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Test two uncertain inputs together before approving a financial plan

Use a sensitivity table to see which combinations meet the decision threshold. Distinguish possible combinations from probabilities and preserve the model's cost relationships.

By Institution3 minute readPublished View sources
In this guide

Choose inputs that can change the approval

A plan may survive a modest reduction in customer volume and a modest reduction in contribution when each is tested alone, yet fail when both occur. Select two uncertain inputs that matter to the decision and examine their combinations. The table should help management understand where its approval conditions hold.

Microsoft's What-If Analysis documentation describes data tables that substitute values for one or two inputs and report the formula's outcomes. That tool can support the exercise, but the input choice and commercial interpretation remain the analyst's responsibility. A large grid of arbitrary percentages does not improve weak assumptions.

State the output and threshold first. You might test whether annual contribution covers a specified operating commitment or whether investment value remains positive. Use one clearly labeled measure, with its period and exclusions, so readers can interpret every cell consistently.

References: Microsoft: Introduction to What-If Analysis

Read the boundary in a simple example

Assume a hypothetical service initiative has $42,000 of annual fixed cost. Uncertainty concerns the number of customers served and annual contribution per customer after variable delivery costs. At 70 customers and $800 each, the modeled result is $14,000. The table shows other combinations using the same fixed commitment.

At 50 customers and $800 contribution, the initiative loses $2,000. At 70 customers and $600, it breaks even. These outcomes do not state how likely each combination is. They identify what must be true for the simplified plan to cover its fixed cost before tax, financing and other excluded items.

Read the boundary in a simple example
Hypothetical annual customers$600 contribution each$800 contribution each$1,000 contribution each
50($12,000)($2,000)$8,000
70$0$14,000$28,000
90$12,000$30,000$48,000

Keep combinations economically coherent

Ask whether the inputs are independent. Higher customer volume may require discounts, create a different service mix or trigger extra fixed capacity. If those relationships matter, the model should recalculate them or identify cells where the simple assumption no longer holds. Do not display impossible combinations as equally plausible business cases.

Retain the meaning of contribution. If customer count changes, variable delivery cost should change with the appropriate driver. If the analysis instead varies realized price, ensure the cost per customer remains separately defined. A table can give correct arithmetic while quietly changing the metric being tested.

Use ranges grounded in commercial evidence. Review contracted demand, historical outcomes and identified cost uncertainty. If a range is management judgment, label it that way. Avoid describing a green area as an 80% chance of success unless a separate, supported probability model establishes that conclusion.

Use the table to direct the next piece of work

Locate the approved case and identify the nearby combinations that would change the decision. If the result depends mostly on achievable contribution, investigate delivery cost and realized terms. If demand determines the outcome, commission the customer evidence needed to narrow that uncertainty. The table should identify a practical information gap.

Test the workbook itself by calculating at least one corner and the central case independently. Confirm that both inputs reach the intended model cells and that outputs refresh. Save the input definitions and version with the result so a pasted table can be traced to its calculation.

Agree what observation will trigger a new review after launch. Management may decide to proceed conditionally, reduce scope or obtain more evidence. Record that action beside the relevant boundary instead of treating the preferred central cell as the only result worth discussing.

Sources

Requirements and product details can change. Check the linked guidance for the facts that apply to your situation.

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