System Safety's Role in Requirements Analysis

1. System Safety's Role in Requirements Analysis Exploring Concurrent Systems Engineering & System Safety Engineering Activities in Early Program Development

2. System Engineering mission: DODI 5000.2 (paraphrased) • Translate an operational need into a configured system • Integrate all technical disciplines in a coordinated effort that meets cost schedule and performance • Ensure compatibility of interfaces • Ensure design meets requirements • Measure and control technical risk

3. System Safety Mission: Mil-Std- 882 (paraphrased) • Optimize safety, within cost and operational effectiveness, at a system level (System Safety Program) • Influence the translation of operational needs into a configured system with appropriate safety characteristics (PHL, Safety Design Guidelines, PHA, SSHA, OSHA, etc) • Influence all technical disciplines in a coordinated effort to ensure that safe design practices are uniformly applied and identified hazards are controlled (Safety Design Guidelines, Hazard Mitigation and Tracking) • Ensure compatibility of interfaces where interfaces effect the safety of the system (PHL, PHA, SSHA, OSHA, etc) • Ensure design meets requirements where requirements are safety driven (V&V of Safety Design Guidelines, Hazard Mitigation and Tracking) • Measure and control safety risk (see above)

4. Prepare System Spec Prepare System Spec Requirements Flow Down To Segments Requirements Flow Down To Segments Operational Concept Operational Concept Mission Needs Statement Mission Needs Statement Key System Requirements Key System Requirements Sizing/ Sensitivity Analysis Sizing/ Sensitivity Analysis Mission Analysis Mission Analysis System Trades System Trades System Concept System Concept Define Variable System Configuration (s) Define Variable System Configuration (s) Perform Segment/ Subsystem Trades Perform Segment/ Subsystem Trades Select Baseline Configuration Select Baseline Configuration Establish Cost & Risk Establish Cost & Risk Verify Capability Verify Capability Parallel Missions... Parallel Timelines... Preliminary Hazards Analysis System Level Safety Req Development Concept Trade Safety Considerations System Level Requirements Analysis System Level Design Guidelnes Development System Safety Requirements Flowdown Regulatory Requirements Identification Preliminary Hazards Lists

5. Understanding Unifies Process • Explore the integration of parallel activities into concurrent activities • Minimize “over the wall” activities • Involve System Safety in Systems Processes • Involve Systems Engineering in System Safety Processes

6. Good Requirements • Singular in scope • Shall • State specific need or objective • Be verifiable or measurable Sample Safety Requirements: ... shall conduct a preliminary systems safety and hazards analysis and prepare a preliminary systems safety hazard list. ...Design shall comply with OSHA... System Safety Requirements are notoriously poorly developed and rarely relate to the product

7. Early System Safety Involvement is crucial • Early involvement of system safety engineers is crucial to: • Improving Trade Off studies and analyses • Reducing poorly defined safety requirements • Properly evolving general and regulatory requirements to good workable requirements • Properly allocating safety requirements for flow down • improving safety design guidelines System Safety Engineers Are valuable assets to early development and are underutilized in this phase

8. Working together works better • As system engineers understand more about system safety and system safety engineers understand more about system engineering the “over the wall” evolves into concurrent engineering.

9. Better understanding through participation • Personal, professional and organizational involvement to improve work products • Chapter cross training/ joint meetings • Personal networking Enjoy!