Prerequisites
Before evaluating initial risk, ensure you have:- An open HARA document with identified hazards (see Identify Hazards and Harm Scenarios)
- Use steps, hazards, hazardous situations, and harms linked in the risksheet hierarchy
- Harm severity values assigned in the Standard Harms catalog
Understanding the P1 x P2 Probability Model
ISO 14971 decomposes overall probability into two independent factors:| Factor | Field | Question | Scale |
|---|---|---|---|
| P1 — Hazard Probability | preHazardProbability | How likely is the hazardous situation to occur? | 0-5 (frequency-based) |
| P2 — Harm Probability | preHarmProbability | Given the hazardous situation, how likely is it to cause harm? | 0-5 (percentage-based) |
Step 1: Switch to the Initial Evaluation View
- Open your HARA document in risksheet mode
- Select the Initial Evaluation view from the view switcher — this shows 9 columns focused on pre-mitigation assessment
- Confirm you can see the P1, P2, P (Combined), and Pre-Risk Level columns
Step 2: Assign P1 — Hazard Probability
For each risk record row, select the P1 (Hazard Probability) value from thepreHazardProbability dropdown:
| P1 Value | Label | Frequency | Guidance |
|---|---|---|---|
| 1 | Very unlikely | <= 1/100,000 | Injury would be exceptionally rare |
| 2 | Unlikely | <= 1/10,000 | Injury would be rare |
| 3 | Possible | <= 1/1,000 | Injury could occur occasionally |
| 4 | Likely | <= 1/100 | Injury is expected to occur |
| 5 | Very likely | <= 1/1 | Injury is almost certain |
Step 3: Assign P2 — Harm Probability
For each risk record, select the P2 (Harm Probability) value from thepreHarmProbability dropdown:
| P2 Value | Label | Percentage | Guidance |
|---|---|---|---|
| 1 | Rare | <= 5% | Hazardous situation very rarely leads to harm |
| 2 | Occasional | 6-25% | Some chance the situation produces harm |
| 3 | Probable | 26-75% | More likely than not to produce harm |
| 4 | Frequent | 76-95% | High likelihood of harm |
| 5 | Almost certain | >= 96% | Harm is virtually guaranteed |
Step 4: Review the Combined Probability (P)
The risksheet automatically computes the combined probability P using the P1 x P2 bucketing algorithm:- The system multiplies P1 x P2 (product range: 1-25)
- The product is bucketed into a 1-5 combined probability:
| P1 x P2 Product | Combined P | Meaning |
|---|---|---|
| 1-3 | 1 | Remote probability |
| 4-8 | 2 | Low probability |
| 9-13 | 3 | Moderate probability |
| 14-18 | 4 | High probability |
| 19-25 | 5 | Very high probability |
preControlProbability column updates automatically — no manual entry is needed.
Step 5: Read the Pre-Risk Level
The risksheet looks up the combined probability P and harm Severity in the 5x5 risk matrix and displays the result in the Pre-Risk Level (preRisk) column:
| Risk Level | Color | Meaning | Required Action |
|---|---|---|---|
| Acceptable | Green | Risk is tolerable | Document rationale; no further action required |
| Investigation | Amber | Risk is in the ALARP zone | Further analysis or benefit-risk justification needed per ISO 14971 |
| Unacceptable | Red | Risk exceeds tolerance | Mandatory risk reduction through risk controls |
Risk cells are automatically color-coded: green (
rpn1) for acceptable, amber (rpn2) for investigation, red (rpn3) for unacceptable. Row headers also reflect the final risk status at a glance.Step 6: Document and Iterate
- Review all pre-mitigation risk levels in the Initial Evaluation view
- For any risk rated Unacceptable or Investigation, proceed to Assign Risk Controls to Hazards
- For risks rated Acceptable, document the rationale for acceptance
ISO 14971 requires that initial risk evaluation be performed for each identified hazardous situation. The pre-mitigation assessment establishes the baseline risk profile before any controls are applied.
What Happens Next
After completing the initial risk evaluation:- Unacceptable risks must have risk controls assigned — see Assign Risk Controls to Hazards
- Investigation risks require further analysis or benefit-risk justification — see Perform Benefit-Risk Analysis
- Residual risk is evaluated after controls are in place — see Evaluate Residual Risk
Sources
Sources
HARA risksheet configuration (
HARATemplate/risksheet.json), risk record custom fields (riskRecord-custom-fields.xml), P1 probability scale (pOccurrence-enum.xml), P2 probability scale (p2Occurrence-enum.xml), risk classification (riskRecord-risk-enum.xml), HARA top panel formulas (risksheetTopPanel.vm).