Failure Mode Effects Analysis (FMEA)
(see IEC 60812, ICH Q9) Annex I: Methods & Tools Evaluation,Annex I.2
Evaluation of potential failure modes for processes.
The likely effect on outcomes and/or product performance Once failure modes are established,risk reduction can be used to
eliminate, reduce or control the potential failures
FMEA relies on process understanding
Summarize the important modes of failure, factors causing these failures and the likely effects of these failures .
How to perform?
Break down large complex processes into manageable steps.
Failure Mode Effects Analysis (FMEA) :
Potential Areas of Use(s)
Prioritize risks
Monitor the effectiveness of risk control activities
Equipment and facilities
Analyze a manufacturing process to identify high-risk steps or critical parameters
How to perform?
- Establish a team
- Identify the known and potential failure modes:
Develop lists of known problems and brainstorm other potentials…
e.g. Product not meeting specification
Process not meeting yield requirements
Malfunctioning equipment Software problems Newly identified failure modes should be added at any time - Characterise the severity, probability and detectability -An equal number of levels is sometimes helpful,Some preference to 3, 4, 5, 6 or 10 levels,But: an even number of levels avoids the mid point,Use different scales,Linear: 1, 2, 3, 4,Exponential: 1, 2, 4, 8,Logarithmic: 1, 10, 100, 1000,Self made: 1, 3, 7, 10,Multiplying different scales will differentiate the outcome.
Severity (Consequences of failure)
10 Critical :
Predicted to cause severe impact to quality (Product out of specifications, no Expert Statement possible).
7 High :
Predicted to cause significant impact on quality (Failure to meet specifications, no Stability data, Expert Statement possible)
3 Moderate :
Predicted to cause minor impact on quality (Failure to meet specifications, Stability data available)
1 Low:
Predicted to have no/minor impact on quality of the product (Quality within specifications).
Probability (Likelihood failure will happen)
8 Regular failures :
Expected to happen regularly
4 Repeated failures :
Expected to happen in a low frequency
2 Occasional failures :
Expected to happen infrequently
1 Unlikely failures :
Unlikely to happen
Detectability (Ability to find the failure) –
4 Normally not detected:
Failure very likely to be overlooked, hence not detected (no technical solution, no manual control)
3 Likely not detected:
Failure may be overseen (manual control, spot checks)
2 Regularly detected :
Failure will normally be detected (manual control, routine work with statistical control)
1 Always detected :
Failure can and will be detected in all cases
(monitoring, technical solution available).
QRM for facilities, equipment and utilities
Failure Mode Effects Analysis (FMEA)
Experiences
Ease of applicability:
-Prospective tool
-Good tool for operators to use
-Can be used to identify critical steps for validation
-More objective than Fault Tree Analysis
-Covers minor risks
Limitations –
-Can be time and resource consuming
-Mitigation plans must be followed up
-Not a good tool for analysis of complex systems
-Compound failure effects cannot be analyzed
Incorporating all possible factors requires a thorough knowledge of characteristics and performance of the different components
of the system
-Successful completion requires
expertise, experience and good team skills
Dealing with data redundancies can be difficult.
Failure Mode,Effects and Criticality Analysis
(FMECA):
Annex I: Methods & Tools
I.3: Failure Mode, Effects and Criticality Analysis (FMECA)
(IEC 60812)
-Extended to incorporate an investigation
of the degree of severity of the consequences,
their respective probabilities of occurrence and
their detectability.
-The product or process specifications should be established
-Identify places where additional preventive actions may be necessary to minimize risks
Potential Areas of Use(s)
-Utilized on failures and risks associated with manufacturing processes.