Cost of inaction
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Expected present value over ten years
Decision tool · single-system investment diagnostic
Cost of Inaction Diagnostic
Put a board-level financial frame around the decision to defer a technology investment, before operating drag, risk and constrained growth turn an avoidable choice into a forced transformation.
Directional starting case. Complete the eight-question scan to generate a financial figure. The range narrows as estimates are replaced with evidence.
Plausible range
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P10–P90, excluding the separate stress cases
Investment wins
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Share of simulated outcomes above £0
Evidence confidence
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Evidence quality, not statistical certainty
Economic cost: business as usual vs invest now
Present value over ten years · corner cases shown as stress tests
Business as usualInvest now
Stress-test table
These deliberately stack assumptions; they do not define the plausible range.
| Case | Cost of inaction | Payback | Constraint point |
|---|
Capacity constraint view
Demand versus sustainable capacity · red gap labels show annual profit exposed
Business demandBAU capacityInvest-now capacityProfit exposed
What drives the Base case
Present-value contribution to the result
Ask what people can observe. The model derives the technical and financial assumptions behind the scenes. Mark each answer as estimated, observed or verified; this changes evidence strength, not the answer itself.
Advanced assumptions and audit trail
Reduce the range by learning, not by negotiating the numbers. These are the assumptions currently creating the largest financial swing. Contributions overlap, so they should not be added together.
Next best evidence to collect
Ranked by one-at-a-time movement in Cost of Inaction
Suggested evidence sprint
- Pull revenue, margin and current system spend from management accounts.
- Sample workaround time for two representative weeks.
- Review twelve months of incidents, delays and recovery effort.
- Connect transaction-volume growth to an observable system limit.
- Obtain a vendor estimate and compare it with one similar implementation.
Range discipline
Known company facts stay fixed. The plausible range comes from repeated draws across uncertain assumptions and is reported as P10–P90. Fully stacked Low and High cases remain visible only as stress tests.
Strategic case
Why must the organisation act, and which growth or control objective is the current system blocking?
Economic case
Does invest now create more present value than business as usual across plausible scenarios?
Commercial case
Can the market supply the required capability, migration, support and exit terms?
Financial case
Can the company fund implementation, transition and recurring costs without creating liquidity stress?
Management case
Who owns adoption, benefit realisation, data migration, controls and post-launch measurement?
Board questions the number cannot answer alone
- Which constraint is observable today, and what evidence would prove it is approaching?
- What has to change in process and behaviour for the technology benefit to appear?
- What tail risk matters even if its expected value is modest?
- What option does this investment create: scale, speed, data, AI readiness or acquisition integration?
- At what trigger point will management revisit a decision to defer?
Recommended decision language
Minimum evidence pack
- Management accounts and growth plan
- System, incident and workaround cost records
- Transaction-volume and capacity evidence
- Vendor support / end-of-life position
- Implementation estimate and comparable-project forecast error
- Named benefit owners and measurement plan
Core equation
Cost of Inaction = PV(BAU economic costs) − PV(Invest-now economic costs)
BAU economic costs
Legacy run cost + manual work + expected incident loss + forced remediation + constrained contribution.
Invest-now costs
Implementation + transition + new run cost + residual manual work + residual risk + any remaining constraint.
Decision rule
Positive supports investing now. Negative supports deferral within quantified scope—subject to tail risks and strategic options.
Range and confidence safeguard
The plausible range is the 10th to 90th percentile from deterministic simulation across uncertain assumptions. Fully stacked extremes are reported separately. Evidence strength combines the quality of supporting data with the remaining width of that P10–P90 range; it is not a statistical confidence interval.
Research foundations
Architecture informed by HM Treasury Green Book options appraisal and optimism-bias guidance; NIST SP 800-30 likelihood/impact risk decomposition; empirical technical-debt principal/interest research; and capability-based real-options approaches to IT investment. Full citations are retained in the companion workbook.