A business case justifies a product investment by comparing full costs against risk-adjusted benefits. The formula is Effective Monthly Benefit = Gross Benefit x Confidence % x (1 - Risk Haircut) - Monthly Run Cost, then ROI = (Total Benefit - Investment) / Investment x 100. Benefits are discounted by evidence quality (piloted 90%, benchmarked 60-80%, untested 40% or less) and delivery risk (low 0%, medium 15%, high 30%) because unvalidated benefits are the top reason business cases miss. As a working heuristic, a 3-year software business case typically needs about 15-20% per year in annualized return to win funding. PM Toolkit's free Business Case Wizard walks product managers from problem statement to a defensible verdict with payback period and NPV.
What is a Business Case?
A business case is a structured justification for an investment: the problem being solved, the full costs (one-time build plus ongoing run costs), the expected benefits discounted by evidence quality and delivery risk, and the resulting financial return.
Business Case Formulas
Effective Monthly Benefit = Gross Monthly Benefit x Confidence % x (1 - Risk Haircut) - Monthly Run Cost
ROI % = (Total Benefit - Investment) / Investment x 100
Payback Period = Investment / Effective Monthly Benefit + Implementation Months
When to Build a Business Case
Build a business case when securing budget for a major initiative, comparing build vs buy options, or defending a roadmap bet. Judge the result on annualized ROI so cases with different horizons compare fairly.
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Business Case Wizard
Walk from problem statement to a defensible business case — full costs, risk-adjusted benefits, and an ROI-backed verdict.
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Problem & Objective
State the problem, the proposed solution, and the horizon you are funding
To continue, fill in: Problem Statement, Proposed Solution, Strategic Objective, Analysis Horizon (months)
How to Build a Business Case That Gets Funded
A business case answers four questions in the order a budget holder asks them: what problem are we solving, what does the fix cost, what does it return, and how much of that return should we actually believe? This wizard walks those four steps and produces the numbers finance already trusts — annualized ROI, payback period, and NPV — plus a one-paragraph narrative you can paste straight into the funding doc.
Why Benefits Get a Haircut
Unvalidated benefits are the number one reason business cases miss. The wizard applies two explicit discounts to the stated benefit: a confidence haircut for evidence quality (a piloted benefit deserves 90%, an untested assumption 40% or less) and a risk haircut for delivery risk (0% low, 15% medium, 30% high). A case that clears the bar after both haircuts is a case that survives review.
Reading the Verdict
The verdict bands come from the same shared ROI engine as our ROI & Payback calculator, judged on annualized ROI so short and long cases compare fairly. A strong case clears 100%/yr equivalent returns with positive net benefit; a marginal case sits between 50-100%/yr and usually needs a strategic argument on top of the numbers; anything below — or any case with negative net benefit — is weak as framed and should be re-scoped.
Rules of Thumb for Funding Bars
- 3-year software cases: a typical funding bar is ~15-20%/yr annualized return; below 10%/yr the case competes poorly against other uses of the money.
- Payback: under 12 months reads as low-risk; beyond 18-24 months, market conditions may shift before break-even.
- Run costs count: a monthly run cost is subtracted from the benefit every month — cases that only count the build cost systematically overstate returns.
- Compliance cases: ROI looks weak by construction; present the cost of NOT acting (fines, blocked deals) as the benefit instead.
Business Case vs ROI Calculator
Use the single-page ROI & Payback calculatorto iterate quickly on one scenario's numbers. Use this wizard when you need the full argument — problem framing, cost accounting, benefit haircuts, named risks, and a narrative — in a form you can defend in a budget review. Both run on the same calculation core, so the numbers always agree.
What is Business Case (Risk-Adjusted ROI)?
A business case justifies a product investment in the terms budget holders compare: what it costs, what it returns, how fast it pays back, and how much of that return is believable. The key discipline is haircutting stated benefits by evidence quality and delivery risk before running the ROI math — unvalidated benefits are the top reason business cases miss.
Risk-Adjusted Business Case Formula
Effective Benefit = Gross Benefit × Confidence % × (1 − Risk Haircut) − Run Cost, then ROI = (Total Benefit − Investment) ÷ Investment × 100
Funding Bar Heuristic
A 3-year software case typically needs ~15-20%/yr annualized to win funding
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