The following definitions apply: 



Dependability. Dependability is a measure of a system's convention- 

 ality, i.e., the amount the system exceeds the state-of-the-art. Since this is 

 an indication of the realizability and reliability of a system within the 

 allotted time frame, this figure of merit is assigned a relatively large weight. 

 Dependability is discussed in some detail in the section on the dependability 

 matrix. 



Mobility. Mobility is a measure of a system's capability to be moved 

 with relative ease. Self-propelled vessels are considered the most mobile. 

 However, because of increased power requirements, platforms are not con- 

 sidered as mobile as ships. Finally, any system independent of surface 

 support during operation, yet carried on a ship, is considered to have high 

 mobility. 



Since the only use of the system will be in underwater construction, 

 it is felt that the high degree of planning in construction projects decreases 

 the need for a rapidly deployabie system; thus, rapid transit between 

 construction sites will be unnecessary. Hence, a relatively low weighting 

 factor is assigned to this figure of merit. 



Extendability. Extendability is a measure of the possibility of 

 increasing the capacity of a system. For some systems, the probability of 

 increasing the weight, depth, or both is quite high. Also accounted for in 

 this figure of merit is the amount of reworking necessary to extend a 

 system's capacity. 



Extendability was given the minimum weight of one. While a 

 consideration for determining how quickly a system could become obsolete, 

 extendability must not be overemphasized if a system is to have well-defined 

 requirements and functional objectives. 



Covertness. Covertness refers to a candidate's capability to remain 

 undetected during an operation at sea. The success of presently undefined 

 military operations would perhaps depend on this factor. 



Rate of Lift. The rate of lift is self-explanatory. This figure of merit 

 is considered to be important since it indirectly indicates how long the lift 

 system must remain in operation on-station. The longer a system remains 

 on-station, the greater the chance of unfortunate changes in the weather. 

 Thus, it can be seen that the surface supported systems are particularly 

 vulnerable and some emphasis should be placed on how long it takes a 

 system to lift or lower a load. 



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