The Single Army Battlefield Requirements Evaluator (SABRE) is a decision aid that combines rule-driven scoring strategies and domain-specific heuristics to solve a constraint satisfaction problem. The main SABRE algorithm performs a function called "sourcing," which refers to the allocation of resources to satisfy a set of requirements that may or may not be feasible in terms of the resources available. In the context of this application, the resources are military organizations, and the requirements refer to the needs of a commander-in-chief who is responsible for conducting a military operation. SABRE is presently used in both an operational and an analytical role. The primary operational user is an Army command that is responsible for choosing specific Army units for overseas deployment during a national emergency. Before SABRE, this function was performed manually, involved nineteen or more people and could take up to nine days, depending on the number of requirements. Using SABRE under ideal conditions, a single person can perform the function in a couple of hours. However, SABRE is designed to be a partner in the sourcing process. There are times when the sourcing solution involves highly subjective trade-offs that require human involvement. Therefore, the organization that is using SABRE has instituted procedures that permit human expert involvement when required; otherwise, a single "SABRE operator" can perform most resource allocation tasks.