What is Failure Mode and Effects Analysis (FMEA)?

Failure mode and effects analysis (FMEA) is a systemised approach for eliminating failure during product development or for quality improvement activities. As such, it is an integral part of advanced quality planning, and is often a pre-requisite for automotive and aerospace manufacturers and their supply chain. It may be focused on the design (Design FMEA or DFMEA) or processes (Process FMEA or PFMEA). In most cases, the DFMEA feeds into the PFMEA and this determines the order in which the two are addressed.

Failure modes and effects analysis has also been used successfully to defend product liability claims in court, and many organisations have taken up the approach due to the protection that it can provide in this area.

As with many powerful techniques, the strength of FMEA analysis is derived from a cross-functional, team-based approach.

Also called potential failure modes and effects analysis; failure modes, effects and criticality analysis (FMECA); FMEA is often used early in a product’s concept / development stage to avert any in-service or manufacturing failures.

Effective FMEA takes a step-by-step approach to identify all possible failures in a design, product, service or manufacturing and assembly process. FMEA can be split into the ‘failure mode’ and the ‘effects analysis,’ as follows:

Failure Modes are the ways in which something might fail. These failures are either potential or actual errors or defects that may affect a customer
Effect Analysis is the study of the consequences of a failure. Failures are prioritised according to how serious the consequences are, how often the failure will occur and how easy they are to detect.

The purpose of FMEA is to take actions to eliminate or reduce failures, beginning with the highest priority, high risk ones. To achieve this, FMEA documents the current knowledge and actions regarding the risk of failure and seeks continuous improvement.

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Procedure
When should it be applied?
When was it developed?
Where is FMEA used?
Examples

FMEA at TWI

TWI has experience of assisting our Industrial Members with failure mode and effects analysis, including as part of asset integrity management and other risk-based management. This includes projects to assess fitness-for-service inspection for ships and pipeline integrity management for oil and gas.

For more information, please contact us:

contactus@twi.co.uk

FMEA Procedure

The objective of FMEA is to capture the aspects of potential product or process failure, including:

What may go wrong (The failure mode)
What the result of the failure may be (the effects of failure)
How severe the result of the failure may be (the severity of failure)

FMEA assessments often require multi-disciplinary teams with a diverse understanding of a process, including design, manufacture, quality, testing, reliability, maintenance, purchasing, sales, marketing and customer service. These experts will determine the scope of the FMEA, which can then be detailed in an FMEA table, showing potential failures and consequences.

The FMEA assigns a numerical value of between 1 and 10 to the severity of the failure (S), the occurrence of the failure (O), and the likelihood of the failure being detected (D). Within these numerical values, 1 shows a low impact and 10 is the highest impact. The values are specific to each business but will encompass existing design controls, QA systems, process controls or inspection procedures, to show how likely it is that a given failure mode will be detected or predicted.

By multiplying the values (S x O x D), a risk priority number (RPN) is created so that work can be prioritised according to the severity and likelihood of failure. This allows recommended actions to be taken. The corrective actions can be design or process related as well as improving detection.

The live failure mode effects analysis document can be updated and used for derivative products as well as providing a store of organisational design or process knowledge. This document will include the occurrence ranking, detection ranking, and process controls to prevent the failure from occurring. The failure mode may also have a critical characteristic associated with it, meaning that there is a need to comply with regulations that use special controls. Critical characteristics will usually have a severity rating of 9 or 10 and occurrence and detection ratings above 3. Severity ratings of 8 or 9 in the DFMEA are usually highlighted for action regardless of the total RPN, as they are deemed critical.

When FMEA Should be Applied

FMEA is necessary in a range of situations related to products, processes and services, whether they are new or being adapted or redesigned for a different purpose. It is also worth undertaking FMEA periodically through the life of a process, product or service to ensure it is still effective and safe.

FMEA should be used:

When a product, process or service is being designed or redesigned following a quality function development
When an existing process, product or service os being applied in a new manner
Before the development of control plans for a new or modified process
When planning improvement goals for an existing service, product or process
When assessing a failure in an existing process, product or service
To periodically assess a process, product or service

When was FMEA Developed?

FMEA was developed in the 1040s by the U.S. military as a method to eliminate the root causes of malfunctioning munitions. This led to the development of a method known as MIL-P-1629, and soon saw FMEA adopted by the nuclear and aerospace industries.

NASA credits the use of FMEA for the successful moon landings and also used a version of the procedure called HACCP (Hazard Analysis and Critical Control Points) to prevent food contamination on space missions.

Ford used FMEA in the 1970s to address a problem with the Ford Pinto that was causing fatal fires following the splitting of petrol tanks. FMEA managed to solve the problem as well as other design difficulties across the company.

In 1993, FMEA was incorporated into the automotive industry’s QS9000 standard for production. The QS9000 standard later became TS16949 and then, in 2016, IATF16949.

FMEA has also been used for semiconductors in the oil and gas industry, and for white goods and common electronic products, among other uses.

Where is FMEA Used?

As mentioned above, FMEA was originally developed by the military, but since then it has been used by a wide range of industries, from semiconductors in oil and gas to food services, healthcare, plastics and even software.

Toyota expanded on FMEA to create its own Design Review Based on Failure Mode (DRBFM) approach, which is now supported by the American Society for Quality.

However, standard FMEA as well as Failure Modes, Effects and Criticality Analysis (FMECA) struggle to model product failure mechanisms without specialised software. As a result, Failure Modes, Mechanisms and Effect Analysis (FMMEA) is often used for critical procedures like virtual qualification, root cause analysis, accelerated test programmes, and remaining life assessment.

Examples

FMEA is used across a wide range of industries from healthcare and manufacturing to software development and for a range of product and process life cycles. It is important for any industry to be able to discover failures, or potential failures, as quickly as possible so they can be mitigated against to improve safety and quality, save money and please customers.

Some example uses of FMEA include:

Agriculture

FMEA is used in agriculture for environmental, ethical and legal reasons, including assessing the environment, machinery and manufacturing processes as well as product quality.

Healthcare

Healthcare applies FMEA as a tool to identify processes that need improvement to reduce risks to both patients and staff.

Manufacturing

Manufacturing uses FMEA widely to anticipate and eliminate potential failures in procedure and products. This avoids having to take on expensive corrective actions later and creates reliable, high-quality products to satisfy customer demands.

Software Development

FMEA in software development is used to improve quality, reduce costs and lower defect density to provide effective products for end-users.

Transport and Logistics

FMEA is also used to evaluate and improve logistics and supply chains to deliver a high-quality service to customers.

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