가변 생산속도 및 판매상실을 갖는 생산-재고 모형의 분석

Abstract

In the thesis, the lostsales production-inventory model with service time and variable production speed is analyzed. Customers arrive in the system according to the Poisson process. The service times of customers are independent and identical distributed exponential random variables. At a service completion epoch, the customer leaves the system with an inventory item. The server can provide the service only when the inventory level is positive. If the inventory level drops to zero, the customers in the system wait for the service until inventory is replenished. During the stockout period, the newly arriving customers are assumed to be lost. The inventory items are replenished by internal production based on (s,S)-policy, and the production times are assumed to be exponential. The production rate is assumed to be variant. We derive the stationary joint probability of the inventory level and the number of customers in product form. Using the joint probability, we determine the optimal operational strategy that minimizes the cost per unit time.