  In a dependent multi-component system, increasing the deterioration of a part
leads to the increased deterioration rate of other parts as well. In these
systems, a deterioration limit is usually pre-determined for each part and the
considered part is replaced while reaching this limit. In this paper,
replacement conditions of these parts were examined according to the
replacement times in the past. Using dynamic programming, for every
deterioration rate of part 1, there is a deterioration limit for part 2, after
which either part 2 or both parts should be replaced. The only available system
data are the replacement time of the parts in the past according to the
replacement policy at the time of reaching deterioration limit. Therefore,
simulated annealing optimization method was used for estimating deterioration
rates. Finally, two examples were presented for comparing the proposed method
with the special limit replacement method, which showed the significance
superiority of the former.
