Using imperfect advance demand information in lost-sales inventory systems with the option of returning inventory

Motivated by real-life applications, we consider an inventory system where it is possible to collect information about the quantity and timing of future demand in advance. However, this Advance Demand Information (ADI) is imperfect as (i) it may turn out to be false; (ii) a time interval is provided for the demand occurrences rather than its exact time; and (iii) there are still customer demand occurrences for which ADI cannot be provided. To make best use of imperfect information and integrate it with inventory supply decisions, we allow for returning excess stock built up due to imperfections to the upstream supplier and we propose a lost-sales inventory model with a general representation of imperfect ADI. A partial characterization of the optimal ordering and return policy is provided. Through an extensive numerical study, we investigate the value of ADI and factors that affect that value. We show that using imperfect ADI can yield substantial savings, the amount of savings being sensitive to the quality of information; the benefit of the ADI increases considerably if the excess stock can be returned. We apply our model to a spare parts case. The value of imperfect ADI turns out to be significant.