Safety Classifications (ASIL & DAL)

NirmIQ supports industry-standard safety classifications for requirements, enabling compliance with automotive (ISO 26262) and aerospace (DO-178C) standards.

Overview

Safety classifications help teams:

• Prioritize requirements based on safety criticality
• Trace safety requirements through the development lifecycle
• Demonstrate compliance with industry regulations
• Focus testing and verification efforts appropriately

ASIL - Automotive Safety Integrity Level

Standard: ISO 26262 (Functional Safety for Road Vehicles)

Level	Description	Example Use Case
QM	Quality Management	Non-safety related functions
A	Lowest safety integrity	Comfort features with minor safety impact
B	Low-medium integrity	Features affecting vehicle handling
C	Medium-high integrity	Brake assist systems
D	Highest integrity	Autonomous emergency braking, airbags

ASIL Color Coding

In NirmIQ, ASIL levels are color-coded for quick identification:

• ASIL-D: Red (most critical)
• ASIL-C: Orange
• ASIL-B: Yellow
• ASIL-A: Green
• QM: Gray

DAL - Design Assurance Level

Standard: DO-178C (Software Considerations in Airborne Systems)

Level	Effect	Verification Rigor
A	Catastrophic	Most stringent
B	Hazardous	Very high
C	Major	High
D	Minor	Moderate
E	No Effect	Lowest

DAL Color Coding

• DAL-A: Red (catastrophic failure risk)
• DAL-B: Orange
• DAL-C: Yellow
• DAL-D: Green
• DAL-E: Gray

Setting Safety Classifications

On Individual Requirements

1. Open a requirement for editing
2. Find the Safety Classification section
3. Select the appropriate ASIL or DAL level
4. Save the requirement

Bulk Classification

1. Select multiple requirements in the table
2. Use Bulk Edit from the toolbar
3. Set the safety classification
4. Apply changes

Filtering by Safety Level

Use the filter controls to view requirements by safety level:

1. Click the Filter button in the requirements table
2. Select ASIL Level or DAL Level
3. Choose the levels to display

This is useful for:

• Safety reviews focusing on high-criticality items
• Generating compliance reports
• Planning verification activities

Best Practices

1. Classify Early

Assign safety classifications during requirements creation, not after development.

2. Inherit Appropriately

Child requirements typically inherit or exceed the parent's safety level.

3. Document Rationale

Use the change log to document why a specific level was assigned.

4. Review Periodically

Safety classifications may need updating as system understanding evolves.

Integration with FMEA

Safety classifications integrate with FMEA analysis:

• High ASIL/DAL requirements should have corresponding failure modes analyzed
• RPN calculations can be weighted by safety classification
• Traceability reports show coverage of safety-critical requirements

Compliance Reporting

Generate safety classification reports for audits:

1. Go to Analytics → Compliance Reports
2. Select Safety Classification Summary
3. Choose project scope
4. Export as PDF or Excel

The report includes:

• Distribution of requirements by safety level
• Coverage metrics
• Gap analysis for missing classifications