Define & Compare Flowcharts of Each Method Tom Delong

3 » ANSI Process » MIL-STD-882 Process » Safety Cases » SAE ARP 4761 Process » Reports Overview of Methods

4 ANSI Process Residual Risk Review & Acceptance Assess Mishap Risk Understanding Risk Options Identify Mitigation Measures Reduce Risk to Acceptable Level Verify Risk Reduction Iterative Risk Reduction Changes Understanding Risk Drivers Risk Assessment Risk Reduction Understanding Hazards Recognize & Document Hazards Tasks Schedule Team Tools Document the System Safety Approach Program Initiation Hazard Identification Risk Acceptance Hazard Tracking Continuous T Maturing Design Life Cycle Monitoring

5 ANSI Process

6 MIL-STD-882 Process Element 1: Document the System Safety Approach Element 2: Identify and Document Hazards Element 3: Assess and Document Risk Element 4: Identify and Document Risk Mitigation Measures Element 5: Reduce Risk Element 6: Verify, Validate, and Document Risk Reduction Element 7: Accept Risk and Document Element 8: Manage Life-Cycle Risk

7 Safety Cases

8 A Simple Goal Structure

9 SAE ARP 4761 Process Determine Impact of S/W Design Define Initial System Safety Design Requirements SIL Testing Ground Testing Flight Testing Determine severity of failure conditions on the A/C or aircrew Determine S/W Levels A/B/C/D/E Allocate S/W functions to appropriate CSCIs CSCs, CSUs Software Requirements and Definition System Safety Engineering IAW ARP 4761 Software Coding And Unit Testing PDRCDR SOFTWARE DESIGN Analyze System Hazards Refine Hazard Mitigations and Identify Derived Safety Reqmts INTEGRATION TESING/ QUALIFICATION TESTING Determine S/W Safety Involvement Determine S/W Level Define S/W Safety Critical Requirements Determine S/W Safety Hazard Mitigations Define S/W Safety Verification Requirements Ensure Compliance with Safety-Critical Requirements Conduct S/W Safety Analyses Per 1228 DO-178B Software Design Assurance SSPP per “882” PSSA SSA Software Safety IAW IEEE STD 1228 Perform Test Safety Analysis & Develop S-C Test Requirements (FMETs/FTs/CWAs) Integration Specs & SRSs TDOCs FHA

10 Safety Cases

11 » Following are key elements of most standards:  Scope  System Description  System Hazards  Safety Requirements  Risk Assessment  Hazard Control / Risk Reduction Measures  Safety Analysis / Test  Safety Management System  Development Process Justification  Conclusions Typical Safety Case Contents

12 Safety Assessment Report Purpose » Historical record » Comprehensive evaluation of risk  60 days prior to test  60 days prior to fielding  New phase of contract or completion » Sent to DTIC & MANPRINT Database » Provides manufacturer’s statement of risk control with justification Contents » Introduction » System description » System operations » System safety engineering » Conclusions (signed statement) » References