Updated: Sep 11, 2020
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
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
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 :
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 purpose of this activity is to clarify the process purpose
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.
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.
Intended to reduce the ranking for
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.