Du Dingzhu;F.K.Hwang
Journal of Systems Science and Complexity. 1990, 1(1): 36-045.
Consider a system containing a type of n devices. Each device consists of mparts. Given mn parts for n devices with different working probabilities, how do we groupthem into n devices such that the system is most reliable. A monotonic grouping means that the best parts are put together, then the best remaining parts are put together, etc. A sufficient and necessary condition for such grouping being optimal will be given in this paper. As an application, we show that the monotonic grouping is optimal for the two-stagek-out-of-n system. When m=2, we also study the grouping that the best pairs to the worst, the second best pairs to the second worst, etc., associated with a redundant device problem.