THE SYSTEMS APPROACH TO AIRBORNE RADAR DESIGN 



31 



initiation of an operational requirement to the fabrication of service 

 equipment designed to fulfill the requirement. On the right of the figure 

 are the definitive outputs or accomplishments resulting from this develop- 

 ment. In the middle of the figure are the evaluation processes which meas- 

 ure the level of accomplishment attained in the problem-solving phases 

 of the development. The outputs of these evaluations may also be used 

 to modify succeeding phases of the development process. 



The diagram also indicates feedbacks from the various development 

 phases into preceding phases. These reflect the fact that as more is learned 

 about the system, prior concepts must be modified and expanded to ensure 

 that the system development objectives are current and realistic. 



Viewed in its entirety, the indicated procedure provides a basis for 

 playing current accomplishment against the requirement to obtain a 

 continuous rating factor representing the generated system capability. 



The step-by-step processes for executing the system development plan 

 may be summarized as follows. 



Operational Requirement. The overall system objective is set forth 

 in an operational requirement . This requirement usually outlines the 

 military task(s) which the weapons system must perform. It will also 

 specify — or at least indicate — the level of fnission accomplishment which 

 the system must achieve to accomplish the desired military objective. 

 The mission accomplishment requirement often has the general form dis- 

 played in Fig. 1-25. The weapons system must be operative in a given time 



a TIME (YEARS) b 



Fig. 1-25 Operational Requirement. 



period a-l?. The desired level of mission accomplishment represents the 

 best estimate of what the military planners believe is necessary to achieve 

 unquestioned military superiority in a given area of interest. This goal 

 may be variable over the expected operational use cycle (as shown) by 

 reason of anticipated introduction of new techniques by the enemy. 



The minimum acceptable level of mission accomplishment represents a 

 capability which the military planners believe is still useful enough to 



