FMEA is a methodology that documents how an asset can fail and the consequences of each failure. It is used to identify critical assets, failure modes, and their effects. The document outlines the FMEA process which includes identifying failure modes and calculating a Risk Priority Number for each. Preventative maintenance tasks are then matched to failure modes to reduce risk. An example FMEA is provided for a pressure switch that lists potential failure modes, likelihood, severity, criticality ranking, and matched preventative maintenance tasks.

1. What is FMEA ?
F AILURE
M ODE
E FFECT
A NALYSIS

2. Failure Modes and Effects
Analysis
 is a methodology that
documents the manners in
which an asset can fail, as
well as the consequences
of each failure with regard
to production and safety.

3. Use of FMEA
• is to Identify the Asset Criticality
Ranking

4. What is Asset Criticality
Ranking?
Numeric rank of an asset with
respect to its importance to safety
and production; based on the
likelihood of a failure mode to occur,
as well as on the effects of the failure
and costs to repair

5. SCOPE OF ASSET
CRITICALITY RANKING
 is to provide the means
necessary to determine the
criticality of rotating equipment
and other assets with respect to the
asset’s importance to safety, the
environment and production

6. FMEA Methodology
1 All the possible failure modes for an
equipment is identified
2 Risk Priority Number is calculated for each
failure mode and equipment as a whole
3 All possible PM tasks for each failure mode
is identified with man-hour requirement
4 Failure Mode – PM Task matrix is
developed
5 PM tasks are selected to cover more than 70
% of risk assessed with optimum man-hour
requirement

7. FMEA - RPN
Calculation of Risk Priority
Number for the purpose of
criticality assessment.
Factors
 Likelihood of Failure
 Severity of the failure effects
 Cost to repair

8. FEMA RANKING CHART
A B C D E F G H I J K L
1
2 X Z T
3
4
N
SUM (A TO L) = Y
CRITICALITY RANKING
Sl.No. Failure mode LOF
Effect
CTR Ranking
T = X * Y * Z
CRITICALITY RANKING (N) = sum of T’s

9. Functional Failure
• Failure that results in the loss of an
asset’s ability to perform its intended
function at its desired level of
performance. A functional failure may
be a failure that results in a complete, or
partial, loss of asset performance.

10. Failure Mode
 Manner in which a functional
failure is realized; may or may
not be the root cause of the
functional failure. A functional
failure can possess one or more
failure modes.
 Failure modes should be based
on those that are plausible, or
most likely to occur, based on
the past history of the
component.

11. CONTROL VALVE
S.No Functional Failure Failure Mode
INST AIR LEAKAGE
INST AIR FAILURE
PRESSURE REGULATOR FAILURE
I/P CONVERTOR FAILURE
DIAPHRAGM FAILURE
CONTROL SYSTEM FAILURE
POSITIONER FAILURE
SOLENOID VALVE FAILURE
CONTROLLER PROBLEM
TUNNING PROBLEM
PROCESS PROBLEM
AIR REGULATOR FAULT
C/V ACCESSORIES FAULT
VALVE PASSING
ERROSION (PLUG / SEAT RING)
MECHANICAL FAULT
BLOCKAGE
MECHANICAL FAULT
DROPPING OF PLUG.
GONE TO FAIL SAFE CONDITION
VALVE HUNTING
MORE THAN REQUIRED FLOW
LESS FLOW
1
2
3
4

12. Likelihood of Failure
LIKELIHOOD CRITERIA
1
REMOTE: Failure is unlikely to occur
No evidence (i.e. work order) of prior occurrence; staff unaware of
it occurring on any similar piece of equipment.
2
LOW: Relatively few failures
Evidence (i.e. work order) of prior occurrence; staff aware of this
occurring on a similar piece of equipment, but not on the specific
equipment being analyzed, and the conditions resulting in the
previous failure do not exist in this case.
4
MODERATE: Occasional failures
Evidence (i.e. work order) of this failure mechanism with
occasional occurrence; staff aware that this failure mechanism
has occurred several times in the past.
8
HIGH: Repeated failures
Evidence (i.e. work order) of prior repeated occurrences; staff
aware that this failure mechanism has occurred many times in the
past.
10
VERY HIGH: Failure is almost inevitable
Evidence (i.e. work order) of continuous occurrence; staff aware
that this failure mechanism has occurred many times in the past.

13. Failure Effects
• The consequences of a
functional failure of an installed
asset. Failure effects are usually
described in terms of impact on
the asset, process, production,
and safety or environmental
issues.
Each failure mode may have more than one failure
effect. Identify all applicable failure effects for each
failure mode by inserting the proper weighting factor in
the appropriate column.

14. Failure Effects
FAILURE
CODE
DESCRIPTION
WEIGHTING
FACTOR
A FIRE / EXPLOSION 10
B TOTAL REFINERY SHUTDOWN 10
C HHC / FLAMMABLE SUBSTANCE RELEASE 10
D ENVIRONMENTAL EXCEEDANCE 10
E PLANT SHUTDOWN 8
F UNIT SHUTDOWN 7
G THRO'PUT REDUCTION (>5 %) 7
H THRO'PUT REDUCTION (<5 %) 5
I POWER IMPORT 5
J PLANT / UNIT UPSET 4
K LOSS OF REDUNDANCY 4
L ENERGY LOSS 4

15. Cost-to-Repair
• Preparer shall use best judgement or
component repair knowledge for this
estimate (Item L). Refer the Table
for the CTR value.
Cost to Repair
WEIGHTING FACTOR REPAIR COST
1 Minimal to moderate repair costs
3 Moderate to high repair costs
5 High to excessive repair costs

16. Determination of Critical Asset
Ranking
To determine the equipment criticality, list
out all the equipment's in the ascending form
depending upon their RPN value calculated
through failure mode criticality analysis
Prepare a bar chart using FEMA NO: in the
x axis and the risk priority no. in the y axis
Identify/classify the equipment's under three
categories viz. Most critical, critical and least
critical in the above chart.

17. EQUIPMENT CRITICALITY RANKING
0
100
200
300
400
500
600
700
800
900
H S V F T U E I P Z O Y A N X M B G C R K Q D L J W
FMEA No.
Criticality
Rank
Most Critical
Less Critical
Least Critical

18. Identification of applicable CD and
TD PM Task
1 List out the entire CD and TD preventive
maintenance task for the particular type of
equipment from the available sources.
2 Based on Equipment Criticality Ranking of
the equipment the required CD and TD PM tasks
shall be selected.
3 If one task eliminates more number of
failure modes that task shall also be included in
applicable CD and TD PM tasks.
1/2

19. 4 If the risk priority number of a particular
failure mode is very high the task that
eliminates the failure mode shall also be
included in applicable CD and TD PM tasks.
5 Based on equipment history the task
performed frequently on a particular type of
equipment shall also be included in
applicable CD and TD PM tasks.
6 The task need to be performed on
particular type of equipment to meet statutory
requirement shall also be included in
applicable CD and TD PM tasks.
Identification of applicable CD and
TD PM Task
2/2

20. FMEA Benefits
‫٭‬ Improves the quality, reliability & safety of the
products, or service.
‫٭‬ Generate input data for use in system safety and
maintainability analysis
‫٭‬ Reduces product development time and costs.
‫٭‬ Systematic approach to classifying failures
‫٭‬ Identifies all possible failure modes and their
effects on objectives, personnel, system
‫٭‬ Helps error identification and prevention
‫٭‬ Helps establish the forum for defect prevention
‫٭‬ Helps define the corrective action
‫٭‬ Helps determine the redundancy of the system

21. A B C D E F G H I J K L
PRIMARY ELEMENT
1 Impulse line take -off leakage 4 4 1 16 16
2 Impulse line choked 1 4 1 4 4
3 Impulse line steam tracing failure
SECONDARY ELEMENT
4 Micro Switch unit failure 1 4 3 12 12
5 Switch Repeatability failure 2 4 5 40 40
6 Calibration Setting drift 4 4 1 16 16
7 Switch mechanism malfunction 1 4 5 20 20
8 Switch cable termination/block fault 2 4 1 8 8
Branch Cable
9
Cable fault due to improper cable
glanding 1 4 3 12 12
10 Cable fault due to physical damage 1 4 3 12 0
Multi-Core cable fault
11 Cable fault due to physical damage 1 4 5 20 0
12
Cable termination fault at Marshall
Rack 1 4 1 4 4
13
Cable termination fault at Barrier
Rack 2 4 1 8 8
14 Cable termination fault at PLC opto-
coupler side 1 4 1 4 4
Switch Power supply
15 Barrier failure 2 4 3 24 24
16 Fuse blown at Power distribution
Unit due to earthing fault 1 4 1 4 4
204 172
CTR Ranking
PRESSURE SWITCH (TRIP) ---- UNIT/PLANT UPSET
Coverage
Effect
Sl.No. Failure mode LOF

22. Failure mode
A B C D E F G H I J K L
PRIMARY ELEMENT
1
Impulse line take -off
leakage 4 7 1 28 28
2 Impulse line choked 1 7 1 7 7
3
Impulse line steam
tracing failure
SECONDARY
ELEMENT
4
Micro Switch unit
failure 1 7 3 21 21
5
Switch Repeatability
failure 2 7 5 70 70
6
Calibration Setting
drift 4 7 1 28 28
7
Switch mechanism
malfunction 1 7 5 35 35
8
Switch cable
termination/block fault 2 7 1 14 14
Branch Cable
9
Cable fault due to
improper cable
glanding 1 7 3 21 21
10
Cable fault due to
physical damage 1 7 3 21 0
Multi-Core cable fault
11
Cable fault due to
physical damage 1 7 5 35 0
12
Cable termination fault
at Marshall Rack 1 7 1 7 7
13
Cable termination fault
at Barrier Rack 2 7 1 14 14
14 Cable termination fault
at PLC opto-coupler
side 1 7 1 7 7
Switch Power supply
15 Barrier failure 2 7 3 42 42
16 Fuse blown at Power
distribution Unit due to
earthing fault 1 7 1 7 7
357 301
Coverage
PRESSURE SWITCH (TRIP) ---- THRU'PUT RDn.
Ranking
Sl.No. LOF
Effect
CTR

23. Sl.No.
Failure
mode
FEMA
VALUE
Inspect
the
Pressure
take-off
point
/
impulse
line
leakage
Check
for
any
remote
seal
puncher/any
scratch
mark
on
the
diaphragm
Check
for
any
physical
damage
happened
at
capillary
side
Check
for
Switch
enclosure,
and
its
cable
glanding
healthiness.
Check
Switch,
Jn.
Box
cable
glandings
and
its
Gasket
to
avoid
water
entry
Check
for
Inst.
Cable
tray
and
Jn.
Box
external
painting
condition
and
its
rain
hood
fixation
Check
for
loop
termination
tightness
from
field
S/W
to
FPR
Check
for
S/W
actuation
to
its
calibrated
set
point.
Shop
Service
/
calibrating
the
switch
/
S/d
Check
for
proper
Barrier
grounding
termination
&
its
power
supply
PRIMARY ELEMENT PS1 PS2 PS3 PS4 PS5 PS6 PS7 PS8 PS9 PS10
1 Impulse line take -off leakage 16 16
2 Impulse line choked 4 4
3
Impulse line steam tracing
failure
SECONDARY ELEMENT
4 Micro Switch contact failure 12 12 12 12 12
5 Switch Repeatability failure 40 40 40 40 40
6 Calibration Setting failure 16 16 16 16
7 Switch mechanism malfunction 20 20 20 20 20 20 20 20
8
Switch cable termination/block
fault 8 8 8 8 8 8
Branch Cable
9
Cable fault due to improper
cable glanding 12 12 12
10
Cable fault due to physical
damage 12 12
Multi-Core cable fault
11
Cable fault due to physical
damage 20
12
Cable termination fault at
Marshall Rack 4 4 4
13
Cable termination fault at
Barrier Rack 8 8 8
14 Cable termination fault at PLC
opto-coupler side 4 4 4
Switch Power supply
15 Barrier failure 24 24 24
16 Fuse blown at Power
distribution Unit due to earthing
fault 4 4 4
204 16 60 60 68 52 12 44 144 96 28
PRESSURE SWITCH (TRIP) --- UNIT/PLANT UPSET

24. Sl.
No.
Failure
mode FEMA
VALUE
Inspect
the
Pressure
take-
off
point
/
impulse
line
leakage
Check
for
any
remote
seal
purchase/any
scratch
mark
on
the
diaphragm
Check
for
any
physical
damage
happened
at
capillary
side
Check
for
Switch
enclosure,
and
its
cable
glanding
healthiness.
Check
Switch,
Jn.
Box
cable
glandings
and
its
Gasket
to
avoid
water
entry
Check
for
Inst.
Cable
tray
and
Jn.
Box
external
painting
condition
and
its
rain
hood
Check
for
loop
termination
tightness
from
field
S/W
to
FPR
Check
for
S/W
actuation
to
its
calibrated
set
point.
Shop
Service
/
calibrating
the
switch
/
S/d
Check
for
proper
Barrier
grounding
termination
&
its
power
supply
PS1 PS2 PS3 PS4 PS5 PS6 PS7 PS8PS9 PS10
1
Impuls
e line
take -
off
leakag
e 16 16
2
Impuls
e line
choke
d 4 4
Impuls
e line
steam
PRESSURE SWITCH (TRIP) --- UNIT/PLANT UPSET
PRIMARY ELEMENT

25. Sl.N
o.
Failure mode
FEMA
VALUE
Inspect
the
Pressure
take-
off
point
/
impulse
line
Check
for
any
remote
seal
purchase/any
scratch
mark
on
the
Check
for
any
physical
damage
happened
at
Check
for
Switch
enclosure,
and
its
cable
Check
Switch,
Jn.
Box
cable
glandings
and
its
Gasket
to
avoid
water
Check
for
Inst.
Cable
tray
and
Jn.
Box
external
painting
condition
and
its
Check
for
loop
termination
tightness
Check
for
S/W
actuation
to
its
calibrated
set
point.
PRIMARY ELEMENT PS1 PS2 PS3 PS4 PS5 PS6 PS7 PS8
1
Impulse line take
-off leakage 16 16
2
Impulse line
choked 4 4
3
Impulse line
steam tracing
failure
SECONDARY
ELEMENT
4
Micro Switch
contact failure 12 12 12 12
5
Switch
Repeatability
failure 40 40 40 40
6
Calibration
Setting failure 16 16 16
7
Switch
mechanism 20 20 20 20 20 20 20
8
Switch cable
termination/bloc
k fault 8 8 8 8 8
Branch Cable
9
Cable fault due
to improper
cable glanding 12 12 12
PRESSURE SWITCH (TRIP) --- UNIT/PLANT UPSET

26. 8
Switch cable
termination/block
fault 8 8 8 8 8
Branch Cable
9
Cable fault due to
improper cable
glanding 12 12 12
10
Cable fault due to
physical damage 12 12
Multi-Core cable
fault
11
Cable fault due to
physical damage 20
12
Cable termination
fault at Marshall
Rack 4 4 4
13
Cable termination
fault at Barrier Rack 8 8 8
14 Cable termination
fault at PLC opto-
coupler side 4 4 4
Switch Power
supply
15 Barrier failure 24 24
16 Fuse blown at
Power distribution
Unit due to earthing
fault 4 4
204 16 60 60 68 52 12 44 144

27. A B C D
a) If impulse line / take-
off point noticed for any
leakage inform the
supervisor.
Inst
b) End fitting connection
damage/ leakage being
noted inform the
supervisor
Inst
a) Field Switch cover
fixation not proper
inform the supervisor
Inst
b) Switch cable glanding
fault/damage noticed
inform the supervisor
Inst
a)All Stages of cable
termination to be
tightened.
Inst
b)Drift in actuation
setpoint, recalibrate the
instrument to the
required set point
Inst
c)Any abnormal inst.
Performance report to
the supervisor for
corrective action
Inst
PS8-Check for S/W
termination healthiness
and its response for its
calibrated set point.
C
Critical - PlantUnit Thru'put Reduction
Semi-Critical - Unit Upset
Super Critical - PlantUnit shutdown
Non-Critical - Alarm
B
D
PRESSURE SWITCH PM SCHEDULE
PS1) Inspect the
Pressure take-off point /
impulse line leakage -
Visual check
6
MONTH
PS4) Check for Switch
enclosure, and its
cable glandings
healthiness - Visual
check
6
MONTH
Responsible
DESCRIPTION
6
MONTH
CATEGORY
A
6
MONTH
1
YEAR
1
YEAR
SD
/
1
YEAR
SD/
2
YEAR
Instruction
6
MONTH
6
MONTH
FREQ
6
MONTH
6
MONTH
Activity

28. Routines Activity Details Responsible
Daily Activity: Nil
Weekly Activity : Nil
Monthly Activity
a) Condition the
impulse line
Inst
b) Proper action to be
taken for end fitting
connections if any
damage being noted
Inst
a) Fix the Switch
cover properly
Inst
b) Close the Jn. Box
door with proper
fixing screws
Inst
a) Proper cable
glanding to the
Switch & Jn.Box to
be done if needed
Inst
b) Replace the Jn.
Box Gasket if
needed/damage
observed
Inst
PRESSURE SWITCH PM ACTIVITY
IP1) Observe for
Impluse line
condition and its
end fittings
IP2) Check for
Switch enclosure,
Jn. Box cover &
door fixed properly
IP3) Check Switch,
Jn. Box cable
glandings and its
Gasket to avoid
water entry
1/2

29. Routines Activity Details Responsible
IP4) Check for Inst.
Cable tray and Jn. Box
external painting
condition and its rain
hood fixation
a) Report any damage
noticed towards cable
tray / Junction Box Inst
IP6) Check for S/W
actuation to its
calibrated set point
a) Any drift from set point
corrective action to be
done
Inst
a) Any malfunction noted
service the switch
Inst
b) Repeatability problem
replace the switch
Inst
a) All Stages of Cable
terminations to be
tightened if any loose
connections noted
Inst
b) Barrier grounding
terminal connections and
its power supply to be
inspected, any
abnormality report to the
supervisor
Inst
PRESSURE SWITCH PM ACTIVITY
Yearly Activity
IP7) Shop Service /
calibrating the switch /
S/d
IP5) Check for loop
termination tightness
from field S/W to FPR
Half-Yearly Activity

30. S.NO
TAG NO
CATEGORY
Manhours/Yr
FMEA
FMEA
COVERED
FMEA
%
COVERAGE
1 76X
V411 C 1.17 256 224 87.5
2 76X
V412 C 1.17 256 224 87.5
3 76X
CV413 C 1.50 256 224 87.5
4 76X
CV414 C 1.50 256 224 87.5
5 76X
CV415 C 1.50 256 224 87.5
6 76X
Y411 C 0.17 240 196 81.67
7 76X
Y412 C 0.17 240 196 81.67
8 76ZSL411 C 0.17 276 244 88.41
9 76ZSL412 C 0.17 276 244 88.41
10 76ZSL413 C 0.17 276 244 88.41
11 76ZSL414 C 0.17 276 244 88.41
12 76ZSL415 C 0.17 276 244 88.41
13 76PT411 C 0.67 466 434 93.13
14 76PT403 A 4.67 784 728 92.86
15 LHH19276 A 8.67 448 392 87.5
16 THH19176 A 4.67 721 560 77.67
26.70 87.13
76 C 31 ADSORBER UNIT