Six Sigma and Beyond: Design for Six Sigma, Volume VI

The third portion of the FMEA form deals with the action plans and results analysis. A typical format is shown in Figure 6.18.

Figure 6.18: Action plans and results analysis.

The idea of this third portion of the FMEA form is to generate a strategy that reduces severity and occurrence and makes the detection effective to reduce the total RPN:

• Reducing the severity rating (or reducing the severity of the failure mode effect)

  • Design or manufacturing process changes are necessary.

  • This approach is much more proactive than reducing the detection rating.

• Reducing the occurrence rating (or reducing the frequency of the cause)

  • Design or manufacturing process changes are necessary.

  • This approach is more proactive than reducing the detection rating.

• Reducing the detection rating (or increasing the probability of detection)

  • Improving the detection controls is generally costly, reactive, and does not do much for quality improvement, but it does reduce risk.

  • Increased frequency of inspection, for example, should only be used as a last resort. It is not a proactive corrective action.

CLASSIFICATION AND CHARACTERISTICS

Different industries have different criteria for classification. However, in all cases the following characteristics must be classified according to risk impact:

• Severity 9, 10: Highest classification (critical)

  These product- or process- related characteristics:

  • May affect compliance with government or federal regulations (EPA, OSHA, FDA, FCC, FAA, etc.)

  • May affect safety of the customer

  • Require specific actions or controls during manufacturing to ensure 100% compliance

• Severity between 5 and 8 and occurrence greater than 3: Secondary classification (significant)

  These product- or process-related characteristics:

  • Are non-critical items that are important for customer satisfaction (e.g., fit, finish, durability, appearance)

  • Should be identified on drawings, specifications, or process instructions to ensure acceptable levels of capability

• High RPN: Secondary classification (see Table 6.7)

  Table 6.7: Special Characteristics for Both Design and Process

  FMEA Type	Classification	Purpose	Criteria	Control
  Design	YC	A potential critical characteristic (Initiate PFMEA)	Severity = 9 “10	Does not apply
  Design	YS	A potential significant characteristic (Initiate PFMEA)	Severity = 5 “8 Occurrence = 4 “10	Does not apply
  Design	Blank	Not a potential critical or significant characteristic	Severity < 5	Does not apply
  Process	Inverted delta	A critical characteristic	Severity = 9 “10	Required
  Process	SC	A significant characteristic	Severity = 5 “8 Occurrence = 4 “10	Required
  Process	HI	High impact	Severity = 5 “8 Occurrence = 4 “10	Emphasis
  Process	OS	Operator safety	Severity = 9 “10	Safety sign-off
  Process	Blank	Not a special characteristic	Other	Does not apply

Product Characteristics/"Root Causes"

Examples include size , form, location, orientation, or other physical properties such as color , hardness, strength, etc.

Process Parameters/" Root Causes"

Examples include pressure, temperature, current, torque, speeds, feeds, voltage, nozzle diameter, time, chemical concentrations, cleanliness of incoming part, ambient temperature, etc.

DRIVING THE ACTION PLAN

For each recommended action, the FMEA team must:

• Plan for implementation of recommendations

• Make sure that recommendations are followed, demonstrate improvement, and are completed

Implementation of action plans requires answering the classic questions...

• WHO ... (will take the lead)

• WHAT... ( specifically is to be done)

• WHERE ... (will the work get done)

• WHY... (this should be obvious)

• WHEN... (should the actions be done)

• HOW... (will we start)

Additional points concerning the action plan include the following:

• Accelerate implementation by getting buy-in (ownership).

• It is important to draw out and address objections.

• When plans address objections in a constructive way, stakeholders feel ownership in plans and actions. Ownership aids in successful implementation.

• Typical questions that begin a fruitful discussion are:

  • Why are we...?

  • Why not this...?

  • What about this...?

  • What if...?

• Timing and actions must be reviewed on a regular basis to:

  • Maintain a sense of urgency

  • Allow for ongoing facilitation

  • Ensure work is progressing

  • Drive team members to meet commitments

  • Surface new facts that may affect plans

• Fill in the actions taken.

  • The "Action Taken" column should not be filled out until the actions are totally complete.

  • Record final outcomes in the Action Plan and Action Results sections of the FMEA form. Remember, because of the actions you have taken you should expect changes in severity, occurrence, detection, RPN, and new characteristic designations. Of course, these changes may be individual or in combination. The form will look like Figure 6.19.

    Figure 6.19: Transferring action plans and action results on the FMEA form.