In this paper we investigate the minimization process of the exact cost function for a continuous review (Q,R) inventory model with non-negative reorder point and fixed lead-time. Backorders are allowed and the unit shortage cost is used to determine the expected annual shortage cost. Provided that the lead-time demand has J-shaped or unimodal distribution satisfying specific assumptions we derive the general condition when the minimum cost is attained at a positive reorder point or at a reorder point equal to zero. Based on this condition a general algorithm is developed.
