engineering reliability
DESCRIPTION
Ashraf S. Youssef, Ph. D., Senior Member ASQ, Quality Assurance ManagerTRANSCRIPT
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ENGINEERING RELIABILITY
Dr. Ashraf S. YoussefAssistant Professor QMS ConsultantAssistant Professor, QMS Consultant
Industrial Engineering Dept.Fayoum University
Course IntroductionWelcome!Welcome!Instructor introduction.Student introduction.
TEXT BOOKTEXT BOOKReliability Engineering: Fundamental and Applications, R. Ramakumar, Prentice Hall International, 1993.
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Learning ObjectivesUnderstand Reliability fundamentals.yRelation Between Quality and Reliability.Modeling Approach for Parallel and Serial Systems.Equipment Survival.Reliability Prediction MethodsReliability Prediction Methods.Reliability Testing.Maintainability Concept and Measure.Integrated Logistic Support.Replacement Models
Our Objective
You Enjoy While YouLearn
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Part ONE
Introduction toReliability Engineering
Definitions (1/2)
Reliability Quality maintained over time
Quality Meeting customer requirements
Quality Control Monitoring quality characteristics
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Definitions (2/2)
Quality Assurance
Set milestones to check quality in progress
Quality Auditing
Use the proper gages and measuring devices and procedures Auditing to check quality (Use sampling)
TQMSet necessary conditions for all production steps from entering raw materials to finish products
Relation between QC, QA, & TQM
TQM … Organization
QA … Business Processes
TQM … Organization
PoliciesProcedures
Responsibilities
LeadershipBusiness Results
EmployeesCulture
Difficult Time Soft
SPC … Product
On-lineOff-line
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Quality Dimensions
PerformanceFeatures
ReliabilityConformance Durability
Serviceability
Perceived Quality
ProductProduct
Source: Total quality and organization development by Lindsay and Petrick
Part TWO
Discrete Random Variables and
P b bilit Di t ib tiProbability Distributions
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Statistical OverviewP l tiPopulation
A large No. of N
Mean = µ
Standard Deviation = σ
Sample
A small No. of n
Sample Mean =
Sample Standard Deviation = s
X
Descriptive StatisticsCentrality Measures
ModeMedianMean
Dispersion MeasuresRangeRangeVarianceStandard DeviationCoefficient of Variation
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Accuracy & Precision
____________ ____________ ____________ ____________
____________ ____________ ____________ ____________
Example:Histogram
Freq.
6 9 13 17 21 25Weight
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Bernoulli Distribution
Set 1Set 2
Those two sets are:1. Mutually exclusive2. Union of the 2 sets represents the random space
Probability Calculations1. Probability of occurrence in the set 1 = P2. Probability of occurrence in the set 2 = q
P.d.f (X=x) = 1, if x є s1 0, if x є s2
Binomial Distribution (1/2)Is a repeating Bernoulli n times and measuring outcomes. s a epeat g e ou t es a d easu g outco esThe trials are:
Independent, each trial has only two outcomes.P.d.f xnxn
x qpxXP −== )()(Where P is the prob. Of outcome of the set 1Where q is the prob. Of outcome of the set 2
X is the variable observed and related to p
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Binomial Distribution (2/2)If x is a binomial random variable with parameters p
npxE == )(μ2
If x is a binomial random variable with parameters p and n then:
)1()(2 pnpxV −==σ
Example:
Each sample of air has a 10% of chance of containing a particular molecule. Assume the samples are independent with regard to the presence of the rare molecule. Find the probability that in the next 18 samples, exactly 2 contains the rare molecule. Also, calculate the expected value of the random variable x and the variancethe random variable x and the variance.
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Hyper Geometric Dist (1/2).Is a special case from binomial.pThe population N is known
P.d.f
)())(()( N
n
MNxn
MxxXP
−−==
Where N= size of population, n = Sample size, M is the objects that classified as successes, x = no. of success in the sample.
Hyper Geometric Dist (2/2).Let p=M/Np /
)( ==
Nand
npxEμ
)1
)(1()(2
−−
−==N
nNpnpxVσ
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Example:
A batch parts contains 100 parts from a local suppliers of a tubing and 200 parts from a supplier of tubing in the next state. If four parts are selected, at random without replacement, what is the probability they are from the local supplier, and what is the probability that at least one part in the sample is from the local supplier?part in the sample is from the local supplier?
Poisson Distribution (1/2)Let x is a no of occurrences of a randomLet x is a no. of occurrences of a random variable with a certain rate of occurrence (ג)
P.d.f!
)(x
exXPxλλ−
==
Where x = 0,1,2,……Binomial Can be approximated to Poisson if,
n is very large and p is close to zero, ג=np
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Poisson Distribution (2/2)If X is a Poisson random variable withIf X is a Poisson random variable with parameter (ג)
Thenλμ == )(
andxEλ
λσ == )(2 xVand
Example:
For the case of the thin copper wire, suppose that the number of flaws a Poisson distribution with a mean of 2.3 flaws per millimeter. Determine the probability of exactly 2 flaws in 1 millimeter wires.Determine the probability of 10 flaws in 5 millimeters of
iwire.
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Uniform DistributionSay x x2 x has equal probabilitySay, x1, x2, ….., xn has equal probability
P.d.f
Ex: R={0 1 2 3 4 5 6 7 8 9}
nxXP i /1)( ==R={0,1,2,3,4,5,6,7,8,9}f(x) = 0.1
E(x) = (a+b)/2V(x) = ((b-a+1)2 – 1)/12
Example:
Let the random variable X denote the number of the 48 voice lines that are in use at a particular time. Assume that X is a discrete uniform random variable with a range of 0 to 48. calculate the mean and the variance of X.
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Part Three
Continuous Random Variables and
Probability DistributionsProbability Distributions
Uniform DistributionA continuous random variable X with probabilityA continuous random variable X with probability density function. It uses to approximate several processes when could be boundaries and has equal chance.
xf =1)(
E(x) = (a+b)/2V(x) = (b-a)2 /12
abxf
−)(
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ExampleLet the continuous random variable X denoteLet the continuous random variable X denote the current measured in a thin copper wire in milliamperes. Assume that the range of X is [0,20 mA]. What is the probability that a measurement of current is between 5 and 10 milliamperes? Also, calculate the standard deviation of X.
Exponential DistributionA continuous random variable X for time betweenA continuous random variable X for time between events to happen.
xexf λλ −=)(
Where ג >0, and x>=0 E(x) = 1/ ג V(x) = 1/ ג 2
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ExampleIn a large corporate computer network, userIn a large corporate computer network, user log-ons to the system can be modeled as a Poisson process with a mean of 25 log-onsper hour. What is the probability that there are no log-ons in an interval of 6 minutes.
Normal Distribution (1/3)Any natural behavior with out any control fromAny natural behavior with out any control from human takes a normal distribution.
2
2
2)(
21)( σ
μ−−
=x
exf2πσ
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Normal Distribution (2/3)
( )σStandard Deviation
( )μMean
99.7 Percent
68 Percent
95 Percent
Y Y + sY - sY -2 s Y +2sY - 3s Y +3s
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Reliability
Monitoring a quality attributes over a specific
i d f tiperiod of time
System Reliability
System will perform at a specific level of a quality f ifi d l thfor a specified length.
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Why Monitoring Reliability?
B tt ll ti t fi b kd1. Better resource allocation to fix breakdowns.
2. Design an efficient preventive maintenance plan from failure analysis.
3. Monitor stocks and inventory levels (spare parts)parts).
4. Aggregate planning (Demand for full product + spare parts)
To Implement Reliability
C t l d i (M k ll1. Conceptual design (Make sure all components of systems will meet requirements)
2. Detailed/final design. Can you measure or predict reliability?predict reliability?
3. Planning for manufacturing.
4. Effects of operating & maintenance period.
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Cost of Reliability
F irs t Co s t (P ur cha se ) $
Tota l C o s t
Op tim um C os t
O per a ting & M ain ten ance C o st
R e lia bil ity
F a ilure r a te
Failure Analysis1. Failure rate, no. of components failing within
specified period.
2. Maintenance: Preventive maintenance (PM), Corrective maintenance (CM).
3. Catastrophic failure: wait till all component, or critical component failed.p
4. Availability: Probability that system is operable.
5. Mean time between failure (MTBF).
6. Mean time to fail (MTTF)
7. Mean time to repair (MTTR)T=0 T=t1
This is the first failure
MTTF
Failure (n) Failure (n+1)
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Hazard Function
)()()(
tRtft =λ
Where f(t) is a failure function, and R(t) is the reliability function
Hazard Rate (Bath tub Behavior)(t)ג
Region I Region II Region III
t1 t2t
Region I: Debugging region (warm up period)Region II: Operating regionRegion III: Burning out (wearing out)
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Types of Reliability Systems (1/3)(t)ג
t
Digital Systems: Short period of warm upLong period of OperatingShort period of burning out
Types of Reliability Systems (2/3)
t
(t)ג
Mechanical and Hydraulic System
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Types of Reliability Systems (3/3)
t
(t)ג
Administrative System (Governance Systems)In this system, No quality Management System
ExampleIf , The failure density function f(t) = 0.25 – (0.25/8)t, t>=0y ( ) ( )
Find all other reliability functions.
Solution:
1 Q( ) 0 25 (0 25/16) 21. Q(t) = 0.25t – (0.25/16)t2
2. R(t) = 1 – Q(t)
= (t)ג .3 f(t)/R(t)
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Mean Time To Failure (MTTF)∞
∫=0
)( dttRMTTF
Example:F(t)
0.25
If, f(t)=0.25-(0.25/8)t, find MTTF.
R(t) = 1- Q(t)t
8∫=8
0
)( dttRMTTF
Reliability & Maintenance
1. Applying corrective maintenance in region I
2. Applying preventive maintenance in region II (Increase period (t1 – t2), and reduce ג)
3. Applying both corrective & preventive maintenance in region III (reducing slope by using PM), In this region CM dominates PM.
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System Reliability
Any system with n components could be modeled
(flow charted) as:1. Series components
2. Parallel components
3. Hybrid components.
Series Components (1/2)
1 2A B1 2 n
In series system, any component fails, will cause a system failure
System reliability = System Success.
Rs = P(x1) * P(x2)……..* P(xn)
∏ ∏= =
==n
i
n
iiis RxpR
1 1
)(
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Series Components (2/2)Examples:Examples:1. Taking 3 courses in one area and each one depends
on the other (prerequisite).2. Car has six major subsystems, four of them are series.
I. Gas systemII. Engine systemIII. Transmission systemIII. Transmission systemIV. Axes
System Failure = Qs = 1 - Rs
∏=
−=n
iis RQ
1
1
Example:
A B1 2 3
For the previous system, if you know that,R1=0.9,
R2=0.8, and R3=0.7. Calculate RsRs=0.9 * 0.8 * 0.7 = 0.504
A B1 2 3
In a series system, Rs is getting smaller than the
components reliability Ri
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Series System Advantages
There are many highly reliable series systems in
use that offer a number of advantages:1. Use a minimum number of parts
2. Consumes minimum power
3. Takes up a minimum of space and adds a minimum weight.
Parallel Components1
In parallel system, all components fail, will cause a system failure
A B2
n
system failure
System reliability = 1- [System failure].
]1....[]1[]1[1 21 ns RRRR −×−×−−=
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Example:1
For the previous system, if you know that,R1=0.9,
R2=0.8, and R3=0.7. Calculate Rs
A B2
3
Rs=1- (1-0.9) * (1-0.8) * (1-0.7) = 0.994
In a parallel system, Rs is getting greater than the
components reliability Ri
Example:
L t h t f ll lLet each component for parallel
system has a reliability Ri = 0.7.
Find, reliability of system when
n=2, n=3, n=4, and n=5.0 920.940.960.98
11.02
R
Conclusion
The first redundant unit
will add to reliability
0.90.92
0 1 2 3 4 5
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Parallel System disadvantages
This can lead to significant increases in:1. Costs
2. Power consumption
3. Weight
4. Space requirements
Hybrid Components
A
1
3
4
2
B
5
5
5
R1 through R5 are the reliability values for subsystems 1 through 5:R1=0.98, R2=0.98, R3=0.92, R4=0.999, and R5=0.90Determine the Rsys.
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Stand-by-System
You need to switch to the redundant unit, when
the main component fails.
1. A is an operational unit
2. B is a stand by unit
A
By
3. Develop a switching concept and assume that it is reliable for smooth transition.
B
What is Maintenance?BS 3811:1974BS 3811:1974Maintenance is defined as: The work under takenin order to keep or restore a facility to anacceptable standard level.
Or
The combination of activities by which a facility iskept in, or restored to, a state in which it canperform its acceptable standard.
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Maintenance Policies
Maintenance Policies
“To Keep”Planned Maintenance
“To Restore”Unplanned Maintenance
- Time Based Maintenance- Condition Based Maintenance
- Corrective Maintenance- Run To Failure
- Risk Based Maintenance - Emergency Maintenance- Break down Maintenance
Preventive MaintenanceTime-based PMTime-based PM•Pure time )calendar) based: Weekly, monthly, annually, etc.•Used (running) time based: 1000 km, 1000 RH, 3000 RH, etc.Preventive maintenance actions usually include:
1. Cleaning 2. Lubricating
3. Changing filters
4. Replacing worn parts at prescribed times
5. Inspecting to find and eliminate potential failures.
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Predictive Maintenance(Condition based) Maintenance(Condition-based) Maintenance By monitoring key equipment parameters "Off-line or On-line“
Vibration analysisOil analysis Wear analysisWear analysisNoise analysisTemperature analysisPressure analysisQuality analysisEfficiency analysis, etc.
Corrective MaintenanceCorrective maintenance consists of all actions required toCorrective maintenance consists of all actions required to
retain a unit in its functional state after a failure occurs.
Preventive Maintenance actions usually include:
1. Preparation, obtaining the proper tools and test equipment, traveling,… etc.
2. Active maintenance, locating the cause of the failure, disassembling the unit, repairing the fault, reassembling the unit, checking out.
3. Delays, waiting for spares,… etc.
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Corrective versus preventive Maintenance
Preventive MaintenanceCorrective Maintenance Preventive MaintenanceCorrective Maintenance
MTBPMTTR, MTBF
Reduce the probability of failure
Affected by reliability, High reliability unit , Low frequently of CM
Increase Unit reliability
Done after unit fails
MaintainabilityIt measures a unit’s ability to be retained in, or restored to,It measures a unit s ability to be retained in, or restored to,
specific conditions. For maintainability calculations, the following
assumptions are made:
1. Maintenance is performed by qualified personnel.
2 Maintenance personnel have access to resource required2. Maintenance personnel have access to resource required for maintenance and repair.
3. Maintenance is performed according to prescribed procedures.
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AvailabilityIs the probability that a unit will be ready for use at a stated p y y
instant of time or over stated period of time, based on the
combined aspects of reliability and maintainability.
The reliability engineers must consider several elements in
addition to reliability and maintainability includingaddition to reliability and maintainability, including
1. System type.
2. Typical product use.
3. Downtime.MTTRMTBF
MTBFAvail+
=
According to Maintenance Information
(1)Complete
InformationPlanned PM
70 %
(2)Incomplete informationPlanned CM
20%
(3)Without
informationUnplanned CM( E )70 % 20% (or Emergency)
10%
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MMH Distribution in Industries
Maintenance Works
Planned
≥ 70 %
Unplanned
≤ 30 %
Minor repairs
≤ 20 %
Repairs
≤ 10 %
PM
≥ 45 %
Repairs
≥ 25 %
Maintenance Process (1/2)
Experience
Maintenance
InformationTools
Maintenance Planner
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Maintenance Process (2/2)
Tools:•Computer programs•International standards•Management tools, etc.
Information:•Catalog•Forms / reports•Data collection•PM levels•Job plans for each PM levelR
Experience:•Technical•Planning•Analysis •Decision making •Problem solving•Working conditions, t •Resources
•Cost rates•CM work orders•Failure analysis, etc.
etc.
Maintenance CostMaintenance costs are a major part of the total operating costs f ll f t i d ti l tof all manufacturing or production plants.Depending on the specific industry, maintenance costs can represent between 15% and 40% of the costs of goods
produced.For example in food related industries, the average maintenance cost represents about 15% of the cost of goods produced; while
in iron and steel, pulp and paper and other heavy industries , p p p p ymaintenance represents up to 40% of the total production costs.US industry spends more than $200 billion dollars each year on maintenance of plant equipment and facilities,
Maintenance Cost: 10 – 25 % & Spare parts Cost: 3 – 10 %
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Maintenance Cost Elements (1/2)
Di t tDirect cost:Spare parts & supplies costLabor costContract cost
Indirect cost:Overhead costOverhead costDown time cost
Maintenance cost = Direct cost + Overhead cost
Maintenance Cost Elements (2/2)
Cost to replace or repairCost to replace or repairLosses of outputDelayed shipmentScrap and rework
CostCost
PM CostPM Cost
Total Maintenance CostTotal Maintenance Cost
PM levelPM level
CM CostCM Cost
Best level Best level
Down Time CostDown Time Cost
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Maintenance Management (1/2)
MM is a powerful systematic methodology to maximize theMM is a powerful systematic methodology to maximize the facility performance and to improve the maintenance resource productivity, through optimizing the maintenance policies for the critical equipment.
MM - is the application of knowledge, tools and scientific techniques to identifying and analysis the maintenancetechniques to identifying and analysis the maintenance activities.
MM - decision-making process to select the best maintenance policies for improving the equipment reliability to an acceptable level.
Maintenance Management (2/2)
MM is the art of matching a maintenance's goals tasks andMM is the art of matching a maintenance s goals, tasks, and resources to accomplish a goal as needed.
MM is “do the right things, with the right tools, and in the right way".
Through:Define the target and constraints,I f ti ll ti & l iInformation collecting & analysis,Maintenance planning,Maintenance organization,Motivation & direction,Maintenance control,Corrective actions, and Learned lessons.
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Maintenance Management History
1st generation Higher plant availabilityLonger equipment life
2nd generation
Higher plant Availability &reliabilityGrater safetyBetter product qualityNo damage toenvironmentLonger equipment life
3rd generation
Fix it when itbroke
Longer equipment lifePreventive maintenance
Longer equipment life
2000 1990 1980 1970 1960 1950 1940
How do you measure MM Success?
Targets
CustomerSatisfaction
Cost & ResourcesTime
Satisfaction
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Maintenance SystemA system is a collection of components (or items)
- Technical Constraints
‐ Financial constraints
‐Facility / Plan
at acceptable standard‐ Target Maintenance
processes
A system is a collection of components (or items) that work together to achieve a certain objective.
‐ Reports‐ Information
‐ Resources
processes
Maintenance performance indicators
The output is equipment that is up, reliable, and well configured to achieve the planned operation of the plant.
Functional block diagram for a pump
Sub-system: Water Pump Unity p
Control system
Fluid type: Water
Flow rate: 35 m3/hourHead: 750 mPressure: 70 bar
Multi-stage centrifugal pump
Environment
El. Power: 132 kw380 V, 3 ph
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Main Components
Motor1800 rev/min
Pump35 ton/hr
60 bar
Coupling
1800 rev/min 60 barB1 B2
Main Components SpecsPump specifications:--
Motor specifications:--
Coupling specifications:--
Valves specifications:--
Bearing specifications:--
Strainer specifications:--
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Current PM ProgramItem Job plan Frequency
(1)Motor
(2)Coupling
(3)PumpPump
(4)Suction line
(5)Discharge line
(6)Valves
Root Cause Failure AnalysisItem Main Failures Root Cause MTBF
(1)Motor
(2)Coupling
(3)PPump
(4)Suction line
(5)Discharge line
(6)Valves
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As – is – Situation Policies for the main components
1) Motor
Failure PM PrD CM
2) Coupling3) Pump4) Suction Line5) Discharge Line6) Valves
Policy Freq. Policy Freq.
Developed PM PlanItem Job plan Frequency
(1)Motor
(2)Coupling
(3)Pump
(4)Suction line
(5)Discharge line
(6)Valves
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Modern MM SystemsThere are four modern approaches:There are four modern approaches:
•Optimal system maintenance (OSM),
•Risk Based Inspection (RBI)
•Reliability centered maintenance (RCM), and
•Total productive maintenance (TPM).
MM MethodologiesOSM RBI & RCM TPMOSM RBI & RCM TPM
Mainobjective
Improve equipment availability
Preserve system function & improve system availability
Improve overall system productivity
Approach Maintenance information analysis and
Improve the maintenance programSystem reliability
System overall analysisContinuous y
Using optimal mathematical modeling
y yanalysisFailure mode effect analysis FMEARisk analysis
improvement techniques
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Maintenance Policies (1/4)Maintenance Policies
(1)Failure-BasedReactive (ReM):- RTF- CM - BD:: (2)
Time-BasedPreventive (PM):- Calendar:
WeeklyMonthly
(3)Condition-BasedPredictive (PdM):- Oil analysis- Vibration analysis- Temperature analysis- Pressure analysis- Wear analysis- Efficiency analysis
(5)Total-BasedGlobal (GM):- OSM- TPM
::
(4)Risk-BasedProactive (PaM):
RCFAMonthly::
- Running:1000 R.H.1000 K.M.::
:: - RCFA- FMEA \ FMECA- HAZOP- RCM \ RCM2- RBI ::
Spectrum Analysis
0.30.60.91.21.51.8
1xRPM - BALANCE
2xRPM - ALIGNMENT
3-6xRPM - LOOSENESS
6-30xRPM 30-50xRPM
GEARS & ANTI FRICTION BEARINGS
1000 2000 3000 4000Frequency
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Vibration Spectrum and Parameter Bands
Ampl
itude
Sub-Harmonic 1X 2X Bearing Bearing Gears Bearing
1x 2x 50x
Trend ofBalance
Trend of Bearings
Alarm
1x 2x
5mm/sec
1mm/secTime
(Days)Time
(Days)
SELECTED FREQUENCY BAND ALARMING
Ampl
itude
Sub-Harmonic 1X 2X Bearing Bearing Gears Bearing
1x 2x 50x
Trend ofBalance
Trend of Bearings
Alarm
1x 2x
5mm/sec
1mm/secTime
(Days)Time
(Days)
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Maintenance Policies (2/4)Policy Approach GoalsPolicy Approach Goals
Reactive Run to failure (fix-it when broke).
Minimize maintenance costs for non-critical equipment.
Preventive Use-based maintenance program.
Minimize equipment breakdown.
PredictiveMaintenance decision based on equipment
Discover hidden failures and improve reliability for q p
condition.p y
critical equipment.
Proactive Detection of sources of failures.
Minimize the risk of failures for critical systems.
Global Integrated approach. Maximize the system productivity.
Maintenance Policies (3/4)Policy Approach Goalsy pp
RCFA Identification of root causes of failures. Eliminate failures.
FMECA Identification of criticality of failures.
Improve equipment availability.
HAZOPIdentification of hazards and problems associated with operations.
Improve HSE effect.
RCMDetermination of best maintenance requirements for critical systems.
Preserve system function & improve reliability.
RBIDetermination of an optimum inspection plan for critical systems.
Improve system HSE and availability.
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Maintenance Policies (4/4)
Policy Approach Goals
OSM
Optimization approach for the global maintenance system.
Maximize reliability measures and minimize maintenance cost rates.
TPMComprehensive productive-maintenance system.
Maximize plant effectiveness and resource productivity.
Maintenance Planning ConceptBefore you start to maintenance plan, consider...•Who is the ultimate customer?•Who is the ultimate customer?•What are the customer needs?•How long will the maintenance project last?•Where are we now?•Where should we end-up?•What are the cost constraints?•What are the technical challenges?So, Maintenance Planning must determines what, when, where, , g , , ,how, and by whom something is done.•What is to be maintained? "Description"•Why? "Target"•How? "Method"•By whom? "Resources"•When? "Schedule“•Where? "Location"
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Maintenance Planning Steps (1/2)Step Description
1. System criticality analysis HSE - Process – Down time – Cost – MTBF – MTTR - etc1. System criticality analysis HSE Process Down time Cost MTBF MTTR ... etc.
2. Equipment selection • Critical equipment • Non-critical equipment
3. Information collection & analysis
Maintenance catalog – Design information – Equipment history-Working conditions- PMs – CMs – Trouble shooting – Reliability information – HSE instructions. etc.
4. Target & constraints definitions
• Targets: Reliability, Availability, MTBF, MTTR, Down time, Cost, HSE level, .. etc.
• Constraints: Budget, Spare parts, Tools, Manpower,Information,etc.
5. Requirements & standard levels
• Functional levels: Flow rate, Head, Pressure, Power, .. etc.• HSE levels
6. Main failures determination Functional failures - HSE failures – Mechanical failures –Electrical failures - .. etc.
7. Root Cause Failure Analysis (RCFA)
Main failures, Root cause, RRC, Mechanism, Probability, MTBF, MTTR, Remedy.
8. Best maintenance policy • Run To Failure (RTF)• Time-based (Preventive) PM• Condition-based (Predictive) PdM• Risk-based (Proactive) PrM
Maintenance Planning Steps (2/2)Step Description
9. Maintenance policy planning Frequency- Levels- Alarm limits- Tools- Job plan- HSE plan- Spare parts-Duration- Manpower- .. etc.
10. Work orders • W/O # - W/O type- Dates/time - Responsibility- Level - Alarm limits-Tools- Job plan- HSE plan- Spare parts- Duration- Manpower- Failure -Root cause- .. etc.
• Complete Feedback.11. Measure Running hours- Noise- Vibration- Temperature- Oil level- viscosity- Flow
rate – Head – Speed - .. etc.12. Analysis Noise analysis- Vibration analysis – Temperature analysis - Oil analysis -
Flow rate analysis – Head analysis – Speed analysis - .. etc.
13 A ti G d diti13. Action - Good condition- Call for service (PM)- Call for repair (planned CM)- Breakdown (unplanned CM)
14. Performance evaluation & KPI
CM/PM- MTBF- MTTR- MTBM- MTTM- Reliability – Availability-Maintainability- RAM- Spare parts consumption rates- .. etc.
15. Improvement • Information – Maintenance levels- Tools – Spare parts – Manpower skills – Time – HSE - .. etc.
• Approach: FMEA - RCM - RBI- PMIS - .. etc.
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The Main Elements of Maintenance Plan
Equipment name & code,Eq ipment p io itEquipment priority,Maintenance start time,Maintenance down time,Maintenance level and type,Maintenance job description,Maintenance operations time,Maintenance effort (man-hour),Manpower requirements planningManpower requirements planning,Spare parts and supplies requirement planning,Tools requirements planning,Failure analysis,Maintenance cost estimation,Maintenance budget, and Safety instructions.
Maintenance Work Order•Work order number•Work order numberRequester Section:•Plant (or department) name / code, Equipment name / code•Equipment priority, Maintenance type & level (PM / Repair / Overhaul)•Job scope & description, ResponsibilityPlanning Section:•Manpower types & skills, Time estimation•Spare parts, Special tools•Expected equipment down time (from xxx to xxx), Cost estimation•Safety instructions, Responsibilityy , p yCraft Feedback:•Job scope & description, Manpower types & skills•Time estimation, Spare parts•Special tools, Actual equipment down time (from xxx to xxx)•Actual Cost, ResponsibilityCoding:•Plant (or department), Equipment•Resources (Manpower, Spare parts, Special tools)
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Maintenance ControlTotal Control Indicators:
1- Work quantity controlOver estimation, Under estimation
2- Time controlBehind schedule (late), Ahead schedule (early)
3- Cost controlCost overrun, Cost under-run
4- Quality controlA t bl l l N t bl l lAcceptable level, Non-acceptable level
5- Inventory controlOver estimation, Under estimation
6- Resources controlOver estimation, Under estimation
7- Plant condition control (HSE, etc.)Acceptable level, Non-acceptable level
Control Steps
1 Wh t t t l?1. What to control?2. What is the standard (target) performance?3. What is the actual performance level?4. Comparison between the actual & target.5. Detection of variance6 Identification of causes of variance6. Identification of causes of variance7. Corrective actions8. Learned lessons.
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Total Control Levels1 Review and data collection1- Review and data collection.2- Follow-up.3- Performance evaluation.4- Productivity analysis.5- Corrective actions.6- Learned lessons.6 Learned lessons.
System Effectivness
System Effectiveness
Efficiency Availability
R li bili M i i biliUtilization &
Resource productivity
Reliability
MTBF
MTBM
Maintainability
MTTR
MTTM
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Resources Productivity AnalysisProductivity Dimensions
CostQualityQuantityTime
Efficiency1- Technical Efficiency2- Operating Efficiency3- Production Efficiency4- Economical Efficiency
Effectiveness= Actual output /Planned output
Maintenance System Effectiveness:•It is related to performance•It is related to performance.•It is the degree of accomplishment of objectives.•How well a set of results is accomplished?
Maintenance System Efficiency:•It is related to resource utilization.•It is the degree resources utilization.• How well the resources are utilized to achieve the results.