Formula Used
Exposure A = (Probability A / 100) × (Impact A × 10)
Exposure B = (Probability B / 100) × (Impact B × 10)
Interaction Multiplier = 1 + (Correlation / 100)
Criticality Multiplier = 1 + (Criticality / 5)
Detectability Multiplier = 0.5 + (Detectability / 10)
Raw Pair Score = (Exposure A + Exposure B) × Interaction Multiplier × Criticality Multiplier × Detectability Multiplier
Residual Pair Score = Raw Pair Score × (1 − Mitigation / 100)
Priority Index = Residual Pair Score × (1 + Criticality / 10)
This structure helps project managers compare linked threats, see mitigation value, and rank actions using one repeatable portfolio method.
How to Use This Calculator
- Add one card for each important project risk pair.
- Enter probabilities for both connected risks.
- Score impacts from 0 to 10 using your project scale.
- Set correlation higher when two risks amplify each other.
- Use criticality to reflect milestone or deliverable importance.
- Set detectability difficulty higher for hidden or late signals.
- Enter mitigation strength to represent current controls.
- Submit the form and review the chart, table, and portfolio summary.
Example Data Table
| Pair Label | Prob A | Impact A | Prob B | Impact B | Correlation | Criticality | Detectability | Mitigation |
|---|---|---|---|---|---|---|---|---|
| Schedule Slip vs Vendor Delay | 45% | 8 | 35% | 7 | 40% | 4 | 4 | 20% |
| Scope Change vs Resource Gap | 55% | 9 | 40% | 8 | 60% | 5 | 5 | 15% |
| Testing Defect vs Integration Failure | 30% | 7 | 25% | 9 | 50% | 4 | 3 | 10% |
FAQs
1. What does this calculator measure?
It estimates the combined effect of two connected project risks. The tool shows raw exposure, residual exposure, and priority after mitigation.
2. Why use risk pairs instead of single risks?
Many project issues reinforce each other. Pair analysis highlights compounding threats that single-risk scoring can miss during planning and review.
3. How should I choose correlation values?
Use low values when risks rarely interact. Use higher values when one issue increases the probability, impact, or timing pressure of the other.
4. What does criticality represent?
Criticality shows how important the affected deliverable or milestone is. High-criticality pairs deserve faster response even when probabilities are similar.
5. What is detectability difficulty?
It reflects how hard early warning signs are to notice. Harder-to-detect pairs receive more weight because response time is shorter.
6. How does mitigation strength change the score?
Mitigation reduces the raw pair score into a residual score. Stronger controls lower residual exposure and improve portfolio efficiency.
7. Can I use this for vendor, scope, and resource risks?
Yes. The method works for schedule, cost, quality, procurement, staffing, change, and dependency risks across most project environments.
8. What do the CSV and PDF exports include?
They include the pair names and calculated outputs. This helps with stakeholder reviews, audit trails, and reporting packs.