Step 1: Assemble the Team
- Objective: Form a cross-functional team with members from different departments such as engineering, manufacturing, quality, and other relevant areas.
- Key Activities: Select members with diverse expertise and knowledge about the process. Define roles and responsibilities.
Step 2: Describe the Process
- Objective: Develop a clear and detailed understanding of the process.
- Key Activities: Use process flow diagrams, process maps, or standard operating procedures to describe each step in the process. Ensure all team members understand the process thoroughly.
Step 3: Identify Potential Failure Modes
- Objective: Identify all the ways in which the process could potentially fail.
- Key Activities: Brainstorm potential failure modes for each step of the process. Consider both common and rare failure scenarios.
Step 4: Determine Failure Causes
- Objective: Identify the root causes of each potential failure mode.
- Key Activities: Analyze each failure mode to determine why it might occur. Use tools like 5 Whys or fishbone diagrams for in-depth analysis.
Step 5: Assess Effects and Severity
- Objective: Understand the impact of each failure on the process and the end user.
- Key Activities: For each failure mode, identify the consequences and rate the severity of these effects on a scale (e.g., 1-10).
Step 6: Identify Current Controls
- Objective: Document existing controls that prevent failures or detect them before they impact the customer.
- Key Activities: List all current process controls, such as inspections, tests, or error-proofing methods.
Step 7: Evaluate Likelihood of Occurrence
- Objective: Assess the probability of each failure mode occurring.
- Key Activities: Assign a likelihood rating to each failure mode based on historical data, experience, or risk assessment (e.g., 1-10).
Step 8: Assess Detection
- Objective: Evaluate the ability of current controls to detect or prevent the failure mode.
- Key Activities: Rate the effectiveness of detection controls on a scale (e.g., 1-10), where a lower number indicates better detection capability.
Step 9: Calculate Risk Priority Number (RPN)
- Objective: Quantify the risk associated with each failure mode.
- Key Activities: Calculate the RPN for each failure mode by multiplying Severity, Occurrence, and Detection ratings.
Step 10: Prioritize Actions and Develop Action Plans
- Objective: Focus on the highest risks and plan actions to mitigate them.
- Key Activities: Prioritize failure modes based on RPN and other factors. Develop action plans to reduce severity, occurrence, or improve detection.
Step 11: Implement Actions
- Objective: Execute the action plans.
- Key Activities: Assign responsibilities and timelines for implementing the actions. Ensure resources are available.
Step 12: Review and Update the PFMEA
- Objective: Ensure the PFMEA remains a living document.
- Key Activities: Regularly review the PFMEA for changes in the process, and update it as necessary.
PFMEA Form Description
A typical PFMEA form is a tabular document with several columns, each corresponding to a key component of the analysis:
- Process Step: Description of each step in the process.
- Potential Failure Mode: Listing of ways in which the process could fail at each step.
- Potential Effects of Failure: Description of the consequences of each failure.
- Severity: Numeric rating of the severity of each effect.
- Potential Causes of Failure: Reasons why each failure might occur.
- Occurrence: Numeric rating of the likelihood of each failure.
- Current Process Controls: List of existing controls that prevent or detect failures.
- Detection: Numeric rating of the ability of controls to detect the failure.
- RPN: Risk Priority Number, calculated as Severity x Occurrence x Detection.
- Recommended Actions: Suggestions for reducing risk.
- Responsibility: Person or team responsible for each action.
- Action Results: Outcome of the implemented actions, including updated RPN.
Creating a PFMEA is a detailed and thorough process that requires collaboration, expertise, and ongoing commitment to process improvement. The PFMEA form acts as a living document that evolves with the process it analyzes.