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Overview

In TestAuto2 — Automotive Safety Solution, Harm Severity applies primarily to medical device and healthcare-related safety modules where ISO 14971 risk management principles govern product safety analysis. Unlike ISO 26262 automotive functional safety (which uses Severity S0-S3 to rate injury outcomes), Harm Severity specifically addresses medical device harm categories defined by ISO 14971:2019. The Harm Severity scale progresses from negligible inconvenience through catastrophic patient death, enabling proportionate risk control measures aligned with the clinical impact of potential failures.

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Key Characteristics

CharacteristicValue
Scale Range1–5 levels
ApplicationISO 14971 medical device risk analysis
UsageRisk matrices, Risksheet cell styling, control prioritization
Default ValueLevel 4 (Critical)
Color SchemeGray → Green → Black → Red (progressive risk)

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Harm Severity Levels

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Level 1: Negligible

Description: Inconvenience or temporary discomfort without medical intervention required.
PropertyDetails
Clinical ImpactNo injury; temporary discomfort only
Medical InterventionNone required
DurationTemporary; resolves without treatment
ExamplesMinor skin irritation, temporary numbness, slight inconvenience
Color CodeGray (#95A5A6)
Iconℹ️ (trivial)
Sort Order0
Regulatory DriverMinimal risk control measures
When to Use:
Assign Level 1 only when the hazardous situation results in inconvenience without any medical intervention threshold being crossed. This is the lowest harm category and represents acceptable risk levels in most contexts.

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Level 2: Minor

Description: Temporary injury or impairment requiring professional medical intervention.
PropertyDetails
Clinical ImpactTemporary injury requiring medical care
Medical InterventionProfessional intervention needed (e.g., wound care, minor suturing)
DurationTemporary; resolves with treatment
ExamplesMinor cuts requiring sutures, temporary bruising, mild allergic reaction
Color CodeGray (#95A5A6)
Icon(minor)
Sort Order1
Regulatory DriverStandard risk control measures
Boundary Definition:
Minor severity begins where professional medical intervention becomes necessary. This distinguishes it from Negligible (self-care only) and separates it from Serious harm by the extent and duration of medical care required.

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Level 3: Serious

Description: Injury or impairment requiring professional medical intervention with extended recovery or ongoing management.
PropertyDetails
Clinical ImpactSerious injury with lasting effects or extended care
Medical InterventionSignificant professional intervention; may require hospitalization
DurationExtended recovery period; ongoing management possible
ExamplesBroken bones, significant lacerations, temporary vision loss, hospitalization
Color CodeGreen (#2ECC71)
Icon⚠️ (major)
Sort Order2
Regulatory DriverEnhanced risk control measures required
Clinical Distinction:
Serious severity represents injuries beyond what typical urgent care can address, often requiring specialist intervention, imaging studies, or inpatient treatment. Extended recovery periods or functional limitations characterize this level.

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Level 4: Critical

Description: Permanent impairment or life-threatening injury.
PropertyDetails
Clinical ImpactPermanent disability or immediate life threat
Medical InterventionEmergency intervention required; ICU/specialized care possible
DurationPermanent impairment; life-long consequences
ExamplesPermanent loss of limb/vision, spinal cord injury, severe organ damage, cardiac arrest
Color CodeBlack (#000000)
Icon(major)
Sort Order3
Regulatory DriverDEFAULT — Stringent risk control; conservative assumption
Use CaseDefault selection for unrated harms; escalates to higher controls
Why Default?
Level 4 (Critical) is pre-selected as the default harm severity classification to enforce conservative risk management. This ensures that uncompleted assessments default to higher control requirements rather than underestimating harm potential. Analysts must actively downgrade to lower severity levels only after documented justification.

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Level 5: Catastrophic

Description: Highest severity level indicating patient death.
PropertyDetails
Clinical ImpactFatality; loss of life
Medical InterventionUnsurvivable condition
DurationIrreversible; permanent loss of life
ExamplesAnaphylactic shock, massive hemorrhage, complete system failure
Color CodeRed (#E74C3C)
Icon(blocker)
Sort Order4
Regulatory DriverMaximum risk control rigor; potential market withdrawal
Regulatory Implications:
Catastrophic harm classifications trigger the most stringent requirements under ISO 14971:2019:
  • Mandatory risk control implementation
  • Multiple independent controls often required
  • Enhanced verification and validation activities
  • Potential for product market withdrawal if residual risk remains unacceptable
  • Mandatory benefit-risk analysis documentation

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Harm Severity Scale Reference Table

LevelSeverityMedical DescriptionColorIcon
1NegligibleMinor discomfort, no medical attention#eaf5e9 (Green)$ok-sign
2MinorReversible injury, outpatient treatment#fff3d2 (Yellow)$info-sign
3ModerateSignificant injury, hospitalization#f8eae7 (Orange)$warning-sign
4SeriousSevere/irreversible injury#f8eae7 (Red)$remove-sign
5CatastrophicLife-threatening or fatal#f8eae7 (Dark Red)$fire

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Integration with Risk Analysis

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Risk Matrix Positioning

Harm Severity combines with Risk Probability to populate risk evaluation matrices in ISO 14971 Risk Control Plans: 
Risk Level = f(Harm Severity, Risk Probability)

Where:
  Risk Probability = P1 (Hazardous Situation) × P2 (Harm Given Situation)
  Risk Level ∈ {Acceptable, ALARP, Unacceptable, Special Consideration}
Harm Severity establishes the row dimension of risk matrices in Risksheet configurations. Probability forms the column dimension. Their intersection determines the initial risk level and the stringency of required risk controls.

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Risksheet Configuration

In Risksheet configurations for ISO 14971 Risk Control Plan modules, Harm Severity:
  • Data Type: Enum field bound to harmSeverity custom field
  • Column Width: Typically 80–100px in Risksheet layouts
  • Cell Styling: Applied via riskStyle() decorator function referencing severity and probability values
  • Sort Order: Used for report ordering (1 = lowest, 5 = highest)
  • Filtering: Enables querying by harm level (e.g., “Show all ASIL C/D hazards”)

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Pre-Control and Post-Control Evaluation

Harm Severity participates in two-stage risk assessment:
StageContextSeverity Handling
Initial Risk (Pre-Control)Before mitigationSeverity value from hazard analysis
Residual Risk (Post-Control)After risk controls appliedSeverity typically unchanged; probability reduced
Benefit-Risk DecisionIf residual risk unacceptableSeverity documented; additional controls or market withdrawal considered
In medical device risk analysis, implementing a risk control typically reduces Probability, not Severity. A control cannot reduce the harm a hazard could cause—only reduce the likelihood it occurs. Severity remains fixed throughout the product lifecycle unless fundamental design changes occur.

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Comparison: Harm Severity vs. HARA Severity

TestAuto2 includes both enumerations for different safety domains:
AspectHarm Severity (ISO 14971)HARA Severity (ISO 26262)
DomainMedical device/healthcareAutomotive functional safety
Scale1–5 levelsS0–S3 (4 levels)
FocusPatient/occupant injury outcomeVehicle occupant/other road user injury
Risk ContextMedical device hazardous situationsAutomotive hazardous events
UsageISO 14971 risk matricesISO 26262 ASIL determination
Related EnumerationsRisk ProbabilityHARA Exposure, HARA Controllability
Use Harm Severity exclusively in ISO 14971 healthcare/medical device modules. Use HARA Severity in ISO 26262 automotive functional safety analysis.

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Color-Coded Severity Visualization

Harm Severity colors are used consistently across Risksheet views, reports, and dashboards:
Severity LevelDisplay ColorBackgroundText ColorCSS Class
Negligible (1)Green#eaf5e9#1d5f20severity-negligible
Minor (2)Yellow#fff3d2#735602severity-minor
Moderate (3)Orange#f8eae7#ab1c00severity-moderate
Serious (4)Red#f8eae7#ab1c00severity-serious
Catastrophic (5)Dark Red#f8eae7#ab1c00severity-catastrophic
Accessibility Note: Color alone is insufficient for determining severity. Always pair color with explicit severity labels or numeric indicators in reports and UI elements for users with color vision deficiency.

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Usage in Work Item Types

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Harm Work Item Type

The Harm work item type captures individual harm outcomes within an ISO 14971 analysis. The harmSeverity custom field stores the enumeration value: 
Work Item Type: Harm
Field: harmSeverity (Enum)
Allowed Values: 1 | 2 | 3 | 4 | 5
Linked to: Hazard (risk analysis structure)
            Risk Control (mitigation traceability)

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Risk Control Plan Integration

In ISO 14971 Risk Control Plan Risksheet configurations, Harm Severity feeds into benefit-risk analysis:
  • Initial Risk Calculation: RiskLevel_Initial = f(HarmSeverity, P1 × P2)
  • Control Prioritization: Higher severity harms trigger expedited control implementation
  • Residual Acceptance: Catastrophic harms require executive review and benefit-risk justification

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Frequently Asked Questions

Q: Can Harm Severity be downgraded after initial assessment?
A: Yes, but only through documented risk reassessment. Changes require traceability to updated hazard analysis, new clinical data, or design changes. Downgrades must be approved per your organization’s change control process. Q: What is the difference between Serious (Level 3) and Critical (Level 4)?
A: Serious represents extended injury requiring specialist care but with recovery or functional management possible. Critical indicates permanent impairment or immediate life threat—irreversible consequences that dominate risk management decisions. Q: Why is Critical the default?
A: Conservative risk management assumes worst-case outcomes until evidence proves otherwise. Defaulting to Critical prevents accidental underestimation of harm and ensures uncompleted assessments receive appropriate control investment. Q: How does Harm Severity relate to regulatory compliance timelines?
A: ISO 14971:2019 mandates risk evaluation before marketing. Catastrophic and Critical harms often extend timelines due to enhanced verification, control validation, and potential design iterations. Plan your project schedule accordingly.

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References and Standards

  • ISO 14971:2019 — Medical devices—Application of risk management to medical devices
    • Section 7.4: Harm and Risk Estimation
    • Annex B: Severity and Probability Tables
  • IEC 62304 — Medical device software lifecycle processes (complements ISO 14971)
  • FDA Guidance — Medical Device Risk Analysis (references ISO 14971 framework)
For automotive functional safety domains, see HARA Severity and Safety Goal Derivation.