In this paper we investigate the convexity of the annual total cost function for the Hadley & Whitin (1963) continuous review (Q,R) inventory model with backorders and fixed lead-time, when the reorder point is non-negative and the cost per unit backordered is used to calculate the expected...

Logistics is one of the most important compenents in achieving the success for the firms in competition in the present day and that the employment of the qualified people who graduated from universities by firms in this field is crucial. For this reason, that the promising logistics managers...