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 (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. 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

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!