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Hazard IdentificationFMEA HAZ P
Prof. Ir. Dr. Mohd Sobri Takriff
Dept. of Chemical & Process Engineering,
FMEA
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What is FMEA?
FMEA is an acron m that stands forFailure Modes and Effects Analysis
Identifies the potential failure of a systemand its effects
that would eliminate the chance ofoccurrence
Documents the potential failures
1963 1965 1975 1977 1980 1986 1990 1996 1998
NASA Aeronautics Nuclear Presentation Standard- Use in Use in Further Increasedand space Engi- of the FMEA ization in the auto- the different development use in the
travel neering to the auto- Germany motive branches of to the system automotive
The History of the FMEA
motive industry industry FMEA industryindustry (first of all, (since 94(Ford) suppliers) at AOAG)
QS 9000
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FMEA
Oriented towards e ui ment rather thanprocess
Paticularly suited for mechanical and electricalsystems
FMEA systematically
on that system
determines the significance of each failure modewith regard to the system's performance
Applications & Benefits?
May be applied at various stages
Design
Process (operation)
Service and Maintenance
Improvements in: a e y
Quality
Reliability
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FMEA - Methodology
define the s stem to be evaluated
establish the level of analysis
Failure Analysis identify failure modes, causes and consequences
as well as design and operating provisions againstsuch failures
Reporting
FMEA System Definition
define the extent of the s stem to beanalyzed
usually performed in relatively small steps
Requires analysts / personnels with aknowledge of the system
system and their performance requirements
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FMEA Level of Analysis
based on the functional structure of a s stem
the failure modes are expressed as failure toperform a particular subsystem function
primary function is that for which the subsystemwas rovided
secondary function is one which is merely aconsequence of the subsystem's presence
FMEA Analysis of Failures
remature o eration
failure to operate when required
intermittent operationfailure to cease operation when required
loss of output or failure during operation
degraded output
etc
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FMEA Analysis of Failures
Based on Failure modes
looks at the likely causes and the effects on boththe components and the system
consideration is given to the relative importance ofthe effects and the sequence
safeguards against such failures and methods ofdetecting them are then examined
FMEA - Reporting
identif the most si nificant failures in termsof their effects on the overall system
decide whether or not the existing safeguardsand detection devices are adequate
more detailed analysis on the weak link
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FMEA - Reporting
No standard re ortin format t icall covers The unit/system
Failure mode
Consequence of failure
Symptoms
safeguards
Example 1Household Water Supply system
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FMEA Household water supply system
Water Supp y System FMEA
No Component
DescriptionFailure mode Failure effect(s) Symtoms
Safe
GuardsActions
1 Kitchen Tap Fails open Kitchen Flooded
Water
continuously
flowing out-
Install flow
control valve
2Inlet pipe
(2 in PVC)Blocked Water Tank Dry
No water at
kitchen tap -
Install waterfilter
Clean filter
periodically
Example 1Household Water Supply system
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Failure Mode Effect Analysis(FMEA)
CRITICALITY ANALYSIS
Criticality is defined in the same way as risk - thatis, a combination of the severity of an effect andthe probability or expected frequency
simplest approach requires a form of ranking or
effect / consequence
frequency
Failure Mode Effect Analysis(FMEA)
of the following categories loss of mission due to inability of equipment to
perform
economic loss due to lack of output orfunction
damage to plant or third party property
injury to operating personnel or the public
death to operating personnel or the publicand/or significant damage to the environment
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Failure Mode Effect Analysis(FMEA)
order or severity)
catastrophic - may cause death or totalsystem loss
critical- may cause severe injury or
major - may cause some injury or damage
minor - requires unscheduled maintenance.
Failure Mode Effect Analysis(FMEA)
uantification of fre uenc de ends on thedata available and may again be a simpleranking, such as one depending on failure
probability during the operating time interval extremely unlikely
remote
ccas ona
reasonably frequent
frequent
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Failure Mode Effect Analysis(FMEA)
extremely unlikely - 0.001
remote - between 0.001 and 0.01
occasional- between 0.01 and 0.1
- .and 0.2
frequent - 0.2.
Failure Mode Effect Analysis(FMEA)
5 A C C D D
4 A B C C D3 A B B C C
2 A A B B C
1
1 2 3 4 5
A B C DACCEPTABLE UNACCEPTABLE
Threshold value = 10
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FMEA
-
reduce probability that the cause offailure will result in the failure mode
reduce severity of failure by redesignor add rotection redundanc
increase probability of detection
HAZOP
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HAZOP
OPerability studies
The term 'HAZOP' originated in ICI andfirst appeared in the literature in the
early 1970s
HAZOPSkelton, B, 1997
, , ,the process and engineering intentions of new andexisting facilities to assess the hazard potential of mal-
operation or mal-function of individual items of equipment and the consequential effects
e s, ,
HAZOP is formal, systematic examination of aprocessing plant in order to identify hazards, failuresand operability problems, and assess theconsequences from such mal-operation
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WHY DO HAZOP??
Generates a list of identified roblemsusually with some suggestions forimprovement of the system
improves safety, reliability and quality bymaking people more aware of potential
.
help to sort out loopholes and inconsistenciesin procedures and force plant personnel toget their instructions up to date
HAZOP
Basic hiloso h if a process operates within its intended
design philosophy then undesired
hazardous events should not occur
The ob ective of a HAZOP mainly to identify how process deviations
can be prevented or mitigated to minimizeprocess hazards
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Basic Ideas of HAZOP
to stimulate the ima ination of a reviewteam, including designers and operators, in asystematic way so that they can identifypotential hazards in a design
in order to consider all the possible ways thatprocess and operational failures can occur
HAZOP
recommend necessary changes to asystem to meet company risk guidelines
recommend procedures or changes fore m na ng or re uc ng e pro a y ooperating deviations.
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HAZOP
a lication at the correct sta e in aproject means that problems areidentified and can be rectified duringdetailed design.
material for inclusion in the plantoperating instructions
HAZOP Terminology
Desi n intent
the way in which the plant is intended to operate.
Deviation
any perceived deviations in operation from thedesign intent. Cause- the causes of the perceiveddeviations.
Consequence
the consequences of the perceived deviations
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Hazop TerminologySafeguards
consequences of the perceived deviations and to informoperators of their occurrence
Actions the recommendations or requests for information made by
the study team in order to improve the safety and/or
operability of the plant.
u e wor s simple words used to qualify the intent and hence discover
deviations.
Parameters basic process requirements such as 'flow', 'temperature',
'pres-sure' and so on.
HAZOP COMPONENTS
Procedure
Guide words
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Hazop Team
normall com rises between four and ei htmembers, each of whom can provide knowledge and
experience appropriate to the project to bestudied
efficient and allow each member to make acontribution, whilst containing sufficient skillsand experience to cover the area of studycomprehensively
Hazop Team
Hazop team:
those with detailed technical knowledge ofthe process;
those with knowledge and experience of
chair and report upon technical meetings
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Hazop Team
t ical member of a Hazo team
chairman or team leader
secretary
process design engineer
control engineer
operations specialist
project engineer
Other specialists may be consulted or beavailable for specific points
Hazop Team
selected for his or her ability to effectivelylead the study
should have sufficient seniority to give thestudy recommendations the proper level of
knowledge and experience of the Hazoptechnique
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Hazop Team
should have a technical appreciation of theproject and be familiar with the HAZOPtechnique
technical members usually part of the project design team
Hazop PROCEDURE1. Begin with a detailed flow sheet. Break the flow
eg the reactor area might be one unit, and the storagetank another. Select a unit for study.
2. Choose a study node (vessel, line, operatinginstruction).
3. Describe the design intent of the study node. eg example, vessel V-I is designed to store the benzene
feedstock and provide it on demand to the reactor.
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Hazop PROCEDURE4. Pick a process parameter:
,
level,
temperature,
pressure,
concentration,
pH,
viscosit
power,
Inert
etc
Hazop PROCEDURE
5. Apply a guide word to the process parameter to.
NO
MORE
LESS REVERSE
etc
6. If the deviation is applicable, determine possiblecauses and note any protective systems.
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Hazop PROCEDURE7. Evaluate the consequences of the
.
8. Recommend action what?
by whom?
b when?
Hazop PROCEDURE
9. Record all information.
10.Repeat steps 5 through 9 until allapplicable guide words have beenapplied to the chosen process
.
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Hazop PROCEDURE
11. Re eat ste s 4 throu h 10 until all a licableprocess parameters have been considered forthe given study node.
12. Repeat steps 2 through 11 until all studynodes have been considered for the givensection and roceed to the next section on the
flow sheet.
Hazop PROCEDURE
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Hazop GUIDE WORDSGuide words Meaning Comments
NO, NOT,
NONE
The complete negation of the
intention Quantitative decrease
No part of the design intention is achieved, but
nothing else happens.
MORE, HIGHER,GREATER
LESS, LOWERQuantitative increase
Applies to quantities such as flow rate and
temperature and toiattivities such as heating and
reaction.
AS WELL AS Quali ta tive increase
All the design and operating intentions e achieved
along with some additional activity, such as
contamination of process streams.
PART OF Qualitative decreaseOnly some of the design intentions are achieved,
some are not.
REVERSE The logical opposite of
Most applicable to activities such as flow or chemical
reaction. Also applicable to substances, for example,
po son nstea o ant ote.
OTHER THAN Complete substi tut ionNo part of the original intention is achieved - the
original intention is replaced by something else
SOONER THAN Too early or in the wrong order Applies to process steps or actions.
LATER THAN Too late or in the wrong order Applies to process steps or actions.
WHERE ELSE In additional locationsApplies to process locations, or locations in operating
procedures.
Hazop Worksheet
HAZARDANDOPERABILITY STUDYREPORTProject Title:
Project Number; Date:
P&ID Number: Chairman:
Line Number: Study Team:
Guideword
Deviation Cause Consequences Safeguards
Action
Number By DetailsReply
Accepted
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Hazop WorksheetHAZOP ACTION SHEET
Project: Project no: Action no:
Action on: Date for reply:
Description:
Reply:
Review comments:
Accepted/rejected (Leader) Date:
Issued Returned Complete
Return completed form to:
Example 3Household Water Supply system
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Example 3Household Water Supply system
HAZARD AND OPERABILITYSTUDY REPORT
Project Title: household water supply system
Project Number; 2008-101 Date: 25 Oct 2008
Drawing Number: Myhome-101 Chairman: Mywife
Line Number: Line No 1 ( pipe from water tank
and kitchen tap)
Study Team: MyHusband, Maid, eldest son
Item:KitchenTap Paramter:FlowGUIDE
WORDSDEVIATIONS CAUSES CONSEQUENCES SAFEGUARDS ACTION REQUIRED
REVERSEWater flow
continuously
Valve (kitchen tap)
fails openKitchen flooded none
Install flow control
valve
NO No Flow Pipe BlockedNo water supply
to kitchennone
Install tank cleaning
system
LESS Low flowPipe partially
Blocked
Reduced ater
flow to kitchennone
Install tank cleaning
system
MORE
Example 3Household Water Supply system
HAZARD AND OPERABILITYSTUDY REPORT
Project Title: household water supply system
ro ect um er: - ate: ct
Drawing Number: Myhome-101 Chairman: Myhusband
Line Number: Line No 2 (main valve, pipe &
tank)
Study Team: Mywife, Maid, eldest son
Item:WaterTank Paramter:WaterSupplyGUIDE
WORDSDEVIATIONS CAUSES CONSEQUENCES SAFEGUARDS ACTION REQUIRED
MOREMore water than
tanks capacity
House owner forgot
to close water
supply valve
Water tank
overflow, house
flooded
none Install level control ler
NO No water Pipe blocked Tank dry none Install water filter
LessLow water level
in tank
Pipe partially
blocked
Low water
pressure to
bathroom and
kitchen
none Install water filter
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Example 3
Household Water Supply system
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