Recent initiatives associated with the military force drawdown and declining Department of Defense budget mandate reducing military investment in spare parts inventories while maintaining force readiness. It is therefore important in the present environment to improve demand forecasting accuracy in order to meet supply performance goals. This thesis examines a naval aviation intermediate level inventory, the Shorebased Consolidated Allowance List, Yokosuka, Japan. The primary focus is to develop an alternate demand forecasting model for the Yokosuka SHORCAL. The present forecasting model averages demand for an item over a twelve month period to determine its forecast. The alternate model consists of two sections. The first section is a causal model for forecasting demand originating from aircraft carriers. Flying hours and carrier deployment are used as independent variables. The second section uses a time-series and a marginal value method to forecast causal residuals and non-carrier demand. The two sections are then combined into a final forecast for an item. Demand history for seven Aviation Depot Level. Repairables is used to develop the mode. The alternate model demonstrates improved forecast accuracy, measured as reduced forecast error, when compared to the present model.