1-12] CONSTRUCTION AND MANIPULATION OF MODELS 43 



each characterized by a time delay response characteristic — is basic to 

 our modeling approach. 



Bearing these observations in mind, we may outline the structural 

 composition of a weapons system model as follows: 



1. Input Variables — The input variables include all the characteristics 

 of the enemy target complex — size, number, location, speed, defense 

 capability, etc. — that are pertinent to the operation of the weapons 

 system. Also included are the elements of the fixed environment — the 

 physical environment, the environment provided by other weapons sys- 

 tems, etc. — that affect the operation of the weapons system. 



2. Mission Accomplishment Goals — This is a quantitative expression 

 of the desired system output. Usually, it derives from the operational 

 requirement. This quantity and the input variables define the problem 

 that the weapons system must solve. 



3. System Logic — The system logic describes the system organization 

 and the flow of information through the system; i.e. how the system oper- 

 ates on input data, what sequence of operations takes place, what the 

 pre-established tactical doctrine is for a given set of input variables, etc. 

 This structural element of the mathematical model provides the means 

 for breaking up the overall system function into logically consistent sub- 

 functions. 



4. System Configuration Parameters — These include the basic elements 

 and characteristics of the system needed to implement the system logic — 

 the geometry of the system, the number of weapons, the weapon character- 

 istics, and the capabilities and characteristics of each of the system elements 

 such as aircraft, radars, etc. 



5. Model Parameters — The basic model parameters are the time delays 

 that are defined for each of the system subfunctions on the basis of the 

 input parameters, the system logic, and the system configuration param- 

 eters. For reasons that were discussed in Paragraph 1-11, the time 

 interval associated with the performance of each function must usually 

 be expressed as a probability distribution of time delays rather than as 

 fixed time delay. 



Often, range to the target is used instead of time as the means for 

 expressing the basic parameters of the model. This is merely another 

 way of expressing the time delay, since range and time are related through 

 the relative velocity between the target and the weapon. 



Suboptimization. Most weapons systems are so complex that it is 

 not possible to construct a single model that includes all possible parameters 

 and variables. Instead, many different models must be constructed, each 

 designed to explore a certain facet of the system operating and its relation 



