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A tall wall of clear glass onto the sea, braced by slender steel rods that all pass through one small hub holding a disc of sapphire glass. Five rods are shallow; one is much steeper and runs from the ceiling down to an anchor in the stone floor.

Feasibility study sensitivity analysis

See which assumption your answer turns on.

Try the explorer
What the film shows, in words
  1. See which assumption your answer turns on.
  2. A plant costing USD 250,000. Net present value: USD 190,330.
  3. Year-1 revenue moves it most: USD 42,652 to USD 338,007.
  4. If year-1 revenue could be 30% lower: −USD 31,187. One assumption flips the answer.
  5. At USD 120,000 in year 1: the base case is −USD 55,800.
  6. Find the assumption that decides. Then test it with evidence.

The demo: the worked example, one input changed at a time

ExampleStep 1 of 4A small processing plant with illustrative figures, not a real project.

Six assumptions, each tested alone. None reaches zero.

1Year-1 revenue6Revenue growth4Initial investment2Variable cost share3Fixed costs5Discount rate

Base case USD 190,330. Year-1 revenue alone moves it from USD 42,652 to USD 338,007. Four assumptions moved together: −USD 130,575 to USD 543,041.

The tool’s finding: “The answer flips between the low and high cases (±20%).”

Year-1 revenue at USD 144,000 and USD 216,000 gives USD 42,652 and USD 338,007. Alone, it brings the result to zero at about −25.8%.

Each rod is one assumption moved alone, by a percentage of its own value. The steeper the rod, the more that assumption moves the result. Choose a rod, or its name, to read its two ends.

The rail at the right is a different test: investment, year-1 revenue, variable costs and fixed costs all moved together. Growth and the discount rate stay where they are.

Arithmetic on the example’s assumptions. Not a forecast, and not a recommendation to invest or not to invest.

Now your assumptions. Which one decides?

Live

What comes in

USD

Moves the result most. Tested at USD 144,000 and USD 216,000

% a year

Sixth of six. Tested at 6.4% and 9.6%

years

Not tested

USD

Not tested

net present value, base case
USD 190,330
internal rate of return
28.0%
simple payback, not discounted
3.6 yrs
low to high case, ±20%
−USD 130,575 to USD 543,041

Arithmetic on these assumptions. Not a forecast, and not a recommendation.

1Year-1 revenue6Revenue growth4Initial investment2Variable cost share3Fixed costs5Discount rate

Year-1 revenue at USD 144,000 and USD 216,000 gives USD 42,652 and USD 338,007. Alone, it brings the result to zero at about −25.8%.

What goes out, what you require

USD

Fourth of six. Tested at USD 200,000 and USD 300,000

% of revenue

Second of six. Tested at 28% and 42%

USDa year

Third of six. Tested at USD 48,000 and USD 72,000

%

Fifth of six. Tested at 9.6% and 14.4%

The tool’s first finding

The answer flips between the low and high cases (±20%).

The rail is a different test: investment, year-1 revenue, variable costs and fixed costs all moved against you, then all in your favour, by ±20% together. Growth and the discount rate stay where they are.

Each assumption is moved by a percentage of its own value, not by percentage points: a rate of 12% tested by ±20% runs from 9.6% to 14.4%.

An assumption set to zero cannot be moved this way, so its rod has no length. Project life and residual value are not tested at all.

Past each edge a rod runs on, faint, to where the tool puts it at the frame’s own range. Under the floor it turns to the warning colour. The level lines mark equal steps of value.

The full result

The cumulative discounted cash flow, year by year. Then the same six tests as the rods above, read as ranked bars: one test, not a second analysis. Then the base-case table and what the tool finds. The payback above is simple, not discounted, so it can differ from where the discounted line crosses zero.

USD190,330net present value, base case
28.0%internal rate of return
3.6 yrssimple payback
−USD130,575 to USD 543,041NPV range at ±20%
Cumulative discounted cash flow (USD)
-300k-89k122k332k543kY0Y2Y4Y6Y8
  • Base
  • Low case
  • High case
What moves the NPV most (each assumption ±20%, others at base)
  1. Year-1 revenueUSD 42,652 to USD 338,007
  2. Variable cost shareUSD 269,848 to USD 110,811
  3. Fixed costsUSD 249,941 to USD 130,718
  4. Initial investmentUSD 240,330 to USD 140,330
  5. Discount rateUSD 236,819 to USD 150,068
  6. Revenue growthUSD 155,152 to USD 227,593

Line: base case, USD 190,330.

Base-case cash flow
YearRevenueCostsNet cash flowDiscounted
Year 0USD 0USD 250,000−USD 250,000−USD 250,000
Year 1USD 180,000USD 123,000USD 57,000USD 50,893
Year 2USD 194,400USD 128,040USD 66,360USD 52,902
Year 3USD 209,952USD 133,483USD 76,469USD 54,429
Year 4USD 226,748USD 139,362USD 87,386USD 55,536
Year 5USD 244,888USD 145,711USD 99,177USD 56,276
Year 6USD 264,479USD 152,568USD 111,911USD 56,698
Year 7USD 285,637USD 159,973USD 125,664USD 56,844
Year 8USD 308,488USD 167,971USD 140,517USD 56,753

What the numbers say

  • Check: The answer flips between the low and high cases (±20%).Evidence for “year-1 revenue” matters most. Firm it up before deciding.
Your full reportScenario comparison and sensitivity tableTry this form

Practice 01: Research, evidence & evaluationFree · instant results on this pageTool owner: Michael Gagakuma and Prof. Wisdom GagakumaVersion 1.0 ·

GKM Strategic Advisory & AI

Scenario comparison and sensitivity table

Your organisation

NPV (base)
USD 190,330
IRR
28.0%
Top driver
Year-1 revenue

PDF · 24 September 2026

Base-case cash flowXLSX

YearRevenueCostsNet cash flowDiscounted
Year 0USD 0USD 250,000−USD 250,000−USD 250,000
Year 1USD 180,000USD 123,000USD 57,000USD 50,893
Year 2USD 194,400USD 128,040USD 66,360USD 52,902
Year 3USD 209,952USD 133,483USD 76,469USD 54,429
Year 4USD 226,748USD 139,362USD 87,386USD 55,536
Year 5USD 244,888USD 145,711USD 99,177USD 56,276
Year 6USD 264,479USD 152,568USD 111,911USD 56,698

and 2 more years

The first page and the first sheet as they stand, on the assumptions above. Both change as you change them.

Your full report

Scenario comparison and sensitivity table, by email once delivery is connected.

Scenario comparison and sensitivity table (PDF + spreadsheet) with your assumptions stated

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How it is worked out, and its limits.

One assumption is adjusted while the others are held. The formulas are published so you can check them.

Method

  1. 01

    Revenue grows at a constant rate; variable costs are a share of revenue; fixed costs are flat each year.

  2. 02

    NPV = −investment + Σ net cash flow ÷ (1 + discount rate)ᵗ. IRR is the rate at which NPV is zero, found by bisection.

  3. 03

    Low and high cases move revenue, costs and investment against or in your favour by the test range together; the tornado moves one assumption at a time.

What it cannot tell you

  • Pre-tax, in nominal terms, without financing, working capital or inflation effects.
  • It shows what follows from your assumptions; it is not a forecast or an investment recommendation.
  • A real feasibility study tests the assumptions themselves with evidence.

Quality ruleRecalculate deterministic fixtures; no investment recommendation.

Close on the hub under the canopy: a machined steel ring with steel rods meeting it from every side, and a disc of sapphire glass at the centre. The sea lies beyond.
One rod is adjusted while the others are held: the method in one object.
The foot of a steep steel strut where it lands on a stone block, with an upright strip of sapphire glass set in the wall beside it and the sea beyond.

The explorer finds the assumption. A study tests it with evidence.

A real feasibility study tests the assumptions themselves with evidence. These are the services that do that work, and the people who lead it.

Feasibility studiesService · 01 Research, evidence & evaluationFinancial analysis, modelling & cash-flow scenariosService · 09 Data, analytics & automation 01 Research, evidence & evaluationPractice Survey sample-size plannerFree toolSource & evidence register builderFree toolGhana market-entry question plannerFree tool
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