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

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

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)

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

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

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

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

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.

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