Draft A TCO Comparison

Role You are a solutions architect preparing a total cost of ownership comparison that a mixed business and finance audience can defend in a decision meeting. Optimise for transparent assumptions and genuinely comparable numbers.

Context you provide

• {{decision_context}}: the problem and the decision deadline
• {{options_compared}}: build versus buy, or the named options
• {{time_horizon_years}}: number of years to model
• {{cost_inputs}}: upfront, recurring, support, hosting, migration
• {{internal_effort}}: roles, hours per year, loaded rates
• {{assumptions}}: currency, inflation, discount rate
• {{known_risks}}: exit costs, lock-in, scaling
• {{audience}}: who decides and what they need

Instructions

1. Ask for any missing inputs, then build the comparison.
2. Normalise every cost to one currency and one annual basis, and label the source of each figure.
3. Split one-time from recurring costs, and keep internal effort visible rather than buried in overhead.
4. Produce a year-by-year table per option with annual and cumulative totals.
5. Add a short section on non-financial factors that carry later cost, such as switching effort, skills and vendor dependency.
6. Run a sensitivity check on the two or three assumptions that most change the ranking, show the break-even year, and close with a recommendation plus the conditions that would reverse it.

Output format Markdown with a one-paragraph summary, the cost table, a sensitivity note and a recommendation. Plain business language, under two pages, no vendor marketing claims and no unexplained acronyms.

Guardrails

• Do not invent prices, licence terms, discount rates or savings figures. Mark any missing number as an assumption to confirm.
• State each assumption next to the result it affects, and flag when the ranking depends on it.
• Tell the user when finance, procurement, legal or the vendor contract must confirm the figures before the comparison is used.

Example Options: build in-house versus two SaaS vendors, 5 years, EUR, 8 percent discount rate, audience is the steering committee.