A model is not there for the presentation, it is there for the decision: buy this type or the other one, add a second aircraft or build up the hours on the first, open this route or leave it alone. We count the way an operator counts, not the way a consultant draws it.
A working model in a spreadsheet that stays usable after we are gone: change the annual flight hours, the rate or the make-up of the fleet and you see the result. Plus an explanatory note: where the assumptions sit, where the figures came from and which of them need rechecking when the market moves.
The model is built for whoever will read it. An investor cares about returns and risks; a bank or a lessor cares about the resilience of the cash flow; you care about exactly where the business earns and where it leaks.
This is the core of the model, and it is where mistakes are made most often: direct costs are taken and reserves are forgotten. An hour in the air uses up life, and if nothing is set aside for heavy work, the handsome economics of the first year turn into a cash gap in the third.
For three things: to take decisions on fleet and network, to raise financing, and to manage the economics once you are running. A model without the last of these is just a presentation.
Usually two to six weeks, depending on the size of the fleet, the number of routes and how complete the source data is.
Yes. The economics of a single aircraft under management follow the same logic — the model is simply shorter.
Describe the situation — I answer personally and to the point.