Effectiveness Comparisons 



A model based on mission-oriented factors is a reasonable method 

 for assessing system effectiveness. This approach is utilized in this study, 

 although some important questions must be answered concerning the 

 possibilities of constructing the more unconventional systems. A modified 

 version of the model proposed by the Weapon System Effectiveness Industry 

 Advisory Committee (WSEIAC) is discussed. The following definitions 

 apply: 



System effectiveness is a measure of the degree to which a system 

 may be expected to fulfill a specific set of mission requirements. It 

 is a function of availability, dependability, capability, and the 

 relationships between these factors. Availability is a measure of the 

 state of a system at the beginning of a mission. Dependability is the 

 probability of a system being in a certain state during a mission, 

 given the state of the system at the beginning of the mission. 

 Capability is the ability of the system to fulfill mission objectives, 

 given the system condition during the mission. 



The framework for system effectiveness evaluation is based on avail- 

 ability, dependability, and capability. Analytical methods based on the 

 relationships among these factors enabled the authors to arrive at a numerical 

 estimate of system effectiveness. 



In general terms, the heavy-lift system must be capable of meeting 

 m operational requirements while operating in n probable states. (The values 

 of the numbers m and n are determined later.) The effectiveness of a system 

 is composed of m figures of merit e| e|^ and e^^ 



where 



Z 2 'i "^ij ^jk'" ^ = '■' 



32 



