1-10] 



WEAPONS SYSTEM MODELS 



Radar Range 



37 



Target Inputs 



TTT 



Fixed Elements 



Mission Accomplishment 



RADAR DETECTION RANGE 



Fig. 1-27 Diagrammatic Representation of a Model Used to Determine Sensitivity 

 of Mission Accomplishment to Variations in Radar Detection Range. 



the elements of the system model interact to provide a generated mission 

 accomplishment as shown in Fig. 1-27. From such a model, the effect of 

 radar range upon system effectiveness could be obtained for various inputs 

 (targets), yielding the characteristic type curves shown. 



It is far more convenient to conduct an experiment with a model of a 

 system than with the system itself. This is particularly true with a military 

 weapons system where the testing of actual hardware is enormously 

 expensive. Moreover, system hardware usually is not available until 

 long after the original concepts. Theoretical models are required to predict 

 expected system performance. 



There are three classes of models which can be used in systems analysis 

 work: iconic, analogue, and symbolic. Briefly, we may define the character- 

 istics of these model types in the following ways: 



1. An iconic model represents certain characteristics of a system by 

 visual or pictorial means. 



2. An analogue model replaces certain characteristics of the system 

 it represents by analogous characteristics. 



3. A symbolic model represents certain characteristics of a system 

 by mathematical or logical expressions. 



