FAILURE MODE EFFECTS ANALYSIS vs FAULT TREE ANALYSIS

By:
SR Parthasarathy &T Santosh Kumar
FAILURE MODE EFFECTS ANALYSIS
vs
FAULTTREE ANALYSIS
GMP Pharma Consultants
www.gmppharmaconsultants.com

Introduction
As per ICH Q9 “Risk is defined as the combination of the
probability of occurrence of harm and the severity of that harm.

Application of Quality Risk Management [QRM]
Development &
Manufacturing
API
Distribution, inspection
and submission/review
processes of drug
substances
Finished Product
Biological and
biotechnological products
(including the use of raw
materials, solvents,
excipients
Biotech Products
Packaging and labeling
materials in drug
(medicinal) products,
Packaging Material
QRM
Applications

Some importantTechniques for Quality Risk Assessment:
Basic risk management facilitation methods (flowcharts, check sheets etc.);
• Failure Mode Effects Analysis (FMEA);
• Failure Mode, Effects and Criticality Analysis (FMECA);
• FaultTree Analysis (FTA);
• Hazard Analysis and Critical Control Points (HACCP);
• Hazard Operability Analysis (HAZOP);
• Preliminary Hazard Analysis (PHA);
• Risk ranking and filtering;
• Supporting statistical tools.

FAILURE MODE, EFFECTS AND ANALYSIS
“The Failure Mode, Effects and Criticality Analysis (FMECA) is a reliability
evaluation/design technique which examines the potential failure modes within a
system and its equipment, in order to determine the effects on equipment and
system performance. Each potential failure mode is classified according to its
impact on mission success and personnel/equipment safety.”
It is a bottom-up method, starting at the component level, which is used to find
failure modes and to identify their effects. By adding a criticality analysis,
qualitative FMEA becomes quantitative FMECA (failure mode, effects and
criticality analysis).

FAILURE MODE, EFFECTS AND ANALYSIS
In FMECA, the criticality of each failure mode is quantified by the risk priority
number (RPN).
The risk priority number is the product of three indicators: (a) severity indicator
(S), (b) occurrence indicator (O) and (c) detection indicator of a failure (D).
indicators are usually rated on a scale from 1 to 10
Therefore RPN = S x O x D
Risk is calculated based on a 1 to 1000 point scale

FAILURE MODE, EFFECTS AND ANALYSIS - Disadvantages
Holes in the scale: Many of the numbers in the range of 1 to 1000 (assuming 10-point scoring scales are used) cannot
be formed from the product of severity, probability and detectability.
88% of that range is empty with the first four possible RPN values covering 0.4% of the scale, while the last four values cover
20% of the scale.
No number having a prime factor greater than 10 can be formed.Thus the numbers 11, 22, 33 or even 990, which are all
multiples of 11 cannot be formed and are excluded.
1000 is the largest number, but 900 is the second largest followed by 810, 800, 729 and 720.
In this case, can we say that the difference between 810 and 900 is the same or less than the difference between 900 and
1000?
Duplicate RPNValues:
Severity Probability Detectability RPNValue
3 8 8 192
8 3 8 192

FAILURE MODE, EFFECTS AND ANALYSIS - Disadvantages
Sensitivity of RPNValues for minor Changes:
Small variations in one scoring scale can lead to very different effects on RPN, depending on the
values of other factors.
Severity Probability Detectability RPNValue
4 8 8 256
9 3 8 216

FaultTree Analysis
The second method for failure analysis is FaultTree Analysis (FTA), which is a
top-down method used to identify relationships between events, such as
subsystem failures and their causes.
FaultTree Analysis (FTA) is a deductive failure analysis which focuses on one
particular undesired event and provides a method for determining causes of this
event.
In other words, a FaultTree Analysis is a “top-down” system evaluation
procedure in which a qualitative model for a particular undesired event is formed
and then evaluated.”

Implementation of the method requires considerable inputs, because more
process details lead to a geometric increase in the analyzed area, and the number
of influencing events grows correspondingly.
• A fault tree is a Boolean logic diagram, which shows only two states: work and
fail.
• Partial Failure cant be estimated, because use of the method generally
indicates that the process is either in good condition or in a faulty state.
• It requires a reliability specialist with deep knowledge of the process.
FaultTree Analysis - Disadvantages

What is the Correct Approach

Option 1: perform both an FMEA as well as an FTA separately
The 1st Option may expand the number of failure modes found due to the different starting
points of both methods: bottom-up in FMEA, versus top-down in FTA.
Option 2: Using a Mixed Approach
Here, FMEA is guided by a FTA. In their proposed approach, the analysis starts with the
definition of a system failure event and continues with the construction of a fault tree for a
particular system as a whole.
Performing both analyses would be time consuming and may lead to a loss of focus on the
most critical parts of the system, which the failure analysis typically aims to identify.
Finally, each basic event is analyzed further with FMEA to identify the underlying failure modes
of each component.
Combination of FMEA & FTA

VARIATION MODE, EFFECTS AND ANALYSIS - BETTER OPTION
Today, many failures are caused by variations (strength, loads, manufacturing tolerances, etc.),
resulting in expensive reclamations and dissatisfaction that may lead to loss.
Variation Mode and EffectAnalysis (VMEA), a relatively new methodology, which is a deductive
method of identifying and managing sources of variation.
TheVMEA method has been decomposed into three different levels:
BasicVMEA BasicVMEA is used in the early design stages, where information about
the variation is vague and the aim is to compare and evaluate different
concepts.
EnhancedVMEA EnhancedVMEA is used later in the design stages, where more
information about the sources of variation is known.
ProbabilisticVMEA. ProbabilisticVMEA is used in late design stages, where detailed and
statistical information about sources of variation is available.

Worked with over
300 Clients spread
across 35 countries
Special Due Diligence in
DPR Preparation,
Project Planning &
Management, Audits,
Risk Assessment & CAPA
Established Regulatory
Compliance in
accordance with US
FDA, WHO,TGA, GCC &
DCGI/CDSCO
Value Creation across all segments of
Pharmaceuticals ranging from API, Intermediates,
Formulations, Medical Devices, Ayurvedic
Medicines & Processed Foods
About Us
GMP PharmaConsultants are in a position to provide a one stop solution to pharmaceutical & Food enterprises for
all their needs

Some of our esteemed Clients include:

Contact:
Visit: www.gmppharmaconsultants.com
Habsiguda, Hyderabad, India.
E-mail: srpsarathy@gmail.com
MVP Colony,Visakhapatnam, India.
E-mail: santoshkumar.tata@gmail.com
Thank you

FAILURE MODE EFFECTS ANALYSIS vs FAULT TREE ANALYSIS

Recommended

Recommended

More Related Content

What's hot

What's hot (20)

Similar to FAILURE MODE EFFECTS ANALYSIS vs FAULT TREE ANALYSIS

Similar to FAILURE MODE EFFECTS ANALYSIS vs FAULT TREE ANALYSIS (20)

Recently uploaded

Recently uploaded (20)

FAILURE MODE EFFECTS ANALYSIS vs FAULT TREE ANALYSIS