Based on a simulation of aircraft operations according to realistic flight schedules, part removals according to their specific reliability characteristics as well as delivery and re-balancing logistics, the Component Demand Forecaster (CDF) provides the User a view of how the inventory network and the expected Service Level performance is expected to evolve over time. Input from the Field Parameter Analyser is used in conjunction with planned events including flight network, maintenance plans, fleet changes, and modification plans. A rolling inventory profile is produced for the User to determine potential overstock and understock situations within the forecasting horizon and give an indication of the impact. The CDF module takes into account all types of removals that are expected or likely to take place, i.e. unscheduled demand, scheduled demand and hard-time removals, and calculates the forecasted inventory profile based on the demands and the repair/reorder cycle.