17 USC 105 interim-entered record; under review.In an effort to meet the challenges presented by the fiscal realities of today's defense budget, the Department of Defense (DoD) is seeking to exploit technology that promises to decrease operating costs, while improving operational readiness. Efforts which reduce repair costs, system down time, and the reliance upon outside technical representative are of particular interest. The development of the MK92 Maintenance Advisor Expert System (MK92 MAES) is one such effort. This paper describes the design and development of the MK92 MAES for the diagnosis and repair of the MK92 MOD 2 fire control system deployed on U.S. Navy guided missile frigates. System development is presented in terms of an expert system life cycle model which includes a thorough cost/benefit analysis, a novel approach for knowledge acquisition, an implementation strategy using a visual expert system development environment, and a phased deployment strategy. The system was developed by faculty and graduate students at the Naval Postgraduate School in cooperation with the Naval Warfare Center, Port Hueneme Division.The author thanks...Dean of Research Office at the Naval Postgraduate School for paying the publication cost