ONE GOOD IDEA
Failure Is an Option
Integrating FMEA into the product life cycle
by Wayne Stansbury and Kristine Beenken
As a reliable means of identifying potential failures before they happen, failure mode and effects analysis (FMEA) deserves a place in every product life cycle. By incorporating an FMEA, organizations can move from sequential to parallel processing of a variety of FMEAs, a summary of which you can find in Online Figure 1.
The purpose of the concept FMEA (CFMEA) is to analyze the functions of systems, subsystems or components early in the product life cycle so you can define the best design, identify risks and allocate resources accordingly. Concept risks should be addressed and the CFMEA completed during the feasibility phase.
Usually, the CFMEA is not updated in the other product life cycle phases because the design is being worked on using design FMEA in the feasibility phase, and concept revisions after the feasibility phase would be considered scope changes.
The application FMEA (AFMEA) focuses on how the application—for example, a machine that runs constantly for a short period of time and then lies dormant—makes the machine not work as intended.
The AFMEA should be started during the concept phase to identify risks when meeting customers’ applications. It should be completed during the feasibility phase so the design team has time to address application risks as it moves toward design FMEA (DFMEA). The AFMEA can be conducted on an existing product later in its life cycle to enhance usefulness or safety.
The purpose of the DFMEA is to assist the creation of a product design that meets the customer’s requirements. The DFMEA should start in the feasibility phase to begin addressing concept or application risks identified during the CFMEA or AFMEA. The recommended actions should be identified during the develop phase to identify design risks and to obtain input from the manufacturing team.
The recommended actions for a DFMEA must be completed prior to production. Input from manufacturing early in the DFMEA process allows time for design changes that eliminate nonvalue-added process steps, reduce defects and shorten processing time.
The purpose of the process FMEA (PFMEA) is to prioritize process risk and take action to eliminate or mitigate the risk, resulting in a process that will meet the customer’s requirements. The PFMEA should be worked through the severity column while identifying recommended actions in the DFMEA. This overlap improves communication between design and manufacturing.
The CFMEA, AFMEA, DFMEA and PFMEA should be completed before the first production run. Because FMEAs are considered living documents, facets of them should be updated—including re-ranking severity, occurrence and detection—as scope, application, design and process changes occur throughout the product life cycle.
A reverse FMEA (RFMEA) and service FMEA (SFMEA) can be initiated as soon as the manufacturing team has production-intent parts in the production phase. This will help address human factors and process risks by reducing defect opportunities.
In an RFMEA, operators are asked to install components upside down or backward—or omit them completely. Then, it is noted how far down the line the assembly progresses before the defect is detected. This helps identify where improved detective controls are needed.
The SFMEA is a tool to identify potential or known service failure modes and to mitigate these failures before the first service run. The RFMEA and SFMEA should also be completed within the production phase to identify risks to the design or manufacturing process.
Keep in mind these are intended as guidelines for FMEA timing and may not apply to every product life cycle. But hopefully, these suggestions will motivate organizations to institute parallel processing of FMEAs, ultimately leading to improved product quality.
Wayne Stansbury is a lean Six Sigma manager for Heard & Smith in San Antonio. He earned a bachelor’s degree in math from Texas A&M University-Corpus Christi. Stansbury is an ASQ senior member.
Kristine Beenken is the DFMEA facilitator for John Deere Power Systems in Waterloo, IA. She earned bachelor’s degrees in applied physics from the University of Northern Iowa in Cedar Falls and in mechanical engineering from Iowa State University in Ames.