GIPSI is one of several interactive computer packages currently being used within the University of Aston Management Centre both as a teaching aid and as a research tool within the area of Production and Operations Management. GIPSI allows users to simulate four principal, single product inventory policies and provides a variety of options for the introduction of demand and leadtime data. The package can accept product cost data and also related inventory operating costs. Users can either specify control parameters, or optimum values can be sought using a simplex procedure. Information produced by the package covers such measures as: average stock levels, stockout frequency and durations, net revenue (with and without inflation) and also service levels.