AI ROI · Template
The AI Business Case
A Board-Ready Template for 2026
Most AI business cases die in finance review for the same reason: they show only the upside, ignore adoption and capture haircuts, and don\u2019t set kill criteria. This template gives you the nine sections every defensible AI business case has, the build-vs-buy decision matrix CTOs and CAIOs actually use, and the ten questions every CFO will ask. Use it before funding, after funding, and at the quarterly review.
30-SECOND EXECUTIVE TAKEAWAY
- Co-author with finance. Business cases written by tech alone inflate value; written by business alone underestimate cost. Both signatures or neither.
- Set kill criteria up front. The 95% AI failure rate is partly a function of business cases that have no exit clause.
- Five to ten pages, not fifty. Length that exceeds the page limit usually hides weak assumptions in volume.
The structure that survives review
Most failed AI business cases share a structural defect, not a math defect. They lead with the AI tool instead of the problem. They show the upside without the haircuts. They cite vendor case studies as if they predict outcomes in a different organization. They don\u2019t document what would cause us to stop. They put the build-vs-buy decision into the appendix when it should be in the executive summary.
The nine sections below are what a defensible AI business case looks like in 2026. The structure works for productivity tooling rollouts, customer-facing AI features, agentic deployments, and platform investments. Adapt the depth per section to the size of the investment, but keep the structure intact. The order matters; finance reviews the early sections most carefully.
NINE SECTIONS
The standard AI business case structure
Each section is one paragraph to one page in the final document. Use the AI ROI calculator for section 4 and the AI risk management guide for section 6.
Problem & current cost
The specific business problem in measurable terms (e.g., support handle time, content production cost, sales cycle length). The current cost of not solving it.
Proposed AI solution
The specific solution. Foundation model, deployment pattern (RAG, agent, fine-tuned), integrations. One paragraph; this isn’t the architecture document.
Build vs buy decision
The choice and the reasoning. Off-the-shelf vendor, build on a foundation model, or hybrid. Decision matrix below.
Realistic ROI math
Annual benefit and cost with explicit adoption rate and productivity capture rate. Use the AI ROI calculator and document the inputs.
Total cost of ownership (3 years)
Tool cost, inference at production scale, integration, governance, change management. Year 1 is highest. Year 3 baseline is steady-state.
Risk register entries
Top 5–10 risks specific to this AI program. Includes prompt injection, accuracy mismatch, vendor lock-in, regulatory exposure. Each with owner and mitigation.
Success metrics
How we measure success at 3 months, 6 months, 12 months. Productivity, financial, adoption, accuracy.
Kill criteria
The specific signals that trigger restructure or termination. Set up front. Reviewed quarterly.
Governance & ownership
Business sponsor, technical sponsor, finance co-author, AI risk register entry, review cadence.
BUILD VS BUY
The build-vs-buy decision matrix
The build-vs-buy decision belongs in section 3 of the business case and in the executive summary. Use the matrix below to test the choice; most enterprises buy more often than they think they should and build less often than the technical team would prefer.
| Scenario | Recommendation | Reason |
|---|---|---|
| Common business problem, mature SaaS option exists | Buy | Faster time-to-value, lower TCO, vendor handles model upgrades and security |
| Differentiated use case, accuracy or domain-specific knowledge required | Build (on foundation model) | Off-the-shelf can’t hit your accuracy or domain-specificity requirement |
| Highly regulated industry, audit-grade evidence required | Build or specialized vendor | Generic SaaS often can’t meet sector-specific compliance; specialized vendors may exist |
| Need to integrate deeply with proprietary internal systems | Build (with vendor support) | Integration cost is the dominant TCO line; building gives flexibility |
| Productivity tooling for general knowledge workers | Buy (M365 Copilot, ChatGPT Enterprise, etc.) | No differentiation from building; vendor scale gives better economics |
| No ML engineering muscle in-house | Buy | Build creates ongoing maintenance burden the org isn’t resourced for; technical debt accumulates |
| Use case is core to the product or revenue model | Build or strategic partnership | Outsourcing the core competency leaves long-term strategic exposure |
CFO REVIEW
The 10 questions every CFO will ask
Pre-answer these in the business case before the meeting. A business case that doesn\u2019t address all ten won\u2019t survive serious finance review, and the questions that aren\u2019t addressed are the ones that get asked first.
- What’s the adoption rate assumption, and what data supports it?
- How does the inference cost scale from pilot to production traffic?
- What’s the productivity capture rate, and how was it calibrated?
- What’s the kill criteria, and who reviews it?
- What’s the contingency if the foundation model vendor changes pricing?
- How does this program fit alongside our other AI investments?
- What’s the regulatory exposure, and who owns compliance?
- What’s the change management investment, and how is it tracked?
- What’s the post-mortem trigger if this program underperforms?
- What’s the comparable benchmark from other organizations that have done this?
Run your numbers through the AI ROI calculator first. The defaults applied there are roughly the haircuts a thoughtful CFO will apply mentally during the review.
AI Business Case: Frequently Asked Questions
What goes in an AI business case?
How is an AI business case different from a software business case?
Build vs buy: how do I decide?
What’s the typical ROI horizon for an AI business case?
What kill criteria belong in an AI business case?
Who should own the AI business case?
How long should the business case document be?
Continue the AI ROI cluster
A defensible business case is the start. The calculator hardens the math; the failure-rate guide sets the kill criteria.