chapter  20
14 Pages

Inventory Control Models

Customers arrive at a discount store every Exponential (2) minutes. €e store has three clerks who receive a batch of customer orders and then proceed to an adjacent warehouse to ›ll them. Customers are served as they arrive. However, when the customer queue builds up, a clerk can service a maximum of six customer orders in any one trip. Travel time to and from the warehouse is UniformContinuous (0.5, 1.5) minutes each way. Once in the warehouse, the processing time depends on the number of customers being served. It is estimated that the acquisition time is Normal (μ, σ2), where the mean μ equals the number of customers times three minutes per customer, and the standard deviation σ is estimated as 0.2 * μ. Upon return from the warehouse, the clerk delivers orders to respective customers in the same sequence in which the orders were received. €e time for each customer to receive an order is UniformContinuous (1, 3) minutes. After all waiting customers have received their order, the clerk begins another trip to the warehouse.