Software Purchase Business Case

When to use it

The user wants a tool, a licence or a system and has to get the money approved. They have, or can get, the vendor's price and some idea of what the current way costs. They need a case a finance lead will read without rolling their eyes: counted benefits, total cost over the term, payback, and what happens if nothing changes. One tool, one case, one page.

Not for: comparing three vendors (that is a selection, and the case comes after), building a company-wide budget, or a tool with no measurable benefit. If the only benefit is "the team would like it", this skill says so and stops.

What it asks you

Ask for these in one message, numbered:

1. The tool and what job it replaces or changes.
2. Vendor costs: recurring (per month or per year, per seat or flat), one-time (implementation, migration, setup), contract term and notice.
3. Hours today: who spends how many hours a week on the job the tool changes, and the loaded hourly cost the company uses for them. If they do not know the rate, ask for salary and on-costs and compute it, or write "rate: not given".
4. Errors today: how many a month, and what each costs to put right (cash fees, rework hours, refunds).
5. Revenue, only if the tool changes it: what, how much, and how they know.
6. Any cash cost that goes away: overtime, a contractor, a licence the tool replaces, penalties.
7. Training hours per person and how many people. Go-live date or how many months until benefits start.
8. Who approves, and what they have said matters (cash, headcount, risk).

Work from what comes back. One follow-up for a vague figure ("about a day a week" becomes "how many hours, for how many people?"). No figure given: the benefit line reads "not given" and does not enter the arithmetic. Never invent an hourly rate, an error count, a revenue effect or a vendor price.

What comes back

Plain text. Headings in capitals.

RECOMMENDATION Go, Go with condition, or Wait. One sentence with the rule that fired and the condition if any.

DOING NOTHING Each cost line with its sum. Hard subtotal, soft subtotal (labelled capacity), monthly and yearly total.

THE TOOL Recurring, one-time, training, migration, term. Total cost over the term.

BENEFIT AND PAYBACK Monthly benefit, hard and soft. Net monthly benefit. Payback months at full, half and cash only, each with the division shown. Benefit over term against cost over term.

ALTERNATIVES RULED OUT One line each, or "not considered" where the user did not say.

RISKS One line each with the mitigation or "mitigation: not given".

QUESTIONS Figures not given and anything the approver will ask.

Next: one line naming the single most useful next step.

• 00_START_HERE.pdf: the two-minute set-up for each AI.
• 1 - Skill: software-business-case-payback.zip, one upload to Claude, ChatGPT, Gemini, Grok or Microsoft 365 Copilot. It switches on by itself when this job comes up.
• 2 - Text file for any AI: the same Move as one .txt. Attach it to any chat, on any plan, and type "Follow this file".

It drafts, you read and send. It never contacts anyone for you and never invents a fact, a number or proof.

A Move is a single play. The whole function in a box is an agent pack.