Control strategies for inventory management.

This paper describes a control systems approach to the management of inventory. Normal inventory operation is an example of proportional control. Several control algorithms including Pseudo-Derivative Feedback (PDF), Proportional, Integral and Derivative (PID) and Feedforward control are used in this paper to produce a more sophisticated form of inventory operation that can easily reduce stock levels by up to 80% compared to 20-30% with MRP and hence reduce cost. Settling times are reduced by a factor of 50%. Modelling was achieved using the Simulink simulation package using equations developed by Ferris and Towill for a single level industrial system model rather than a conventional System Dynamics computer package. The best controller is shown to be a PID controller with Feedforward. This controller did not cause any significant oscillatory inventory level changes. These techniques compare well with other investigators using control strategies. This has special significance for JIT and MRP methods