System Safety Concepts

1. System Safety Concepts Dave Balderston Office of System Safety March 26, 2003

2. Outline • Introduction • References • System Concepts • Safety Risk Management Concepts • Implementation Issues

3. References • FAA Order 8040.4, “Safety Risk Management” • Draft System Safety Handbook especially Chapter 15, Operational Risk Management located at www.asy.faa.gov (Safety Risk Management)

4. Introduction • System safety approach provides a comprehensive and disciplined, but flexible methodology for identifying and addressing safety concerns • Use system perspective to understand complete situation • Address safety concerns using system concepts • Simple, common sense approach—do it all the time; a formalized approach can help do it better.

5. Basic Questions • What is going on? • Design analysis or system monitoring • What should we worry about? • Hazard identification • How much should we worry? • Risk assessment • What should we do? • Risk management

6. Definition of System • Composite of people, procedures, materials, tools, equipment, facilities, and software • Operating in a specific environment • To perform a specific task or achieve a specific purpose, support or mission requirement • Such as the provision of crash/fire rescue services

7. Major Components of Systemfor Landing Aircraft • Airport Infrastructure • Air Traffic Control Functions • Aircraft and Crew • Environmental Factors • How do these system components need to interact to assure that aircraft land safely?

8. Safety Management Concepts • Safety Goal: Avoid safety losses (death or injury) • Strategy: Manage safety risk (likelihood and severity of potential losses) • Implementation: Identify and control hazards (conditions that lead to increased safety risk)

9. Safety Risk Management Strategy • Design Analysis/System Monitoring • What is going on? • Hazard Identification • What should we worry about? • Risk Assessment • How much should we worry? • Risk Management • What should we do about it?

10. Safety Assurance Steps • Designing in safety assurance (must be done in system development) • Maintaining and strengthening safety assurance (Infrastructure support—procedures, training, maintenance, etc.) • “Real Time” safety assurance (Operations)

11. Safety Order of Precedence • Reduce risk through design (strongest) • Incorporate safety devices • Provide warning devices • Develop procedures and training (weakest—the “human factors” issue)

12. Implementation Issues • Understand the problem in system terms • Appropriate definition of system • Effective system monitoring (inadequate system monitoring can be a hazard) • Involvement of all key stakeholders • Disciplined risk management process, even if expert judgment is the best available evidence • Hazard identification and prioritization • Risk assessment • Risk management

13. Example: Land and Hold Short Operations Risk Assessment • Joint FAA/Industry Team • Identified hazards, assessed risks • Used expert judgment • Report located at www.asy.faa.gov under Safety Risk Management heading

14. Conclusion • System Perspective • Safety Risk Management Process • Implementation Issues