Time Series Models for Predicting Monthly Losses of Air Force Enlisted Personnel

The Short-Term Aggregate Inventory Projection Model (SAM) is the component of the Enlisted Force Management System that makes monthly projections (for the rest of the current fiscal year) of the aggregate force (the total enlisted force across all specialties). Module 1 (the separation projection module) of SAM is designed to forecast the monthly loss and reenlistment flows that would occur in the absence of early release and early reenlistment programs. This Note describes time series models that predict monthly losses and reenlistment using an assortment of modeling approaches. These include constant rate, regression, autoregressive, and straight-line running-average models. For each model, the Note explains why a certain approach was chosen, shows how the model was fit, and presents the resulting model.