What is FMEA and FMECA?

This blog is part of a series of blogs published by UReason about failure modes and effect analysis of essential components that are common in various industrial processes such as control valves, pneumatic actuators, electrical actuators, motors, and centrifugal pumps.

Introduction to FMEA & FMECA

FMEA and FMECA are both systematic methodologies used in various manufacturing industries to assess and improve the reliability, safety, and performance of products, processes, or systems. However, they have some key differences:

1. FMEA:

FMEA stands for “Failure Modes and Effects Analysis.” It is a structured, qualitative analysis technique that focuses on identifying potential failure modes in a system, product, or process and assessing their consequences. The primary goal of FMEA is to prioritize these failure modes based on their severity, occurrence probability, and detectability to determine where preventive or corrective actions are needed.

Key aspects of FMEA:

• Focuses on identifying failure modes and their effects;
• Prioritizes failure modes based on severity, occurrence, and detectability (often using a Risk Priority Number, RPN); and
• Typically used in the early design or development stages to prevent problems from occurring.

2. FMECA:

FMECA stands for “Failure Modes, Effects, and Criticality Analysis.” It is an extension of FMEA that incorporates quantitative analysis to assess the criticality of failure modes more precisely. FMECA evaluates the impact of failure modes not only in terms of their severity but also in terms of their potential consequences on system safety, performance, and reliability.

Key aspects of FMECA:

• Expands on FMEA by adding a quantitative analysis component;
• Evaluates the criticality of failure modes by considering factors such as severity, occurrence, and the likelihood of detection; and
• Typically used in safety-critical industries such as aerospace and nuclear power, where precise risk assessment is crucial.

In summary, FMEA and FMECA are both valuable tools for risk assessment and management. FMEA is a qualitative technique that identifies and prioritizes failure modes based on their potential effects, while FMECA extends FMEA by incorporating quantitative analysis to assess the criticality of these failure modes more accurately.

Establishing A Process for FMEA & FMECA

The choice between FMEA and FMECA depends on the specific needs and requirements of your industry and the level of precision needed in the analysis. FMECA is typically used in safety-critical applications where a more rigorous risk assessment is essential.

Setting up a Failure Modes and Effects Analysis (FMEA) involves a systematic process that helps identify and prioritize potential failure modes and their effects. The general steps to set up an FMEA are:

1. Define the Scope and Objectives:

Clearly define what you want to analyse with the FMEA. This could be an asset, a process, a system. Also set the boundaries of what will and will not be included in the analysis.

Set clear objectives for the analysis, such as improving safety, reliability, or performance.

2. Assemble a Cross-Functional Team:

Form a team of experts or individuals from various relevant disciplines, including process, electrical and instrumentation, operations, maintenance, SHEQ and other relevant areas for your business.

Ensure that the team members have the necessary knowledge and expertise related to the subject of analysis.

3. Break Down the System:

Divide the system or process into its components or subsystems – use as guidance the functions the asset/process needs to provide. This breakdown helps in a more focused analysis.

4. Identify Failure Modes:

For each component or subsystem, brainstorm and list all possible failure modes. Failure modes are the different ways in which a component or subsystem can fail or malfunction.

5. Determine Effects and Consequences:

For each identified failure mode, assess the potential effects or consequences it may have on the overall system, product, or process. Consider factors like safety, performance, reliability and efficiency.

6. Assign Severity Ratings:

Assign a severity rating to each failure mode based on the potential impact of its consequences. Use a predefined scale (e.g., 1 to 10) to rank severity, with higher numbers indicating more severe consequences.

7. Assess Occurrence Probability:

Determine the likelihood or probability of each failure mode occurring. Use historical data, expert judgment, or statistical analysis to estimate the occurrence probability.

8. Assign Detection Ratings:

Evaluate the likelihood of detecting each failure mode before it reaches the end user. Assign a detection rating using a predefined scale, with higher numbers indicating a lower likelihood of detection.

9. Calculate Risk Priority Numbers (RPNs):

Calculate the Risk Priority Number (RPN) for each failure mode by multiplying the severity, occurrence, and detection ratings. RPN = Severity × Occurrence × Detection.

(This step helps prioritize which failure modes require immediate attention based on their RPN values.)

10. Prioritize and Take Action:

Prioritize the failure modes based on their RPN values. High-RPN failure modes should be addressed first.

Develop action plans to mitigate or eliminate the identified high-risk failure modes. These actions may include design changes, process improvements, or additional testing.

11. Implement and Monitor:

Implement the recommended actions and track their effectiveness in reducing the risks associated with identified failure modes.

Periodically review and update the FMEA as new data becomes available or as the system or process changes.

If you want to learn more about UReason and its knowledge resource, visit us here: https://www.ureason.com/resources/