Đang chuẩn bị nút TẢI XUỐNG, xin hãy chờ
Tải xuống
RELIABILITY OPTIMIZATION The preceding chapters of this book discussed a wide range of different techniques for enhancing system or device fault tolerance. In some applications, only one of these techniques is practical, and there is little choice among the methods. However, in a fair number of applications, two or more techniques are feasible, and the question arises regarding which technique is the most cost-effective. To address this problem, if one is given two alternatives, one can always use one technique for design A and use the other technique for design B | Reliability of Computer Systems and Networks Fault Tolerance Analysis and Design Martin L. Shooman Copyright 2002 John Wiley Sons Inc. ISBNs 0-471-29342-3 Hardback 0-471-22460-X Electronic 7 RELIABILITY OPTIMIZATION 7.1 INTRODUCTION The preceding chapters of this book discussed a wide range of different techniques for enhancing system or device fault tolerance. In some applications only one of these techniques is practical and there is little choice among the methods. However in a fair number of applications two or more techniques are feasible and the question arises regarding which technique is the most cost-effective. To address this problem if one is given two alternatives one can always use one technique for design A and use the other technique for design B. One can then analyze both designs A and B to study the trade-offs. In the case of a standby or repairable system if redundancy is employed at a component level there are many choices based on the number of spares and which component will be spared. At the top level many systems appear as a series string of elements and the question arises of how we are to distribute the redundancy in a cost-effective manner among the series string. Specifically we assume that the number of redundant elements that can be added is limited by cost weight volume or some similar constraint. The object is to determine the set of redundant components that still meets the constraint and raises the reliability by the largest amount. Some authors refer to this as redundancy optimization Barlow 1965 . Two practical works Fragola 1973 and Mancino 1986 are given in the references that illustrate the design of a system with a high degree of parallel components. The reader should consult these papers after studying the material in this chapter. In some ways this chapter can be considered an extension of the material in Chapter 4. However in this chapter we discuss the optimization approach 331 332 RELIABILITY OPTIMIZATION where rather .
