FMEA (FAILURE MODE AND EFFECTS ANALYSIS)

Updated: Sep 11

What is FMEA?


A Systematic analysis of the process used to identify potential failure and to prevent their occurrence


FMEA is meant to be a " before the event" action, not an "after the fact" exercise


Types of FMEA


1-System:- Top-level, early-stage analysis of the complex system.

2-Design:- Systems, subsystems, parts & components early in the design stage.

3-Process- Focused on process flow, sequence, equipment. tooling, gauges, inputs, outputs, setpoints, etc.


Benefits of FMEA


Improvement in

  • Safety

  • Quality

  • Reliability

  • by anticipating Potential Failure and improving upon current preventive and defective control

FMEA Characteristic :

  • The FMEA is a living document

  • Should always reflect

the latest level as well as

the relevant action

including those occurring after the start of production and control plants

Basic structure

As AIAG manual there are 8 PFMEA formats, use of Specific format may vary based on the need of organization and the requirement of the customer


fundamentally the format utilized should address :


1- Functions

2-Requirements and deliverable

3-failure modes when functional requirement are not met

4-Effects and consequences of the failure mode

5-Potential causes of the failure mode

6-Actions and controls to address the causes of the failure mode and

7-Action to prevent recurrence of the failure mode

FMEA Required to Identify and understand

  • The Functions

  • Requirements

  • Specifications

The purpose of this activity is to clarify the process purpose

FMEA AIAG Format -Click here


FMEA Number (A):- Enter an alphanumeric string which is used to identify the FMEA documents. this is used to control the documents.

Item (B):- Enter the name of the component for which the process is being analyzed.

Responsibility (C):- Enter the organization, department or group who is process design responsible.

Model (D):- Enter the intended model that will use by the process being analyzed

Key Date (E):- Enter the initial PFMEA due date which should not exceed the scheduled start of production date.

FMEA Date (Orig) (F):- Enter the date of the original FMEA was completed.

Core team (G):- Enter the team members responsible for developing the FMEA.

Prepared By (H)- Enter the name of the engineer/team leader responsible for preparing the FMEA.


Definitions :


1- Failure mode:-means the ways, or modes, in which something might fail. Failures are any errors or defects, especially ones that affect the customer and can be potential or actual.

Example:- missing part, oversized, Undersized, etc.

2-Failure Mechanism:- it is a manner in which a product or a process can progressively fail to meet specification or which can lead failure in other parts of a system and or subsequent process stage.

Example:- corrosion, inaccuracy of measuring devices, etc.

3-Cause:- Causes are the source of variation which are associated with key process inputs (6Ms).

Example:- instruction not followed, lack of experience, incorrect documents, etc.

4-Effect:-Effect is the impact of the customer (both internal and external) if the failure mode is not prevented or corrected.

Example-Customer dissatisfaction, Frequent product breakdown, etc.



Process FMEA Terminology

1-Severity:- an assessment of the seriousness of a failure mode severity applies to the effects only.

2-Occurance:- The likelihood that Specific failure mode is projected to occur.

3-Detection:- The effectiveness of the current process control to identify the failure mode prior to occurring


PFMEA Severity table

PFMEA Occurance Table

PFMEA Detection table

Risk Priority Number (RPN)


RPN=S X O X D

There are no "threshold" values, special attention should be given when severity is high.


Recommended Action


Intended to reduce the ranking for

  • Severity

  • Occurrence

  • Detection

Note-1 Severity can be reduced only if the design of the product/process changes.

Note-2 The occurrence can be reduced by Improving preventive controls.

Note-3 Detection Ranking can be reduced by improving the detection controls.