How rmForge calculates Risk Level

Five bands (S1 through S5): Negligible, Minor, Serious, Critical, Catastrophic. S5 Catastrophic covers death and permanent severe disability.

Five levels, numbered 1 to 5: Remote (less than 0.01 percent), Unlikely (0.01 to 1 percent), Possible (1 to 10 percent), Probable (10 to 50 percent), and Frequent (more than 50 percent). The same scale is used for P1, the chance the hazardous situation happens, and P2, the chance it then leads to harm. The Scales tab of your workbook shows it.

P1 is the chance that a hazardous situation happens. P2 is the chance that, once the hazardous situation exists, harm actually happens. Each is scored from 1 to 5 on the probability scale shown on the Scales tab of your workbook.

Po is looked up from a deterministic combined-probability table as a function of p1 and p2. The table is identical across analyses. Language-model judgment does not override the table value.

Risk Level is looked up from a fixed table using Severity and Po, the probability that harm occurs. There are four levels: Low, Medium, High, and Unacceptable. The Risk Region tab of your workbook shows the table.

You can edit the row in the downloaded workbook. The workbook will recompute it according to your choices. With all risk analysis, the user must perform a cross functional review and approval process for all changes.

Four levels give each row a clear next step. The Risk Region tab of your workbook defines them. Low: reduce the risk as far as possible and document the rationale. Medium: a risk control is required, with a benefit-risk analysis if the residual risk stays Medium. High: a risk control and a benefit-risk analysis are both required. Unacceptable: reduce the risk to High or below and escalate to management. rmForge proposes at least one Risk Control Measure for every row. In rmForge's opinion, a fifth level adds ambiguity without evidence that it improves safety. This is our opinion, not a claim of fact.

Risk remaining after the application of risk control measures and the potential for those risk control measures to create new risks. ISO 14971 requires that residual risk post risk control measures be evaluated and, if not acceptable, that further controls or a benefit-risk justification be documented.

Your risk management plan sets your criteria for risk acceptability under ISO 14971, the International Organization for Standardization (ISO) standard for medical device risk management. rmForge's default starting point is on the Risk Region tab of your workbook. Low: reduce the risk as far as possible and document the rationale. Medium: a risk control is required, with a benefit-risk analysis if the residual risk stays Medium. High: a risk control and a benefit-risk analysis are both required. Unacceptable: reduce the risk to High or below and escalate to management. There is no setting to change these during an analysis. You can edit the Risk Region tab in your copy of the workbook to match your plan. The Risk Level cells read the table on that tab.

ALARP (As Low As Reasonably Practicable) is driven by the manufacturer. rmForge presents proposed risk levels and the manufacturer ultimately decides risk acceptability. Refer to ISO 14971 for detail.

Not at this time. Custom scales are on the roadmap for enterprise customers. Custom scales must be controlled documents on the customer side; we do not let you change scales mid-analysis.

Use error is a user action, or a missed action, that leads to a different result than the manufacturer intended or the user expected. Abnormal use is a deliberate act, or a deliberate failure to act, that goes against normal use. rmForge tags each row as Intended Use, Misuse: Use Error, or Misuse: Abnormal Use. It includes abnormal use rows when they are reasonably foreseeable.

Yes, in part. rmForge's Information and Security hazard category covers data and cybersecurity hazards. It runs when your wizard answers say the device has software or connects to a network. Full cybersecurity threat modeling under U.S. Food and Drug Administration (FDA) premarket cybersecurity guidance is on the roadmap.

Per IEC 60601-1 and rmForge's N versus F separation, fault rows assume single-fault conditions only. Cascading faults are not enumerated as single rows; they require a separate analysis. However, a foreseeable sequence of events is indicative of an event leading to a hazardous situation that may lead to harm of patient or property.