Architecture Portal

Costing the alternatives

A service view over twelve months.

Adrian Sutherland · Version 1.0 · · © 2005–2026

Illustrative estimates

FN-D1 (Option cost comparison) compares three fictional options over the same twelve-month period. The figures are invented estimates in pounds sterling. Each total uses the same assumed cost basis.

Option Introduction Monthly operation Transition overlap Twelve-month total
Continue current working practice £0 £1,600 £0 £19,200
Process and ownership trial £2,400 £1,500 £0 £20,400
Later case-service option £9,000 £1,100 £1,500 £23,700

The total is introduction plus twelve months of operation plus overlap. Operation includes the assumed staff, supplier and technology costs. The case-service option costs more within this period even though its monthly estimate is lower. A longer period would require explicit assumptions about continued use, maintenance, replacement and the timing of expenditure.

What the total leaves open

Fewer unresolved cancellations might improve learner experience and staff capacity. Those benefits are unmeasured. Their owners need to specify how they would be observed and whether any reduction becomes a cash saving. Refunds, lost bookings and additional partner charges also need estimates before a real decision.

If monthly case-service operation were £250 higher than assumed, its total would rise by £3,000 to £26,700. Testing this assumption shows how a higher running cost would affect the comparison. The preferred option remains open.

Funding and feedback

FN-C1 (Funding commitment) would link each commitment to a funding owner and the architecture decision it supports. The service owner would review actual usage and costs, and revise the forecast when they differ materially from its assumptions. The management roadmap sets out the proposed sequence, and the customer view keeps the intended service outcome in the decision.

The financial record retains the scope, assumptions, calculation, benefit owner and next review. All options remain proposed; their costs and benefits have yet to be tested.

About this edition

Refreshed for the September 2026 website update. This edition develops the earlier Architecture Portal and ASAF material; the fictional worked example was added in 2026.

Scope, limitations and next checks

Status and accountability

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Status

In development

Last reviewed

Intended users

  • Architects comparing and adapting their existing approach

Non-goals

  • Prescribing a mandatory method or claiming measured benefits

Limitations

  • Guidance illustrated by a fictional example; proposed designs and checks have not been implemented or run.

Next evidence sought

  • Review the guidance and try its records with a practising architect.