2-2] FORMULATING THE SYSTEM STUDY PLAN 49 



"What does the weapons system require of the airborne radars (AI and 

 AEW) to achieve a satisfactory level of mission accomplishment?"^ 



The basic elements of this problem are shown in Fig. 2-2. The operational 

 requirement defines a weapons system problem. By the processes described 

 in Paragraph 1-8, the operational requirement leads to the establishment 

 of the concept of a system which depends for its operation upon the charac- 

 teristics of a number of subsystems — aircraft, missiles, detection devices, 

 and shipboard installations, for example. 



As is apparent from this figure, the solution to the radar requirements 

 problems will involve consideration of many complex characteristics and 

 relationships external to the airborne radars. Hence, the middle two 

 questions (Fig. 2-1) and their answers are fundamental to further progress. 

 For the hypothetical problem, the known and unknown elements of the 

 problem are displayed in Figs. 2-2 through 2-8. These will be discussed in 

 greater detail in subsequent paragraphs. 



The plan for action will develop quite naturally from the indicated 

 sequence of questions and answers. Elements of the problem that are not 

 known or understood must be investigated in greater detail and related to 

 the known elements. In some cases, adequate information may not be 

 available on the unknown elements of the problem — or the path to under- 

 standing may be blocked by the inherent difficulty of the problem. These 

 cases will require that arbitrary assumptions be made in order that the 

 analysis can proceed. 



When a sufficient understanding of the overall problem is obtained by 

 analysis (or assumption), weapons system models are constructed. These 

 models have as variable parameters the performance characteristics of the 

 airborne radar known to be important to weapons system operation. 



Using the techniques of Operations Research and Systems Analysis, these 

 models are "played" against the target inputs (Fig. 2-2). The level of 

 system performance (Mission Accomplishment) obtained is compared with 

 the operational requirement, thereby generating a measure of the system 

 capabilities (or deficiencies). By such processes, mission accomplishment 

 may be related to the radars' performance characteristics (see inset, Fig. 

 2-2) thereby providing a means for obtaining the true requirements of the 

 airborne radars as dictated by the weapons system requirements. 



It is important to emphasize once again that the derivation of require- 

 ments should not be aflFected by state-of-the-art considerations in radar 

 technology. The purpose of the analysis is to define the radar problem, not 

 to solve it. Only after this task is completed is the radar designer free to 

 turn his attention to the job of designing and building a specific radar 

 system to meet the requirements imposed by the weapons system problem. 



iThe problem of defending a carrier task, force is quite analogous to the defense of a city 

 or important military base. 



