Patent Document ID: 6021396
Application ID: 08974286
Patent Flag: 1

Claim One:
1. A computer implemented method for generating sensitivity information for an (R,s,S) policy inventory control system with back-ordered demand, where s is a specified reorder point and S is a specified order up to level value such that when an inventory position is below s at the start of a time period an order is placed to bring the inventory position up to S, said method comprising the steps of: reading input data from databases on inventory and simulation parameters and initializing variables, said parameters including a perturbation value .DELTA.; for a time horizon under consideration, performing an inventory simulation with perturbation analysis, the perturbation analysis including a tracking of a plurality of paths of events representing an inventory state of a nominal system based on s and S, and an inventory state of one perturbed system based on q perturbed by the value .DELTA. where q=(S-s), using a combination of an adjusted Infinitesimal Perturbation Analysis (IPA) algorithm and a set of finite difference calculations; based on the perturbation analysis for the time horizon under consideration, calculating sensitivity information on average inventory and back orders with respect to changes of .DELTA. in s and S values; computing an average change over all replications of the step of calculating; and updating average statistics and outputting sensitivity information on performance measures.