Drill Bit Replacement Spreadsheet Model

Open the Drill Bit Replacement example, shown in Figure 58, Drill bit replacement problem spreadsheet model, below. This workbook has Crystal Ball assumptions defined for:

Table 12. Drill Bit Replacement model assumptions

Cell	Assumption
C6	Replacement time, R.
C8	Drilling depth function coefficient, C.
C10	Number of days available per month, D.

One decision variable is defined in cell C12: the cycle time between replacements of the drill bit, T.

Figure 58. Drill bit replacement problem spreadsheet model

The model outputs are computed using the formulas developed in the previous section. The drilling expenses in cell F7 include both the drilling costs and the replacement costs. The forecast cell is F12, profit per month.