# What makes a technology business case credible?

By Sean Everett · October 6, 2026

Connect a scoped technology change to specific benefits, a complete resource plan and a realistic observation period. Compare alternatives on consistent assumptions and keep projected benefits separate from evidence of actual improvement.

Topics: Technology planning · Business cases · Benefits measurement

## Define the change and the comparison

State the operating problem, the people affected and the intervention being considered. Explain what would happen if current arrangements continued, including required maintenance or foreseeable constraints. Compare the proposal with a smaller workable response so the business case can reveal which additional work is justified.

HM Treasury's Green Book uses a business-as-usual comparison and asks how a proposed intervention produces its intended outcomes. It is guidance for public-sector appraisal, including social value. The transferable planning discipline is to make the comparison and causal explanation explicit before attaching numbers to the proposal.

Distinguish intended benefits such as customer retention, additional sales, released working time and reduced operational risk. Give each a measure, an owner and a realization condition. A platform release may enable a benefit while leaving adoption, process changes or retirement of an old system still to be completed.

## Build the resource estimate alongside the benefit estimate

Estimate the work required to deliver and operate the change. Include internal time, specialist help, migration, training, parallel operation and ongoing support. Record which costs are already committed and which depend on the decision, then have the responsible finance team apply consistent treatment across the options.

GAO's Cost Estimating and Assessment Guide calls for a defined scope, technical baseline, work breakdown, assumptions and uncertainty analysis. It also includes updating estimates with actual costs. Use those elements to make an estimate inspectable: a reviewer should be able to trace a total back to identifiable work.

Keep absolute resource needs visible beside ratios. Development spending as a share of revenue can fall because revenue rises, without any reduction in development effort. Check the underlying workload, staffing and revenue assumptions before describing the change as improved efficiency or using it to support a larger commitment.

## Identify the evidence that would change the decision

Test the assumptions most capable of changing the preferred option: implementation duration, adoption, ongoing effort or the size of the affected workload. Treasury's guidance explicitly addresses optimistic estimates of costs, benefits and timing. Use relevant evidence about earlier estimates where available instead of assigning confidence because a spreadsheet is detailed.

Avoid counting the same operational change twice. Time released for additional work and reduced staffing expense are different possible uses of that capacity. Specify the intended use and the action needed to realize it. Keep risk reduction described in terms the available evidence can support.

When demand falls, compare a continued-slowdown scenario with a plausible return of work for each affected service. Record which changes remove recurring work and which merely defer it. For paused tools or supplier arrangements, include the work and lead time needed to restart, with assumptions checked by the operating owner.

NIST’s contingency-planning guidance connects recovery priorities with resource requirements and dependencies for information systems. Apply that planning question to a proposed operating pause: what must still be available when work returns? Keep restoration effort visible in the comparison and identify evidence that would trigger reconsideration of the pause.

Set a review point around an informative milestone, with the evidence required to continue, narrow or stop the work. After implementation, compare observed costs and benefits with the dated case, including unmet prerequisites. Preserve that comparison so future proposals can learn from the difference between expectations and delivery.

## Related reading

- [HM Treasury: The Green Book 2026](https://www.gov.uk/government/publications/the-green-book--2/the-green-book-2026)
- [GAO: Cost Estimating and Assessment Guide](https://www.gao.gov/products/gao-20-195g)
- [Connecting technical findings with product priorities](https://evergences.com/insights/technology-assessment-product-priorities/)
- [Making operating measures useful for decisions](https://evergences.com/insights/operating-metrics-decisions/)
- [NIST: Recovery resource requirements and dependencies](https://nvlpubs.nist.gov/nistpubs/Legacy/SP/nistspecialpublication800-34r1.pdf)

Source: https://evergences.com/insights/technology-investment-business-case/