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Saturday, March 24, 2012

The Purpose of an FMEA




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, and the ability to Detect the failure or effect.


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.


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


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


Assembling an FMEA Team


FMEAs should always be conducted by teams.


The best size for an FMEA team is 4 to 6 people, carefully selected, based on the contribution they can make to the specific FMEA.


An FMEA team should represent a cross-section of the company in terms of functional responsibility and level in the organization. Team members typically come from:

Manufacturing


Engineering


Materials/Purchasing


R & D


Maintenance


Quality


Tech Service


Customers


Suppliers


FMEA team members do not necessarily need to have extensive knowledge of the design or process being targeted. In fact, sometimes it helps to get an outsider's fresh perspective.


The FMEA team needs a leader to help set up and facilitate meetings, to ensure the team has the necessary resources, and to make sure the team is progressing toward completion of the FMEA.


Monday, March 12, 2012

What You Need to Know About Failure Mode and Effects Analysis (FMEA)


Every product or process has modes of failure. The effects represent the impact of the failures. An FMEA is a tool to:
1. Identify the relative risks designed into a product or process.


2. Initiate action to reduce those risks with the highest potential impact.


3. Track the results of the action plan in terms of risk reduction.


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, and the ability to detect (or prevent) the failure or effect.


RPN = Severity rating X Occurrence rating X Detection rating


The RPN can range from a low of 1 to a high of 1,000


Once the RPNs are determined, you need to develop an Action Plan to reduce the risks of failure modes of unacceptably high RPNs. Next, use the FMEA as the basis for developing a Control Plan. Control Plans are a summary of defect