This report summarizes the results of a short-term project aimed at demonstrating the applicability of the DITOPS scheduling system  to the air medical evacuation (MEDEVAC) re-planning problem faced by USTRANSCOM. DITOPS is an advanced prototype system developed at Carnegie Mellon University for development, analysis and revision of large-scale transportation schedules, and applied originally to the logistics domain of strategic deployment. DITOPS builds directly on concepts first demonstrated in the OPIS scheduling system and emphasizes a reactive, constraint-based approach to scheduling. It provides both specific techniques and a system architecture for efficient, localized revision of plans/schedules in response to changed constraints or decisions. Typical of most practical planning and scheduling domains, such reactive planning capabilities are recognized as central to effective MEDEVAC decision-making.
Our specific goal has been to use DITOPS to construct an evaluation prototype for reactive planning in the medical evacuation domain, to provide a benchmark for and a point of comparison with the Carnegie Group's TRACES reactive planner component. From a system development perspective, DITOPS can be seen as a toolkit and a class library for configuring different planning and scheduling application systems . We first outline the basic methodology for application development taken in DITOPS and summarize the system's core components for constructing domain models. In subsequent chapters we describe the extensions and customizations developed to implement the current medical evacuation planning prototype. The extent of the current prototype's capabilities - which have been achieved in a very short period of time - clearly demonstrates the potential of the approach.