The Force Requirements Expert System (FRESH) is a force employment and resource allocation decision aiding tool which supports the Commander in Chief of the US Pacific Fleet (CINCPACFLT). FRESH is an embedded knowledge based system, integrated with conventional components of the Naval Command and Control System in the CINCPACFLT Command Center. FRESH’s development included innovations in knowledge engineering, system engineering, and manmachine interfaces. FRESH has resulted in demonstrated improvements to both accuracy and timeliness of decision making. FRESH has been deployed for two years. Development began in 1985; its cost was about $10M. The key to the successful introduction of knowledge based systems technology into the operational Navy environment has been the establishment and use of a testbed development and evaluation facility in the operational environment itself.