Richard A. Stephans - System Safety for the 21st Century

1. Chapter 2
2. Chapter 3
3. Chapter 10
4. Chapter 12
5. Chapter 15
6. Chapter 21
7. Chapter 22
8. Chapter 24
9. Chapter 25
10. Chapter 26
11. Chapter 27
12. Chapter 28
13. Chapter 30

1. Chapter 2
2. Chapter 3
3. Chapter 5
4. Chapter 7
5. Chapter 8
6. Chapter 9
7. Chapter 10
8. Chapter 11
9. Chapter 12
10. Chapter 13
11. Chapter 14
12. Chapter 15
13. Chapter 16
14. Chapter 17
15. Chapter 18
16. Chapter 19
17. Chapter 20
18. Chapter 21
19. Chapter 23
20. Chapter 24
21. Chapter 25
22. Chapter 28

SECOND EDITION

Richard A. Stephans

Formerly ARES Corporation

Boulder City, USA

I just heard it again. A colleague of mine said that he has always taken the systems view with regard to system safety. I was once again surprised, shocked is probably a better word, that not everyone had that view. It reminded me that there remain varying views of the scope of system safety. The scope of the system safety discipline is broad, just like the industries that use the discipline. The system safety discipline has expanded well beyond the U.S. Department of Defense Community and U.S. borders. As such, its recognized discipline approach and broad scope are becoming better defined.

The International System Safety Society and most system safety professionals take a broad view of the scope of system safety, a system view. It considers the system safety discipline as analyzing all safety aspects for any size system (with a product being just a small system) throughout its entire life cycle. It uses a disciplined systems approach to manage safety risk by tapping into the known knowledge bases and using specific tools and techniques for analysis where knowledge bases do not exist or are insufficient for the technologies used in the system. Known knowledge bases include existing safety codes, safety standards, and lessons learned that have been developed in all technology areas. The system safety professional focuses more attention, however, where there are nonexistent or insufficient knowledge bases from which to draw upon. In this case, the system safety professional uses the specific tools and techniques available in the system safety profession to augment the lack of information in existing knowledge bases. The toplevel analyses identify where new safety requirements are necessary and where existing safety codes and standards can be used. The system safety discipline bridges the gap when existing knowledge bases are lacking and manages safety risks by identifying hazards from the known knowledge bases and the tools and techniques of this profession.

Because the system safety professional focuses more attention where there are no or insufficient knowledge bases, some in the industry perceive that the scope of the system safety discipline is just in those areas where little or no knowledge bases exist. However, the scope of the system safety discipline is much broader, and the system safety professional must have a complete understanding of how to use and apply the existing safety resources, in addition to when to use other system safety analyses to evaluate the entire system throughout its entire life cycle. Some colleagues refer to system safety as the umbrella safety since you must draw upon all safety resources for the technologies involved in the design. The system safety discipline has an established methodology and unique tools for analysis. It establishes acceptable levels of risk as part of the process and does not necessarily seek zero risk or rely only on checklists or standards. It considers rare events and lifecycle operations and analyzes both normal and abnormal circumstances. The discipline manages for success using training, independent assessments, management commitment, and lessons learned, and it plans for failure by establishing emergency response procedures, graceful degradation, surveillance, and maintenance.

This system safety discipline is unique because it addresses the safety of an entire system and its operations using existing knowledge bases and, where knowledge bases are insufficient, the tools of this profession. I am of the opinion that the methodology and tools of the system safety discipline should be applied to every system. I believe every company should develop and implement a system safety program that addresses the hazards in its organization, the products it purchases, and the systems that it designs and operates. Only the degree and depth of the system safety program will vary from system to system. As one colleague stated, I wouldnt spend too much time on the analysis of a paper clip. Using the system safety discipline, I am convinced that a company will apply its resources more effectively and achieve success in its ability to effectively manage safety risks.