A single server perishable inventory system with N additional options for service

This article presents a perishable (s; S) inventory system under continuous review at a service facility in which a waiting hall for customers is of nite size M. The arrival instants of customers to the service station constitutes a Poisson process. The life time of each items is assumed to be exponential. All arriving customers demand the rst \essential" service, whereas only some of them demand the second \optional" service, and the second service is multi-optional. The joint probability distribution of the number of customers in the waiting hall and the inventory level is obtained for the steady state case. Some important system performance measures in the steady state are derived, and the long-run total expected cost rate is also calculated. We have derived the Laplace-Stieljes transforms of waiting time distribution of customers in the waiting hall. The results are illus- trated numerically.