Different financial questions
To choose an option, decision-makers need to understand both the cost of introducing it and the continuing cost of running the service. A detailed infrastructure bill answers only part of that question.
| Approach | Contribution | Connection to examine |
|---|---|---|
| ASAF | A Simple Architectural Framework retains current, transformation and target financial models, with continuing controls. | Connect each model to the service and architecture it describes. |
| Green Book | UK government guidance for assessing costs, benefits and risks of options against objectives. | Use the applicable appraisal rules and explain uncertainty; the guidance has a public-sector scope. HM Treasury, 2026. |
| FinOps | Brings engineering, finance and business roles together around technology value, usage and financial accountability. | Relate technology spending to the service’s wider people, partner and change costs. FinOps Foundation framework. |
| Service cost model | Allocates recurring and changing costs to an agreed service scope. | Keep allocation rules, shared costs and benefits visible when comparing options. |
The rows compare selected concerns from the linked public guidance. The service cost model is a generic working technique. These approaches can be combined: an options appraisal informs a decision, while continuing cost and usage reviews test its assumptions.
A useful comparison
Ask whether a quoted saving includes staff effort, migration, support, retention, supplier exit and the timing of benefits. Describe non-financial outcomes even where no credible monetary value is available.
Methodology configuration
Map the financial records to your approval and budget process, using the organisation’s definitions of cost, benefit and commitment. Methodology configuration explains how to map terms, records and reviews to your own approach.
Use the financial example, then adapt the option and commitment record to keep comparable costs, assumptions and the decision together.