Optimal Issuing Policies

Consider a stockpile consisting of n items where the ith item has a rating r_i, i = 1, ..., n. An item with rating r, if kept in stockpile until time t and then released to the field, will have a field life of rd(t). Thus it is assumed that for any t, the field life for issuance at time t is proportional to the time 0 field life. Items are to be issued one by one from the stockpile to the field until the stockpile is depleted. The ith issued item is placed in the field immediately upon the death in the field of the (i - 1)st issued item. Conditions for LIFO and FIFO optimality are obtained.