Some comments on normal approximation for stochastic demand processes

In multistage production systems under uncertainty as well as in local decentralized stochastic inventory control systems, there are often easily described external demand processes and a very complex internal demand depending on the structure of the system, the control policy, and the external demand. This paper discusses a functional normal approximation for an internal demand process by a Wiener process with drift. It applies the present approach to Sherbrooke’s two-echelon model.