Failure Mode and Effects Analysis Resource Center

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

All products or processes have failure modes. The effects are the impacts when the failures occur. A FMEA is a tool to:

	Identify the relative risks designed into a product or process
	Develop and take action to reduce the risks with the highest potential impact
	Track the results of the action to determine risk reduction or elimination

Failure Mode and Effects Analysis helps you focus on and understand the impact of potential failures of process or product. A ranking methodology is used to prioritize 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 before it escapes to the customer.

RPN = Severity rating X Occurrence rating X Detection rating (S x O x D = RPN)
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 Corrective/Preventive Action Plan to reduce the risks of failure modes of high RPNs.

Next, use the completed FMEA as the basis for developing a Control Plan and work instructions. Control Plans are a summary of defect prevention and reactive detection techniques and must mirror the FMEA.

FMEA Resources

	The Purpose of an FMEA
	DFMEA or PFMEA?
	The FMEA Process
	Forming an FMEA Team
	Design FMEA Scope
	10 Steps to Conduct a DFMEA
	Linking DFMEAs and Control Plans
	Getting More Out of DFMEAs
	Process FMEA Scope
	10 Steps to Conduct a PFMEA
	Linking PFMEAs and Control Plans
	Getting More Out of PFMEAs
	FMEA Limitations and Pitfalls

FMEA Forms

	FMEA Start-Up Worksheet
	Design FMEA Scope Worksheet
	Process FMEA Scope Worksheet
	Generic Severity Ranking Guidelines
	Generic Occurrence Ranking Guidelines
	Generic Detection Ranking Guidelines
	FMEA Analysis Worksheet - Part 1
	FMEA Analysis Worksheet - Part 2

Helpful Hints to Make FMEAs More Effective

Customize the ranking guidelines.

While industry guidelines suggest customizing generic ranking guidelines, it is not a requirement. However, by taking the time to add organization-specific examples of applications of the ranking definitions, FMEA teams will have an easier time applying the rankings. The use of meaningful, relevant examples saves teams time and improves consistency of rankings from team to team. Use the same ranking scales for all similar products and processes. If an organization has a wide diversity of products, for example ice cream and farm implements, different custom rankings can be developed that suit the product and the market.

Once a custom set of ranking guidelines are developed, use them for every FMEA study conducted for the product line and related processes. By using the same ranking guidelines, the RPN for every failure mode and resulting effect can be compared on a relative level and the highest potential risks for the organization can identified.

Add a Process Control Plan right to the FMEA Worksheet

Control Plans ensure a system is in place to control the risks of the same failure modes identified in the FMEA. While Control Plans can be developed independently of FMEAs, it is time- and cost-effective to link Control Plans directly to FMEAs. The Control Plan describes how each potential failure mode will be controlled and how it should be reacted to if the failure mode does occur. To add a control plan component to an FMEA, add “columns” to the FMEA Worksheet for the control factors, the specifications and tolerances, the measurement system, sample size, sample frequency, the control method, and the reaction plan.

A critical factor for the success of the FMEA process is that the control plan is identical to the FMEA. There are software programs that basically create control plans and then work instructions based on the FMEA. These programs are great at making certain that their is no gaps between the various levels of documentation, plus being great time-savers.

Use the team approach

A team will be able to generate a more comprehensive list of potential failures than any one individual could do. A team approach will lead to a deeper and more accurate analysis of the risks associated with a process or design. The team should consist of a representative from each department that will be directly involved with the process or design.

Additional FMEA Resources

These books have consistently been in the top sellers on Amazon for technical books. They give you a simple and straightforward approach to FMEA. The last one is wriiten especially for the automotive, aerospace and manufacturing industries.

The Basics of FMEA, 2nd Edition

The FMEA Pocket Handbook

Failure Mode and Effect Analysis

Guidelines for Failure Mode and Effe...

Links To FMEA Information

FindArticles - A good resource for articles about FMEAs for various industries.

FMEA Articles at ISixSigma - Several articles on FMEA for different businesses.

FMEA Info Centre - According to the website "Everything you want to know about FMEA".