N Kaufman; TRW SPACE TECHNOLOGY LABS REDONDO BEACH CALIF.
This report presents a model of a system subject to a mixed maintanance policy and derives equa tions which can be used to produce a numerical value for the availability of such a system. An example of a system subject to such a mixed main tenance policy is the Inertial Guidance System of the Atlas Weapon, which is monitored continuously at a given test level and checked out periodical ly at a higher test level. In addition, a dis cussion of the data requirements necessary to estimate the parameters of the model is presented. (Author).