The Application of Queueing Theory to Continuous Perishable Inventory Systems

Abstract

This paper develops two distinct models for studying inventory systems with continuous production and perishable items. The perishable items have a deterministic usable life after which they must be outdated. For each of the models, analytical expressions derived from queueing theory, are found for the steady-state distribution of system inventory. Knowledge of this steady-state behavior may be used for evaluation of system performance, and for consideration of alternatives for improving system performance. Both models assume that inventory is replenished by a continuous production process. The first model, assuming continuous inventory units, has Poisson demand requests with the size of each request distributed as an exponential random variable. The second model has Poisson demand requests with all demands being for a single unit. The analysis for both models exploits the similarity of the inventory system with a single-server queueing system.