Project Contingency Planner methodology

expectedRiskCostExTax = risk 1 probability × impact + risk 2 probability × impact

rateFloorExTax = project base cost × minimum contingency rate

recommendedContingencyExTax = maximum of expected identified risk cost and minimum rate floor

protectedCostExTax = project base cost + recommended contingency

Money inputs and outputs use the currency selected in the scenario without changing the canonical methodology. Rates, margins, utilisation and buffers are entered as percentages and converted to decimal values for calculation.

• All values must be finite and remain inside the visible input boundaries.
• All money values use one consistent ex-tax basis and period.
• Rates must remain inside their engine-owned boundaries.
• The two fixed risk rows remain distinct; each probability is multiplied by its own entered impact.
• The selected contingency is the greater of expected identified risk cost and the entered rate floor.
• Low, base and high identified-risk review — Low: Enter a plausible lower-exposure version of the same identified risks, changing probability or cost impact only when the project evidence supports it.
• Low, base and high identified-risk review — Base: Use the current risk register values that are most defensible for the quoted scope and delivery plan.
• Low, base and high identified-risk review — High: Enter a plausible downside version of those same risks to test whether the quote still protects known cost without treating contingency as profit.

Project base cost minimum

baseCostExTax ≥ 0 currency units/project before contingency, ex tax — A lower value is rejected before calculation.

Project base cost maximum

baseCostExTax ≤ 10,000,000 currency units/project before contingency, ex tax — A higher value is rejected before calculation.

Risk 1 probability minimum

riskOneProbability ≥ 0 decimal probability of risk 1 occurring — A lower value is rejected before calculation.

Risk 1 probability maximum

riskOneProbability ≤ 1 decimal probability of risk 1 occurring — A higher value is rejected before calculation.

Risk 1 cost impact minimum

riskOneImpactExTax ≥ 0 currency units/project if risk 1 occurs, ex tax — A lower value is rejected before calculation.

Risk 1 cost impact maximum

riskOneImpactExTax ≤ 10,000,000 currency units/project if risk 1 occurs, ex tax — A higher value is rejected before calculation.

Risk 2 probability minimum

riskTwoProbability ≥ 0 decimal probability of risk 2 occurring — A lower value is rejected before calculation.

Risk 2 probability maximum

riskTwoProbability ≤ 1 decimal probability of risk 2 occurring — A higher value is rejected before calculation.

Risk 2 cost impact minimum

riskTwoImpactExTax ≥ 0 currency units/project if risk 2 occurs, ex tax — A lower value is rejected before calculation.

Risk 2 cost impact maximum

riskTwoImpactExTax ≤ 10,000,000 currency units/project if risk 2 occurs, ex tax — A higher value is rejected before calculation.

Minimum contingency rate minimum

minimumContingencyRate ≥ 0 decimal fraction of project base cost — A lower value is rejected before calculation.

Minimum contingency rate maximum

minimumContingencyRate ≤ 1 decimal fraction of project base cost — A higher value is rejected before calculation.

• All hours, utilisation, costs, rates and recovery targets are supplied by the user.
• Money values use one consistent ex-tax basis.
• No provider fee, jurisdiction, benchmark or demand forecast is embedded.
• Raw engine precision is retained until display.
• Low, base and high are user-authored scenarios, not supplied contingency percentages or probability benchmarks; every row uses the same registered engine rule.

This planner has no current policy-data dependency. Its commercial assumptions are user supplied. Registered family-level regression suites exercise the shared business-logic engine and worked-result reconciliation.

• Results depend on the completeness and classification of the entered business records.
• The planner does not forecast demand, utilisation, supplier terms or project outcomes.
• This is educational business decision support rather than accounting, tax, legal or financial advice.
• Probabilities and impacts are user scenarios, not forecasts; use the two visible rows for the two risks most relevant to this decision.
• Contingency is an uncertainty allowance, not profit and not a substitute for known project costs.

This is educational decision support, not tax, accounting, legal or financial advice. Check the treatment of your actual transactions under the rules that apply to your business and seek qualified advice where appropriate.

Registered family-level suites test formula invariants and example reconciliation; the release ledger records that coverage without claiming a separate oracle for every line of public copy. There is no official threshold or benchmark to refresh for this planner. Commercial inputs remain user-supplied because they vary by business and contract.

1. 2026-07-16: Initial public release of the Project Contingency planner and methodology.