Use a forecast to test a decision.

Summit Strategy perspective

A forecast is most useful when it helps management compare choices. The starting point is the decision ahead and the assumptions that could change it.

Frame the commercial question first

A request for a forecast can hide several different questions. Can the business support a proposed expansion? How would a change in demand affect operating capacity? What cash timing does a new contract create? Which costs are likely to change with volume?

The model should reflect the question. A broad annual budget may be appropriate for planning, while a capacity decision could require a more detailed view of volumes, timing and resources. The required detail should serve the decision rather than make the workbook larger.

Know what the available data can establish

Accounting records provide a foundation, but they may not explain the operating drivers behind the numbers. For example, revenue does not establish how many customers were served, which services used capacity or how much repeat business occurred.

Before modelling, clarify the period, the source and the meaning of the inputs. Check how actual results reconcile with the starting position. Where operating data is missing, record the gap and decide how it affects the analysis.

A model should preserve the difference between observed information, management estimates and planning assumptions. Combining them without explanation makes the output harder to assess.

Keep assumptions visible

Management should be able to find and challenge the assumptions without tracing every formula. Separate the controls from the calculations and label the units and periods clearly.

Useful assumptions often concern demand, pricing, mix, resource requirements and timing. Their relevance depends on the business. A model should also make the relationship between profit and cash explicit where that matters to the decision.

Compare coherent scenarios

A scenario is a set of assumptions that fits together. Increasing sales without examining capacity, service requirements or collection timing can create a misleading picture.

Compare a manageable number of scenarios with clear reasons for their differences. Explain which inputs changed, why they changed and what remains uncertain. This lets management discuss the commercial conditions rather than debate unexplained spreadsheet results.

Testing one assumption at a time can also help identify which variables most affect the result. Use this to focus further investigation and management attention.

Define the next decision and review point

A forecast should lead to a decision, a further evidence request or a condition for proceeding. Leadership may decide to stage the commitment, gather more operating data or set a trigger for reconsideration.

1. State the decision the model supports.
2. Show the starting position and the main assumptions.
3. Compare the options and explain the material differences.
4. Identify the constraints, risks and evidence gaps.
5. Agree what management will review and when.

The forecast is a structured view of possible outcomes under stated conditions. Its usefulness comes from how clearly it connects those conditions with the choice management needs to make.

This perspective provides general planning considerations. The appropriate approach depends on the circumstances and evidence in your business.