A Continuous Review Inventory System with Retrial Customers and Two-Stage Service

In this paper, we developed a model of a retrial inventory sys tem in which there exists two-stage service. The demanded item is delivered to the customer after a random time of servi c . The interarrival times of customers, lead times, the ret rial times and service times are assumed to have independent exponential d is ribution. The joint probability distribution of the num ber of customers in the system and the inventory level is obtained in the steady s tate case. Some important system performance measures and t he long run total expected cost rate are calculated. We numerically dem onstrate the model and investigate the impact of different m odel-parameters on the optimal decisions.