (Subject Matter Experts); and Detection is chosen in Path 3 with testing or inspection personnel. The Q-1 development steps are as follows:

Step 1: Pre-Work

Pre-work documentation includes: the creation of a core team, the preparation or collection of Robust Engineering Tools for DFMEA, and Special Characteristics and Process Flow Diagrams (PFD) for PFMEA. DFMEA Robustness Tools used in development include:

Step 2: Three Path Model

Q-1’s Design FMEA ION approach uses the tools listed above to populate the FMEA. Here is an example of ION usage in a cause column:

  • Inside (the boundary on the Boundary Diagram)
  • Outside (the Boundary Diagram Interfaces)
  • Noise (from the Parameter Diagram’s 5 Noises)

This Q-1 approach ensures that the FMEA is performed in a structured way, avoiding confusion and inconsistency found in other brainstorming methods.

Step 3: Post-Work

A FMEA is not complete until all actions have been completed and the risk is re-ranked. Assuming the actions were generated from the Three Path Model, three actions are possible:

  • Failure Mode Elimination
  • Cause Treatments Reducing Occurrence
  • Improved Controls Strategy

If these actions were successful, the Occurrence or Detection ranking will decrease. In rare occasions, Severity can be eliminated by removing a Failure Mode through design improvement.

How Can I Learn More About FMEA?

Details of how a FMEA works and its benefits can be obtained by scheduling Facilitation or Training with Q-1.

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