Criticality Analysis 31 01 08

7/28/2019 Criticality Analysis 31 01 08

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SCA

System / Equipment / Spare Parts

Criticality Analysis(SCA)

Dr. Att ia Hus sien Gomaa

Maintenance Engineer ing Consu ltant

2008

Engin eer ing service - American Univers i ty in Cairo (AUC)


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SCA 2System Cri t icality Analys is - Dr. Att ia Gomaa - 2007

Risk / Crit ical i ty Parameters :

Safety (HSE and security) effect

Process effect (production losses)

Standby availability (6/5, 5/5, 4/5, 3/5, 2/5)

Costs (operation and maintenance)

Site/ Train / Sys tem / Unit / Equipment:

Item / Maintenance / Spare Parts:

Mean time to/bet. failure (MTTF or MTBF)

Mean time to repair (MTTR)

Work order priority

Item Cost


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Rule 80/20:

Level

Level description Total Value % Total Item %

A Cri tical >= 80 = 80% Value)


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ABC Inventory Classification

0

20

40

60

80

100

120

0 10 20 30 40 50 60 70 80 90 100

Percentage of Items

Pe

rcentageo

fDollars


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ABC Classification System

A-Very important

B

medium important

C- least important

Annual$ valueof items

A

B

C

High

Low

Few Many

Number of Items


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ABC Classification

A - Receive tight control

(Continuous Control)

Top 10-20%

B - Receive relaxed control(Periodic Control) - I

Next 30%

C- Receive minimal control(Periodic Control) - II

Last 50-60%


7/33SCA 7System Cri t icality Analys is - Dr. Att ia Gomaa - 2007

System #1:Safety firs t

Level Description Example

A Major effect on HSE F ire f ighting pump

B Major effect on Process

= H igh down time cost

Feed crude oil pump

C Normal effect on HSENormal effect on process

Without standby

Water feed pump

D Normal effect on HSENormal effect on process

With standby

Water feed pump

Case: Equipment Criticality Systems



System #2:Equipment List HSE Process Standby Level

Gas condensate pump Major Major Without A+

Feed crude oil pump Medium Major With B

Export Pump Major Major With A

Sump Pit Pump (vessels) Major Major With A

Fire fighting pump Major Minor With A

Water feed pump Normal Medium With D

Instrument Air Compressor Major Major With A

Stand By Generator (Diesel) Major Major Without A+

Ac t iv i ty l is t

Material lis t

Manpower l ist

S t #3



System #3:

Category Criticality Consequences

Safety

(HSE)

1No potential for injury, pollution, fire or effect on

safety systems

2No effect on safety systems controlling process and no

potential for fatalities, moderate or large pollution or

fire in classified areas

3Potential for fatalities, moderate or large pollution and

fire in classified areas.

Production

(P)

1 No effect on production

2 Brief stop in production < 1 hour or reduced product

3 Production shutdown > 4 hours

Cost ( C )

1 Insignificant consequential cost < 1,000 USD

2 Moderate consequential cost > 1,000 < 15,000 USD

3 Substantial consequential cost > 15,000 USD

(1) Low criticality. (2) Medium criticality. (3) High criticality.



Part list:Partclassification(Rule 80/20)

Top 2 Parts

Based on this information,classify & discuss these

parts.

Item

Code

Unit price

($)

Annual Demand

(unit)

S11 10 1000

S12 40 100

S13 100 10

S14 30 200

S15 20 500

S16 200 600

S17 100 40

S18 55 950S19 80 30

S20 100 20



Item

Code

Unit

price ($)

Annual

Demand

(unit)

Annual

Value $

Cumulative

value $

Cumulative

%

Item

Level

S16 200 600 120000 120000 56.7% A1AS18 55 950 52250 172250 81.4% A2

S11 10 1000 10000 182250 86.1% B1

B

S15 20 500 10000 192250 90.8% B2

S14 30 200 6000 198250 93.7% B3

S12 40 100 4000 202250 95.6% C1

C

S17 100 40 4000 206250 97.4% C2

S19 80 30 2400 208650 98.6% C3

S20 100 20 2000 210650 99.5% C4

S13 100 10 1000 211650 100.0% C5

Total 211650


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Turbine Failure listduring three years

Part

Code

Number of

failures

MTTR

(hour)P11 2 4

P12 2 15

P13 19 1

P14 11 14

P15 2 21

P16 12 12

P17 17 1P18 10 5

P19 11 12

P20 4 3

Failureclassification(Rule 80/20)

Top 4 failures

Based on this information,classify & discuss these

items.


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Part

CodeNumber

of

failures

MTTR

(hour)Total

downtime

hours

Cum.

DTCum. % Item

Level

Level

P14 11 14 154 154 25.3% A1

A

P16 12 12 144 298 49.0% A2

P19 11 12 132 430 70.7% A3

P18 10 5 50 480 78.9% A4

P15 2 21 42 522 85.9% B1

B

P12 2 15 30 552 90.8% B2

P13 19 1 19 571 93.9% B3

P17 17 1 17 588 96.7% C1

CP20 4 3 12 600 98.7% C2P11 2 4 8 608 100.0% C3

Total 608


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Weigh t Facto r:

Part Code Number of

failures

60%

MTTR

(hour)

40%

Value Level

P14 11 14 12.2 A1

A2

A3

A4

P16 12 12 12.0

P13 19 1 11.8

P19 11 12 11.4

P17 17 1 10.6 B1

B2

B3P15 2 21 9.6

P18 10 5 8.0

P12 2 15 7.2 C1C2

C3P20 4 3 3.6

P11 2 4 2.8


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Case:

Part Code Number offailures

MTTR(hour)

HSEeffect

(1 to 4)

Repaircost

(1 to 4)

Deliverytype

(1 to 3)

P11 2 4 1 2 1

P12 2 15 2 1 2

P13 19 1 4 4 3

P14 11 14 3 3 2

P15 2 21 2 2 1

P16 12 12 4 4 3

P17 17 1 2 3 1

P18 10 5 1 3 1

P19 11 12 1 4 3

P20 4 3 4 1 2

Based on this information, classify & discuss these parts.


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Part Code (1)HSE effect

(1 to 4)

(2)Total

Downtime(A,B,C)

(3)Repaircost

(1 to 4)

(4)Delivery

type(1 to 3)

Level

P11 1 C3 2 1P12 2 B2 1 2

P13 4 B3 4 3

P14 3 A1 3 2

P15 2 B1 2 1P16 4 A2 4 3

P17 2 C1 3 1

P18 1 A3 3 1

P19 1 A4 4 3P20 4 C2 1 2


4: Critical 3: Major 2: Medium 1: Minor


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Case:

PartCode

(1) 50%HSE effect

(1 to 4)

(2) 25%Total

Downtime

(A,B,C)

(3) 15%Repaircost

(1 to 4)

(4) 10%Delivery

type

(1 to 3)

RPN Level

P11 1 1 2 1

P12 2 2 1 2

P13 4 2 4 3

P14 3 4 3 2P15 2 2 2 1

P16 4 4 4 3

P17 2 1 3 1

P18 1 3 3 1P19 1 3 4 3

P20 4 1 1 2



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PartCode

(1) 50%HSE effect

(1 to 4)

(2) 25%Total

Downtime(A,B,C)

(3) 15%Repair cost

(1 to 4)

(4) 10%Delivery

type(1 to 3)

RPN Level

P16 4 4 4 3 3.9 A1P13 4 2 4 3 3.4 A2

P14 3 4 3 2 3.15 A3

P20 4 1 1 2 2.6 B1

P19 1 3 4 3 2.15 B2P15 2 2 2 1 1.9 C1

P12 2 2 1 2 1.85 C2

P17 2 1 3 1 1.8 C3

P18 1 3 3 1 1.8 C4P11 1 1 2 1 1.15 C5

A: Major B: Medium C: Minor


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Risk = Severity x Probability

Risk = Consequencex Frequency

Risk Level:

X

Risk :Any future bad news (objective or subjective)

Severity :Harm or damage caused by a hazard

Probability :Likelihood that the harm is realized


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Risk = Severity x Probability

Risk = Consequencex Frequency

Cri tical i ty Assessment: (Risk Matrix )

(1) Low (2) Medium (3) HighSeverity

(1) Low

(2) Medium

(3) High

Probability

(1 * 1) = 1

(3 * 3) = 9

(2 * 2) = 4

(2 * 1) = 2

(1 * 2) = 2

(3 * 1) = 3

(1 * 3) = 3

(3 * 2) = 6

(2 * 3) = 6


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Consequence or Sever ityProbability

Or

Frequency

(3)

High

(2)

Medium

(1)

Low3

M

2

L

1

L

(1) Low:

>2 y

6

H

4

M

2

L

(2)Medium:

1-2y

9

S

6

H

3

M

(3) High:


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SeverityProbability

orFrequency (3)

High

(2)

Medium

(1)

Low

3

N

2

N

1

N

(1) Low:

Y

6

C

4

N

2

N

(2) Medium:

6m-1y

9

C

6

C

3

N

(3) High:


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Severity

5 4 3 2 1

>6 f/y 5 H H H M L

5-6 f/y 4 H H M M L

3-4 f/y 3 H M M L L

1-2 f/y 2 M M L L L


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People Assets Environ-ment

Repu-tation

Severity

0

1

2

3

4

5

No injury

or damage

to health

Slight injury

or healtheffects

Minor injury

or health

effects

Major injury

or health

effects

Single fatality

or permanent

total disability

Multiple

fatalities

No

damage

Slight

damage

Minor

damage

Local

damage

Major

damage

Extensive

damage

No

effect

No

impact

Slight

effect

Slight

impact

Minor

effect

Minor

impact

Localised

effect

Consider-

able

impact

Major

effectNational

impact

Inter-

national

impact

Massive

effect

Never heard ofin

EP industry

A

LowLow

MediumMedium

HighHigh

Hasoccurred in

EP industry

B

Has occurred inthe audited OU

C D

Happensseveral t imes a

year in the

audited OU

E

Happensseveral t imes a

year in the

audited facility

SeriousSerious

RISK ASSESSMENT MATRIX (HSE effect)

Frequency

System #4:


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Risk Matrix

Risk Matrix(Risk probability * consequences)

Probability

Consequence I

Frequent

II

Probable

III

Occasional

IV

Remote

V

Improbable1

CatastrophicA A A B B

2

CriticalA A B B C

3Moderate

A B B C C

4

NegligibleB C C C C

S #5


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Risk Assessment Matrix

U.S. Army Field Manual 3-100.12.

EExtremely high risk HHigh risk

MMedium risk LLow risk

Severity

Probability

Frequent Likely Occasional Seldom Unlikely

Catastrophic E E H H M

Critical E H H M L

Marginal H M M L L

Negligible

M L L L L

System #5:


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Class Environment Safety Production

1 Small effect No injury No effect

2 Minor effect Minor

injury

Minor effect

Less

3 Local effect Major

injury

Local effect

Medium

4 Major effect Single

fatality

Major effect

High

5 Massive effect Multiple

fatality

Massive

effect Ver high

Time Interval between Failures

Consequence AT >= 10 Years

B

5 =< T < 10

Years

C

2 =< T < 5

Years

D

0.5 < T < 2

Years

E

T


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Level Potentialimpact

Definition

1 Small

effect

No disruption to operation, no operational upset or no

damage to assets. (total loss value less than US$ xxxxx)

2 Minoreffect

Brief disruption, minor operational upset or minordamage to assets. (total loss value less than US$xxxx)

3 Localeffect

Partial shutdown, moderate operational upset or moderatedamage to assets (total loss value less than US$ X Million)

4 Majoreffect

Partial operation loss, major operational upset or major

damage to assets (total loss value less than US$ xx Million)

5 Massiveeffect

Substantial or total loss of operations, damagecausing major loss of containment or damage toessential assets (total loss value in excess of US$ xxMillion)


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Cat Potential

impact

Definition

1 Small effect Small effectVery Local environmental damage. Within

the fence and within systems. No change in theenvironment.

2 Minor effect Minor effectContamination. Damage sufficiently large

to attack the environment. Single exceedance of

statutory or prescribed criterion.. No permanent effect

on the environment.

3 Local effect Localised effect Limited loss of discharges of known

toxicity.

4 Major effect Major effect Severe environmental damage. The

company is required to take extensive measures to

restore the contaminated environment to its original

state.

5 Massive effect Massive effectPersistent severe environmental damage

or severe nuisance extending over a large area..


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Cat Potential

impact

Description

1 Small injury Small effect or sl ight injury or health eff ects(including

first aid case and medical treatment case) - Not affecting

work performance

2 Minor injury Minor injury or health effects (Lost Time Injury)

Affecting work performance, such as restriction to

activities (Restricted Work Case) or a need to take a few

days to fully recover (Lost Workday)..

3 Major injury Major injury or health effects (including Permanent

Partial Disability) Affecting work performance in the

longer term, such as a prolonged absence from work.

4 Single fatality Single fatal ity

From an accident or occupational illness5 Multiple

fatality

Multiple fatalities- From an accident or occupational

illness


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SCA 33S t C i t i l i t A l i D Att i G 2007

Cat Time Interval Description

A 10 years or more Interval between failures is 10 years ormore

B 5 =< T < 10 Years Interval between failures is 5 years or more

C 2 =< T < 5 Years Interval between failures is 2 years or more

D 0.5 < T < 2 Years Interval between failures is more than 0.5Years

E 0.5 year or less Interval between failures is 0.5 years or less

Documents

Criticality Analysis 31 01 08