The Dyna-METRIC model was developed to study and predict the readiness of groups of aircraft squadrons as determined by a major subset of logistics resources, namely, those associated with component repair and resupply. This report describes the mathematical approaches to modeling the effects of spare parts supply, component repair, and related processes on combat capability. It does not describe the implementation of any specific version of Dyna-METRIC. Section II reviews the time-dependent pipeline equations. Section III describes time-dependent stockage and component-repair measures of performance. Section IV combines these measures to give aircraft capability measures. Section V introduces the pipeline model for indentured components, while Sec. VI describes the pipeline equations for the time-dependent, multiple-echelon model. Section VII describes the optimization techniques for supply requirements, and Sec. VIII describes the approach for limited service facilities.