A note on a lot sizing heuristic for deteriorating items with time-varying demands and shortages

In the present article, an existing heuristic procedure is applied to an inventory of deteriorating items with (i) linearly and (ii) exponentially time-varying demands and shortages over a fixed planning horizon. In a similar problem, Hariga and Al-Alyan [Hariga RI, Al-Alyan A. A lot sizing heuristic for deteriorating items with shortages in growing and declining markets. Computers & Operations Research 1997;24:1075-83] allowed shortages in all cycles except in the last one (policy-B). Here shortages are considered in each cycle and are completely backlogged (policy-A). The successive scheduling periods over an infinite time horizon are adjusted for a finite planning horizon following different adjustment policies (APs) that are proposed in an algorithmic form. Numerical examples are taken from Hariga and Al-Alyan [20] to show that the replenishment policy-A results in a lower average system cost than that of policy-B in both types of demand patterns. It is also found that the approximate results under the policy-A are closely associated with those of the optimal ones.