Effect of Demand Distributions and Declining Urgency of a Perishable Item in Relief Ordering Policy

Abstract

Urgency and perishability are highlighted during relief operation after the 2011 great east Japan earthquake. Perish rate is influenced by several reasons including poor preserving facilities. This paper presents a dynamic programming model to optimize decisions (i.e., “how much and when to order”) for replenishing a perishable item facing declining demand and urgency. An exponential distribution of declining demand is adopted. The results of the model for exponential distribution demand is compared with that for linear declining demand. The proposed model exhibits a variation in replenishment intervals and order quantity. Herewith, total cost of inventory changes for urgency and perishability. In addition, the trend of delayed satisfied demand in planning horizon have patterns that do not depend on parameter values rather depends on declining demand distribution type.