Archive for FMEA

Detection Evaluation Criteria

FMEAs help us focus on and understand the impact of potential process or product risks.

  • A systematic methodology is used to rate the risks relative to each other.
  • An RPN, or Risk Priority Number, is calculated for each failure mode and its resulting effect(s).

The RPN is a function of three factors:

  • The Severity of the effect
  • The frequency of Occurrence of the cause of the failure
  • The ability to Detect the failure or effect

Calculating the RPN

  • The RPN = The Severity ranking X the Occurrence ranking X the Detection ranking.
  • The RPN can range from a low of 1 to a high of 1,000.

Taking action

  • Develop an Action Plan to reduce risks with unacceptably high RPNs.

Linking FMEAs to Control Plans

  • Use FMEAs as the basis for Control Plans.
  • Control Plans are a summary of proactive defect prevention and reactive detection techniques.

Occurrence Evaluation Criteria

FMEAs help us focus on and understand the impact of potential process or product risks.

  • A systematic methodology is used to rate the risks relative to each other.
  • An RPN, or Risk Priority Number, is calculated for each failure mode and its resulting effect(s).

The RPN is a function of three factors:

  • The Severity of the effect
  • The frequency of Occurrence of the cause of the failure
  • The ability to Detect the failure or effect

Calculating the RPN

  • The RPN = The Severity ranking X the Occurrence ranking X the Detection ranking.
  • The RPN can range from a low of 1 to a high of 1,000.

Taking action

  • Develop an Action Plan to reduce risks with unacceptably high RPNs.

Linking FMEAs to Control Plans

  • Use FMEAs as the basis for Control Plans.
  • Control Plans are a summary of proactive defect prevention and reactive detection techniques.

Severity Evaluation Criteria

FMEAs help us focus on and understand the impact of potential process or product risks.

  • A systematic methodology is used to rate the risks relative to each other.
  • An RPN, or Risk Priority Number, is calculated for each failure mode and its resulting effect(s).

The RPN is a function of three factors:

  • The Severity of the effect
  • The frequency of Occurrence of the cause of the failure
  • The ability to Detect the failure or effect

Calculating the RPN

  • The RPN = The Severity ranking X the Occurrence ranking X the Detection ranking.
  • The RPN can range from a low of 1 to a high of 1,000.

Taking action

  • Develop an Action Plan to reduce risks with unacceptably high RPNs.

Linking FMEAs to Control Plans

  • Use FMEAs as the basis for Control Plans.
  • Control Plans are a summary of proactive defect prevention and reactive detection techniques.

Prioritizing Risk and Taking Action to Reduce Risk

FMEAs help us focus on and understand the impact of potential process or product risks.

  • A systematic methodology is used to rate the risks relative to each other.
  • An RPN, or Risk Priority Number, is calculated for each failure mode and its resulting effect(s).

The RPN is a function of three factors:

  • The Severity of the effect
  • The frequency of Occurrence of the cause of the failure
  • The ability to Detect the failure or effect

Calculating the RPN

  • The RPN = The Severity ranking X the Occurrence ranking X the Detection ranking.
  • The RPN can range from a low of 1 to a high of 1,000.

Taking action

  • Develop an Action Plan to reduce risks with unacceptably high RPNs.

Linking FMEAs to Control Plans

  • Use FMEAs as the basis for Control Plans.
  • Control Plans are a summary of proactive defect prevention and reactive detection techniques.

AIAG-VDA FMEA-MSRs

FMEAs help us focus on and understand the impact of potential process or product risks.

  • A systematic methodology is used to rate the risks relative to each other.
  • An RPN, or Risk Priority Number, is calculated for each failure mode and its resulting effect(s).

The RPN is a function of three factors:

  • The Severity of the effect
  • The frequency of Occurrence of the cause of the failure
  • The ability to Detect the failure or effect

Calculating the RPN

  • The RPN = The Severity ranking X the Occurrence ranking X the Detection ranking.
  • The RPN can range from a low of 1 to a high of 1,000.

Taking action

  • Develop an Action Plan to reduce risks with unacceptably high RPNs.

Linking FMEAs to Control Plans

  • Use FMEAs as the basis for Control Plans.
  • Control Plans are a summary of proactive defect prevention and reactive detection techniques.

AIAG-VDA Seven-Step PFMEAs

FMEAs help us focus on and understand the impact of potential process or product risks.

  • A systematic methodology is used to rate the risks relative to each other.
  • An RPN, or Risk Priority Number, is calculated for each failure mode and its resulting effect(s).

The RPN is a function of three factors:

  • The Severity of the effect
  • The frequency of Occurrence of the cause of the failure
  • The ability to Detect the failure or effect

Calculating the RPN

  • The RPN = The Severity ranking X the Occurrence ranking X the Detection ranking.
  • The RPN can range from a low of 1 to a high of 1,000.

Taking action

  • Develop an Action Plan to reduce risks with unacceptably high RPNs.

Linking FMEAs to Control Plans

  • Use FMEAs as the basis for Control Plans.
  • Control Plans are a summary of proactive defect prevention and reactive detection techniques.

AIAG-VDA Seven-Step DFMEAs

FMEAs help us focus on and understand the impact of potential process or product risks.

  • A systematic methodology is used to rate the risks relative to each other.
  • An RPN, or Risk Priority Number, is calculated for each failure mode and its resulting effect(s).

The RPN is a function of three factors:

  • The Severity of the effect
  • The frequency of Occurrence of the cause of the failure
  • The ability to Detect the failure or effect

Calculating the RPN

  • The RPN = The Severity ranking X the Occurrence ranking X the Detection ranking.
  • The RPN can range from a low of 1 to a high of 1,000.

Taking action

  • Develop an Action Plan to reduce risks with unacceptably high RPNs.

Linking FMEAs to Control Plans

  • Use FMEAs as the basis for Control Plans.
  • Control Plans are a summary of proactive defect prevention and reactive detection techniques.

AIAG-VDA FMEAs

FMEAs help us focus on and understand the impact of potential process or product risks.

  • A systematic methodology is used to rate the risks relative to each other.
  • An RPN, or Risk Priority Number, is calculated for each failure mode and its resulting effect(s).

The RPN is a function of three factors:

  • The Severity of the effect
  • The frequency of Occurrence of the cause of the failure
  • The ability to Detect the failure or effect

Calculating the RPN

  • The RPN = The Severity ranking X the Occurrence ranking X the Detection ranking.
  • The RPN can range from a low of 1 to a high of 1,000.

Taking action

  • Develop an Action Plan to reduce risks with unacceptably high RPNs.

Linking FMEAs to Control Plans

  • Use FMEAs as the basis for Control Plans.
  • Control Plans are a summary of proactive defect prevention and reactive detection techniques.

Traditional (RPN) FMEAs

We use the phrase “Traditional (RPN) FMEAs” to refer to the way FMEAs have been conducted for over 70 years. A key distinction of these types of FMEAs is that the failure analysis process results in a Risk Priority Number or RPN that is used to prioritize failure modes for improvement and risk reduction efforts.

In 2019, the automotive industry revamped the FMEA process used in their global supply chain. We call these FMEAs AIAG-VDA FMEAs (AIAG and VDA are the American and German Automotive Industry Associations that spearheaded the task force that developed the new approach to FMEAs). A key change with the updated methodology is the elimination of the RPN. In its place are Action Priority Tables. Initially, this type of FMEA is only used in the automotive industry although we expect other industries will adopt the new process.

This section of the FMEA Resource Center, deals with the Traditional (RPN) FMEAs. If interested in the AIAG-VDA FMEA process,

History of FMEAs

History of FMEAs

FMEAs have been used as a risk identification and reduction tool for decades. The approach was developed by the United States Military in the late 1940s and was used for almost 70 years with relatively small evolutionary enhancements. In 2019, substantial changes were introduced as AIAG and VDA “harmonized” their differences for conducting FMEAs.

Background on FMEAs

The first widely known use of FMEAs was by the US Military at the end of the 1940s. The military developed the technique to reduce sources of variation and corresponding potential failures in the production of munitions – and it proved a highly effective tool.

Once it was recognized that project risk was reduced by the military’s use of FMEAs, NASA adopted the methodology as a crucial project planning technique as well. FMEAs proved to be vital to the success of the Apollo (and subsequent) NASA missions. FMEAs are widely used by the civil aviation industry to assess aircraft safety.

The automotive industry was an early adoptee of FMEAs as well. The Ford Motor Company led the way as an internal response to their safety and public relations issues with the Ford Pinto model in the mid-1970s. Other automotive manufacturers in the US, Europe and UK soon followed Ford’s lead.

AIAG was formed in 1982 to get fierce (US) auto industry competitors to collaborate and agree on standardized use of quality improvement tools and practices such as FMEAs, SPC (statistical process control), MSA (measurement system analysis) and related practices.

2019: FMEAs Get a Makeover

The AIAG-VDA FMEA Harmonization Project was a collaboration between OEMs and Tier 1 supplier members of AIAG and VDA.  It represents the culmination of a three-year project revising and improving FMEA methodology.  The result is one common foundation for FMEAs across the global automotive sectors represented by AIAG and VDA.