Given a system in state j, the probability of the system satisfying the 

 k^'' figure of merit in some predefined manner must be determined. The 

 determination of these elements requires judicious selection of only the 

 critical factors which can perhaps be arrived at only by making realistic 

 assumptions relating to the accountable factors. 



The general model discussed above can be applied to the effectiveness 

 evaluation of any system. In highly complex systems, it may be necessary to 

 generate the availability, dependability, and capability matrices with a digital 

 or analog computer. Simulation techniques are also available for use in 

 many system evaluations. 



Heavy-Lift Analysis 



The value of an analytical approach is that it requires the design team 

 to analyze the impact of and relationships between design parameters, in 

 the case of the heavy-lift system, the prediction of system effectiveness is 

 made difficult by the lack of adequate data. The absence of comprehensive 

 data sources, particularly data of an experimental nature, is currently the 

 weakest step in the entire process. As a consequence, the model just 

 discussed is necessarily subject to simplification and assumption. Nevertheless, 

 the principles and relationships of the model can be used at some future date 

 to analyze new data as it accumulates. At present, there is no choice but that 

 of simplification. 



Availability. Two possible system states are assumed in this study: 



State 1 : operative 



State 2: inoperative 



Therefore 



A = [ai 82] 



where a-] = probability the system is operative at the beginning of a mission 



82 = probability the system is inoperative at the beginning of a 

 mission 



35 



