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en-USwww.sname.org/sname/mt en-USJuly 2012 en-US to get a picture of the design impacts on the O&S costs of the platform and provide sanity checks for operational concepts. Materially available vessel days may be used to assess operating and support costs per mission day. Figure 2 shows the operational prole tab of the program prole input form in the ship model. is allows the schedule and types of depot maintenance to be dened and for deployed periods (which usually have higher steaming hours) to be specied. Additional metrics highlighted on this form alert the analyst to how much of the service life a platform is expected to spend in depot main -tenance, deployed, and non-deployed states. ere is also a built-in display that serves as a logical check, alerting users to impossible or improbable operational proles. The user interface is used to specify values for all inputs used by the system dynamics model. Many sectors have options for two alternative representations of detail, referred to as ?simplied? and ?detailed? within the model. is type of facility is used throughout the input forms to give exibility in how OSCAM is used. e simplied options enable OSCAM to be used earlier in the acquisition process (including the concept phase) when fewer details are known. e study can then grow into the detailed representations as more information on the program is developed. Once an analyst has dened all of the inputs that describe the operational and cost behavior of the platform, OSCAM is used to simulate the service life of the platform class. OSCAM systematically follows the platform through each month of the service life and captures the costs associated with its operational state at the given time. It is possible to specify that cost outputs will only be shown after a speci -fied year, which is useful for analyzing platforms that are already in service. A simulation run takes approximately 3 sec -onds on a modern PC. e results form displays annual val -ues on the table and provides a graphical view for any selected results line. The table uses the OSD O&S cost element work breakdown structure and numbering for the cost elements and also shows the non- cost outputs. e table can be expanded to a desired level of detail. e results form enables multiple sets of results to be dis -played as represented by separate tabs. Multiple results sets can be compared using the graphical view. All results from simulation runs are produced in millions of dollars ($M) using a user-dened xed-cost base year (that is, without ination). Additional analysis tools are provided for the results form: Delta tool: enables one set of results to be subtracted from another to highlight the dierences Aggregation tool: enables several sets of results to be added together The year $ tool: applies inflation for each year (using appropriate ination cat -egories for dierent types of output such as fuel, personnel, and parts) to determine the expected dollar cost in that year. In addition to the tools for analyzing results on the results form, there are also tools that make use of repeated runs for ana -lyzing the relative impact of inputs and for incorporating uncertainty in input values. e uncertainty tool enables probabil -ity distributions (11 types) to be specied for any number of inputs. e tool will per -form repeated runs, sampling the input values to be used throughout that run. Supporting data The navy uses a relational database called VAMOSC (visibility and management of FIGURE 2: INPUT FORM FOR SHIP OPERATIONAL PROFILE Not only are O&S costs typically much larger than procurement costs, but the majority of those costs become locked in during the design phase.