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64 deicing process, for example, relocating frost deicing from Table 42. User scenarios. remote deicing sites and central deicing facilities to on-gate deicing. Such a change may necessitate a capital expenditure Where/When Spot Frost Deicing Occurs for additional equipment, whereas the preliminary examina- Remote Gate Gate Location tion assumed there would be no need for such an expense. following prior to following scheduled scheduled Similarly, the preliminary examination assumed no change to scheduled departure departure departure deicing times and thus no effect on costs, whereas a relocation Remote Location Where/When Standard Frost of the frost deicing from remote facilities to on-gate deicing following A B C may have a considerable effect on aircraft block times, which scheduled departure are high value factors. Thus the final model incorporated sev- Gate eral parameters not included in the preliminary examination. following Deicing Occurs n/a D E scheduled departure Step 2: Cost-Benefit Model Development Gate and Testing prior to n/a F G scheduled The cost-benefit model went through several iterations departure before the final version was completed. The various aspects of the model and its functionality are described below. ations. The model categorizes the user's scenario by when and how both standard deicing and spot deicing will take place (determined by user input on the background page) according Model Objective to Table 42. The objective of building the cost-benefit model was to cre- For example, the cost to move frost deicing from a remote ate a model that can determine the number of years required location to gates is not applicable for scenarios A, D, E, F and to recoup the initial investment required to implement spot G. Therefore, "not applicable" appears in this cost input cell deicing for frost. The model does this by comparing the cost of (L18) when the user fits into this scenario. The cost input cells current (standard) frost operations to the cost of frost spot that are not applicable to the user's scenario are automatically deicing to determine the annual operational savings that will filled with "not applicable." be gained, and then comparing the annual savings to the initial Results: This page provides the results of the model analysis. investment required to determine the number of years until the The key results are the annual financial savings, annual glycol initial investment is recouped. savings, and number of years to breakeven. Breakeven Schedule: This page shows the annual change in cash flow year by year. The key item on this page is the year that Model Structure the initial investment (capital costs and setup costs) is paid off The model was developed as a Microsoft Excel workbook. by the annual operational savings. There are five worksheets (or pages) in the workbook. The user works sequentially from the first page to the last page, User Inputs Required following the instructions provided on the first page and at the bottom of each subsequent page. Specific instructions In order to complete the model, users must have the follow- and/or comments for some cells are provided in notes ing information available: attached to the cells. The content of each of the five pages is described below. Where and when standard/spot frost deicing are/will be Instructions: This page describes what the model will do, performed; provides general instructions for using the model, and provides Who (contractor or operator) performs/will perform a disclaimer about the use of assumptions in the model. standard/spot frost deicing; Background: This page requires user input. It contains a The amount of glycol used annually for frost deicing; number of questions to assess the current operation and to The annual number of frost deicings conducted; determine how the future spot deicing operation will be Whether new/different equipment will be required for spot conducted. deicing: Costs: This page also requires user input. The user is required Cost of new equipment required for spot deicing*; to enter costs under four categories: capital costs (new equip- Cost of new access equipment for spot deicing inspector*; ment), set-up costs, fixed annual costs, and variable annual Cost to gain in-house approval from all affected branches costs. Not all of the costs input cells are applicable to all oper- to proceed;