Choose one comparison period and scope. Separate direct spending from internal effort, and state any conversion rate. Use low, expected, and high scenarios with reasons.
Tool / owner / comparison period:
Prepared by / reviewed by / date:
Internal rate and source, if converting time to money:
Unit of work the tool produces (for example, one report, one onboarding, one reconciled record) and expected volume over the period:
Cost categories
| Cost category | One-time or recurring | Direct cost range | Internal hours range | Assumption / source | Owner |
|---|---|---|---|---|---|
| Requirements and delivery | One-time | ||||
| Integration and acceptance | One-time | ||||
| Hosting / services / usage-based fees | Recurring | ||||
| Licenses and third-party components | Recurring | ||||
| Access and support | Recurring | ||||
| Security / dependency updates | Recurring | ||||
| Monitoring and incident handling | Recurring | ||||
| Business and provider changes | Variable | ||||
| Handover | Variable | ||||
| Retirement / migration, including data export and deletion | Exit |
For the chosen period, add one-time delivery, the period's recurring costs, planned change, and applicable exit costs. Count each item once. Multiply hours by the stated rate only when a monetary comparison is needed.
Total for the period (low / expected / high):
Cost per unit of work at expected volume:
Scenario drivers:
Comparison
| Alternative | Total for the same period | Cost per unit | Capability difference | Exit difference |
|---|---|---|---|---|
| Keep the current tool | ||||
| Purchased product | ||||
| Do nothing / manual |
Benefit or avoided cost claimed, kept separate from the cost figures and stated with its evidence:
Handover check
- [ ] Source, accounts, configuration, and dependencies have appropriate ownership.
- [ ] Another person can operate, diagnose, and recover the tool.
- [ ] Credential locations are documented without exposing secrets.
- [ ] Recurring costs are visible to the owner (invoices, usage dashboards, alerts on unexpected spend).
- [ ] Unused resources and licenses were checked in the period and released.
Tracking
| Check | Cadence | Last done | Forecast vs actual |
|---|---|---|---|
| Recurring spend reviewed against forecast | |||
| Internal hours sampled | |||
| Volume of work compared with assumption |
Common failure modes
- Delivery is costed and operation is not.
- Usage-based fees grow with adoption and nobody watches the invoice.
- Internal hours are counted only for the builder.
- The exit cost is discovered when the exit is already necessary.
Comparison result / unresolved estimate / next review:
This worksheet covers cost. It does not decide value or fit; pair it with the build, buy, or combine memo.