Abstract: To research and establish the general evaluation model of Reliability,Maintainability and Supportability (RMS) factors for the weapon system in condition of consideration operation is valuable for the simplified analysis and reduced application of simulation technique in the course of RMS requirement determination. Upon the base of analyzing the usage of early warning airplane in operational environment, its mathematical mission effectiveness model for operational condition is established in term of probability principles. This work provides the facility and model for determinating the RMS indexes of early warning airplane by using analysis method, and gives a theoretical basis for the quantitative evaluation of RMS factors’ effect on the operation of early warning airplane.

Key words: mission effectiveness, system effectiveness, mission effectiveness model, early warning airplane, RMS indexes determination