Keep the original forecast
Save the forecast as it stood at the start of the period. Comparing a revised forecast with the final result can hide how much the expectation changed. Record which deals moved, changed value or were lost, and why.
Check what qualified for the forecast
For a sample of missed deals, ask what you knew about the buyer's need, funding, decision process and timing. A positive meeting may justify another conversation without justifying a place in the forecast. A no-decision outcome is a reason to investigate; it does not establish the cause on its own.
Look at the evidence behind each stage
Ask two people to assess the same opportunity. If they place it in different stages, clarify the criteria. Sending a proposal is an activity; the buyer confirming scope or explaining their approval process provides additional evidence. Review stage probabilities against comparable past deals where the records support it.
Review dates and values
Check the source of expected close dates and deal values. Ask whether the buyer has confirmed the timing, whether the scope has changed and whether the record has been updated. Quarter-end dates can be legitimate, but repeated postponements deserve a closer look.
Consider causes outside the sales process
A budget freeze, procurement delay, lost funding or change in leadership can affect a well-qualified opportunity. Keep these explanations separate from gaps in your own process so the review leads to a useful response.
Review the pattern over time
Compare several periods and investigate large individual misses. An average can hide offsetting errors. There is no single accuracy target established by this guide: the tolerance needs to reflect deal size, sales-cycle length and the decisions the forecast supports. The forecast calculator shows one way to compare periods.
Decide what to change
Record each change, its owner and the next review date. If you need help investigating the pipeline, read about the sales process audit.