The block replacement problem

The block replacement policy requires that a unit or a block of units be replaced at specified timesk T, k = 1, 2,… and at failure. The mathematical solution to the problem of what is the optimal time Tfor replacement is well known and this paper describes this solution for the special cases of a truncated normal, gamma or Weibull life distribution. Graphs and tables are presented from which one can readily ascertain the optimal solution for these models.