1. Chapter 12 Maintainability and Availability

2. 12.1 introduction Availability analysis of the system requires a knowledge: (1)How the components are functional connected. (2)The failure process of the component. (3)The method of operation and the definition of the failure. (4)The repair or maintenance police.

3. 12.2 Maintainability 12.2.1 Concept Maintainability M(t) : the probability of repairing a failed component or system in a specified period of time. Two kinds: Preventive maintainability Corrective maintainability

4. 12.2.2 Preventive maintainability reliability of the system

5. System Reliability

10. Example 12.2 derive the condition under preventive maintenance is beneficial to the

13. 12.2.3 imperfect maintenance

16. 12.2.4 Repair time distribution

22. 12.2.5 Unrepaired failure Number of unrepaired failure in time

23. 12.2.6 Optimum replacement strategy The total number of the times the component is replaced is given by

25. 12.2.7 Spare parts requirement The probability of having n failure in time t :

26. 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

27. 12.3 Availability 12.3.1 definition

29. 3. Steady state availability 4. Inherent availability 5.Achieved availability 6.Operational availability

30. 12.3.2 Availability Analysis 12.3.3 Development of model

34. 12.3.4 system with single component

39. 12.3.5 Series system One repair person :

43. Two repairperson

44. 12.3.6 Parallel system

45. One repair person

46. Two repair persons

47. 12.4 Optimization Approach