I would like to create a spreadsheet to generate graphs about cost items (anything with a cost, doesn't matter what) in order to have:
- expected values: these would be created using some formulas to simulate future costs.
- actual values: these would be put in manually based on actual costs after billing.
At the end of a given time period (weekly, monthly...) the user would "freeze" the
expected value that was calculated earlier, and add the corresponding
actual value (and these should never be changed again).
The process would repeat itself for the next time periods while re-using either the same or new calculations for the expected values.
Over time, graphs will show the evolution of and different between the
actual values so as to allow for improvements (are the input values for calculations too optimistic / pessimistic?, were any cost items forgotten or not properly defined?...).
Can someone point me to a template from which I could create such a spreadsheet?