FinOps & process
Cost forecasting
Projecting future spend from the historical trend and known upcoming changes. You use it to catch a budget overrun before it happens, not after.
Last updated
Definition
Forecasting extends a spend trend forward, usually to the end of the current billing period. The team can then see whether current behavior will land within budget well before the period closes. A simple run-rate projection, the current daily average times the remaining days, is often good enough. Better forecasts account for known seasonality or planned changes, such as a feature launch or a committed-use purchase.
Forecast accuracy depends on how normalized and current the data is. A forecast built on stale or unreconciled numbers is confidently wrong. That is worse than no forecast.
A forecast helps only if the right people see it. Save it as a scheduled report. It can then arrive as a CSV or PDF each week or month. Nobody has to remember to check the dashboard.
Where it shows up
Cost forecasting appears as a projected total in a provider's billing console, such as the forecast view in AWS Cost Explorer. It extends the current daily average trend to the end of the billing period. It bases the projection on the days already spent in that period.
What makes it expensive
Do not trust a forecast built on stale or unreconciled data. It gives a confidently wrong number, not an honestly uncertain one. Before you quote any projection, find out how old the numbers underneath it are. A forecast inherits every problem in its inputs and reports none of them.
Related
The invoice is a lagging signal.
A monthly invoice tells you what already happened. CostMon builds a daily baseline, so a spike stands out while you can still act on it.