Failure mode and effects analysis (FMEA)

Failure mode and effects analysis (FMEA) is a step-by-step methodology used to identify potential failures in a design or process. People use FMEA most often in industry to reduce errors in manufacturing, but it can apply to many other fields as well, such as science, agriculture, software development, healthcare, and the military. The term failure mode refers to a way in which a design or process may experience an error or defect that affects the customer. The methodology was invented in the mid-1900s for military purposes but became a standard in many fields, military and civilian, during the following decades. FMEA is also sometimes called potential failure modes and effects analysis or failure modes, effects, and criticality analysis.

Background

In the twentieth century, science, technology, and industry progressed at a rapid pace. New inventions required intricate designs and many complex manufacturing steps. At the same time, these inventions became increasingly abundant, powerful, and demanded by consumers. Any failures in these creations or the processes by which they were made could be disastrous.

For those reasons, industries and other large organizations began focusing on the quality of their designs and processes. One of the first and most vital steps in assuring quality was reducing the risk of failures, whether in the manufacturing or in the functioning of the final product. This trend would ultimately lead to the failure mode and effects analysis (FMEA) technique.

The first attempts to create a methodology for eliminating failures began in the 1940s among US military specialists. They were trying to best manage the outpouring of increasingly powerful munitions being prepared for World War II (1939–1945), and later the even stronger weapons—including nuclear weapons—of the Cold War era.

However, FMEA first took its current state in the 1960s, as it was reworked by National Aeronautics and Space Administration (NASA) engineers to help plan and execute the Apollo missions, the first manned flights to the moon. The spacecraft needed for this endeavor were unprecedented in their complexity, and any failures in their manufacture, maintenance, or operation could cost the lives of the astronauts on board and the reputation of the country's space program.

In the 1970s, FMEA became more popular. First, the FMEA process entered use by the US Navy, which established FMEA as an official troubleshooting technique in the 1974 document MIL-STD-1629. FMEA went on to even more extensive use, however, by the end of that decade. The automotive industry, burdened by increasing consumer demands and the rising costs of liability for faulty products, adopted FMEA as an official policy for making automobiles and their manufacture safer.

Overview

By the twenty-first century, FMEA remains a common fixture in many industries and other fields. People may use FMEA for a wide variety of reasons. FMEA is most useful during the design or redesign of a product or process, as part of a quality-control program. People may also use FMEA when an existing product or process is being repurposed or has been selected for improvement. FMEA is also important after a product or process fails or shows some other weakness. In those cases, using the technique can help identify and remove the problem in the future.

Although FMEA can take different forms in different applications, in general, it is an analytical process that attempts to identify and eliminate foreseeable failures. Users prioritize failures based on several criteria, mainly how severe their consequences might be and how likely they are to occur. The potential failures of the highest priority, ones that are likely to occur and cause serious problems, are generally addressed first. People may use FMEA throughout the life cycle of a product or process, from its planning and creation through its use and results.

If performed properly, FMEA can be one of the most important and effective tools in quality control and reliability analysis. Effective FMEA involves experts and other related people brainstorming, sharing knowledge, mapping plans, and using their relevant experience to create a sound plan to find and remove failures. In addition, the FMEA process usually creates documentation of the procedures and findings, which can prove helpful to others, both in and out of the industry or organization, who can spread safe practices universally.

Many FMEA users document their work using specialized forms. These forms include charts with rows and columns for recording information such as the steps of the process, the particular failure being studied, and the likely causes and effects of that failure. As the FMEA procedure progresses, users can fill in more information, including recommended actions and what, if any, actions were ultimately taken to improve the situation.

FMEA users follow certain procedures, although the process itself may vary significantly between applications. In general, the first step is to gather a team, ideally people well versed in the topic being analyzed. Good candidates may include engineers, suppliers, marketers, operators, and even customers to whom the product or design will be offered. The team members must be made aware of the task at hand and the scope and details of their work.

Next, the team members confer in the gathering of possible failure scenarios. Each scenario is a failure mode to be recorded and analyzed. This analysis includes determining the likely consequences of each failure type and their level of severity, usually ranked on a numeric scale from 1 (no or minimal failure) to 10 (disastrous failure). Next, the analysts determine the potential root causes of the failure, and the likelihood of that failure occurring (again rated on a 1 to 10 scale).

FMEA analysts use a mathematical formula based on the level of severity, the likelihood of occurrence, and the unlikelihood of early detection to determine the RPN (risk priority number), or the order in which the failures will be examined. The analysts determine current controls over the failures and assess whether these controls are sufficient. If they are not, the FMEA analysts confer to recommend actions that can help to remove the failures.

The most common variations of FMEA include Design FMEA (DFMEA) and Process FMEA (PFMEA). DFMEA is particularly useful for early-stage planning or near the end of product design projects in identifying potential health and safety concerns of a new product. PFMEA is used before implementing new processes or changing old process guidelines to identify possible issues with quality, timing, customer satisfaction, and employee satisfaction. In addition to variations of the analysis model, other tools have been developed to improve the effectiveness of FMEA. For example, the failure mode and effect analysis and supply chain resilience (FMEA-SCR) was designed as a hybrid model for industries experiencing crisis. By quantitatively measuring the disruption and documenting the cause, organizations can be better prepared for such events in the future.

Bibliography

Carlson, Carl S. Effective FMEAs: Achieving Safe, Reliable, and Economical Products and Processes Using Failure Mode and Effects Analysis. John Wiley & Sons, 2012.

"FMEA: Definition, Steps, Types, & Tools." SafetyCulture, 23 Jan. 2024, safetyculture.com/topics/fmea. Accessed 1 Dec. 2024.

"FMEA (Failure Modes and Effects Analysis)." University of Cambridge, www.ifm.eng.cam.ac.uk/research/dmg/tools-and-techniques/fmea-failure-modes-and-effects-analysis. Accessed 1 Dec. 2024.

Forrest, George. "FMEA (Failure Mode and Effects Analysis) Quick Guide." iSixSigma, 23 Sept. 2024, www.isixsigma.com/fmea/fmea-quick-guide. Accessed 1 Dec. 2024.

Palady, Paul. Failure Modes and Effects Analysis. PT Publications, 1995.

"Recommended Failure Modes and Effects Analysis (FMEA) Practices for Non-Automobile Applications." SAE International, 7 Aug. 2020, www.sae.org/standards/content/arp5580. Accessed 1 Dec. 2024.

Stamatis, D. H. Failure Mode and Effect Analysis: FMEA from Theory to Execution. ASQ Quality P, 2003.

Tague, Nancy R. The Quality Toolbox. 3rd ed., ASQ Quality P, 2023.

"What Is FMEA? Failure Mode & Effects Analysis." American Society for Quality, asq.org/quality-resources/fmea. Accessed 1 Dec. 2024.