Risk Assessment Calculator
Score and prioritize project risks by combining probability with cost, schedule, and quality impact dimensions. Use it during risk identification workshops to rank threats and decide where mitigation effort is most justified.
About this calculator
Traditional risk scoring multiplies probability by a single impact score (Risk = P × I). This calculator extends that model to capture three impact dimensions simultaneously: cost, schedule, and quality. The formula is: Risk Score = probability × max(costImpact, scheduleImpact, qualityImpact) × (1 + (sumOfAllImpacts − maxImpact) / 10). The dominant impact dimension (the maximum) anchors the score so that a catastrophic cost overrun drives the result. The second term adds a weighted penalty for compound risks — threats that score high across multiple dimensions. This prevents a risk that is moderately bad on all three axes from being scored lower than a risk that is severe on only one axis. All impact values are typically scored on a 1–10 scale.
How to use
A risk has probability = 0.7, cost impact = 8, schedule impact = 6, quality impact = 5. Step 1 — max impact: max(8, 6, 5) = 8. Step 2 — sum of impacts: 8 + 6 + 5 = 19. Step 3 — compound factor: (19 − 8) / 10 = 1.1, so multiplier = 1 + 1.1 = 2.1. Step 4 — risk score: 0.7 × 8 × 2.1 = 11.76. Compare this score against other identified risks to prioritize your response plan. Higher scores warrant immediate mitigation action.
Frequently asked questions
What is the difference between a risk probability-impact matrix and a numeric risk score?
A probability-impact (P×I) matrix categorizes risks into red/amber/green zones using qualitative thresholds, making it easy to communicate to non-technical stakeholders. A numeric risk score provides finer granularity, enabling ranking and comparison across many risks. The matrix is faster to use in workshops but can obscure differences between risks that fall in the same colour band. Numeric scoring, as used in this calculator, supports quantitative risk analysis and integrates with Monte Carlo simulation tools.
How should I set impact scores for cost, schedule, and quality dimensions?
Define your scoring scale before the risk workshop so that all participants use the same reference. A common approach ties each score to a concrete threshold: for cost impact, a score of 5 might mean a 10–20% budget overrun, while a 9 means more than 50% overrun. Schedule impact scores can map to days or weeks of delay relative to the critical path. Quality impact scores can reference defect rates or compliance failures. Written definitions reduce anchoring bias and make scores comparable across different risk owners.
When should a high risk score trigger immediate mitigation versus acceptance?
The decision depends on both the score and your organization's risk appetite. High-probability, high-impact risks (scores in the top quartile of your register) typically warrant active mitigation — changing the project plan to reduce probability or impact. Medium-scored risks may be monitored with a contingency plan ready. Very low-scored risks are often accepted, meaning you acknowledge them but take no proactive action. Always revisit accepted risks at each project gate, since probability and impact can change as the project evolves.