For the MOBS concepts under investigation, the important cost 
elements include R&D, fabrication, storage costs (if applicable), 
transportation to site of operations, assembling (CONUS or remote), out- 
fitting, annual operating, and maintenance. Salvage value, if useful 
life exceeds operational life, should also be a consideration. The 
value for these cost elements should be based on best estimates from 
contractors and knowledgeable experts. 
The overall cost would be the sum of the above cost elements with 
present value factors applied where appropriate. It will be possible 
to vary the size of the cost elements to determine how sensitive the 
total cost is to changes in subsystem costs. Maintenance costs, opera- 
ting costs and storage costs will probably be about the same for all 
configurations. Costs for research and development, fabrication, 
transportation, and assembly are functions of the configurations and 
will be varied between reasonable limits to possibly expose critical 
components and/or procedures. 
Where possible, the cost of improving a candidate's effectiveness, 
i. e., increasing its total worth according to the predetermined 
performance criteria, should be noted and the results discussed in suf- 
ficient detail to demonstrate what tradeoffs are possible and what key 
risks are associated with any particular system. This approach should 
provide some, if not all, of the information needed to evaluate the 
the ''cost-effectiveness" of a given system for the (as yet) undefined 
missions. 
Analysis 
Candidate systems should be compared on at least two levels. The 
first objective would be to select one of the candidate MOBS base con- 
cepts for further evaluation. The approach should be to use all pre- 
viously generated performance records and cost estimates in evaluating 
each base concept's relative worth, i. e., determining how nearly a 
candidate meets what are considered desirable MOBS performance goals. 
A suitable scheme which reflects the relative importance of the per- 
formance goals should be used in scoring the candidates (for example 
see Miller, 1967 or WSEIAC, 1965). Figure 6.1 outlines the selection 
methodology and indicates the crucial role played by the performance 
record in the selection process. 
The first-level trade-off analysis can be conducted early in the 
MOBS program. The performance record need not be as precisely defined 
as that which will be required for comparing alternatives within a 
base concept category. 
After selection of the most desirable base concept for each MOBS 
mission and after completion of necessary studies to construction a 
meaningful performance record for base concept alternatives, a second 
comparative analysis would be conducted to finalize the prototype MOBS 
design. In this second trade-off, the optimum buoyant support system, 
most efficient deck design, best assembly methods, and other critical 
options would be determined and finalized. 
6-5 
