Post on 16-Nov-2015
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Chapter 12Maintainability and Availability
12.1 introductionAvailability analysis of the system requires a knowledge:How the components are functional connected.The failure process of the component.The method of operation and the definition of the failure.The repair or maintenance police.
12.2 Maintainability12.2.1 ConceptMaintainability M(t) : the probability of repairing a failed component or system in a specified period of time.Two kinds:Preventive maintainabilityCorrective maintainability
12.2.2 Preventive maintainabilityreliability of the system
System Reliability
Example 12.2 derive the condition under preventive maintenance is beneficial to the
12.2.3 imperfect maintenance
12.2.4 Repair time distribution
12.2.5 Unrepaired failure
Number of unrepaired failure in time
12.2.6 Optimum replacement strategyThe total number of the times the component is replaced is given by
12.2.7 Spare parts requirementThe probability of having n failure in time t :
Example 12.9 Three kind of component in an system : 20 in type A (failure rate 0.002), 130 in type B (failure rate 0.0001), and 100 in type C (failure rate 0.0005). Find the number of spare parts required to cover the mission period 30 days and 99 percent of probability
12.3 Availability12.3.1 definition
3. Steady state availability
4. Inherent availability
Achieved availability
Operational availability
12.3.2 Availability Analysis
12.3.3 Development of model
12.3.4 system with single component
12.3.5 Series system
One repair person :
Two repairperson
12.3.6 Parallel system
One repair person
Two repair persons
12.4 Optimization Approach