System safety principles

Lessons can be learned from the successes attained by system safety practitioners. System safety is hazards-based and design-based. So is the entirety of the practice of safety. This chapter establishes why it is important for generalist safety professionals to acquire knowledge of system safety principles, and it outlines the system safety idea. As opportunities arise for generalist safety professionals to participate in the design processes, the need for system safety skills will be apparent. 

ABSTRACT In older to design complex safety relevant systems, safety principles are of great use to save time and keep the safety architecture simple. An outline of safety principles has been given by one of the authors in an earlier paper on ESREL 2008. In this paper, the authors will show how the principles have been applied to the Phileas guidance system. 

In this paper we have shown how safety principles cane be efficiently applied to design a safe system. Safety principles allow to bypass a trial and error phase in development. They allow to design a safe architecture in a straightforward manner. 

System safety may grow as a separate discipline or the system safety effort may be absorbed into the mainstream of industrial safety, loss prevention, risk management, loss control, or some other program. A new name or buzzword may appear. Nevertheless, the need for first-time safe systems and for the application of system safety principles, tools, and techniques to systematically identify, analyze, and control hazards as early in the life cycle as possible (with continuing efforts throughout the life cycle) will continue to grow indefinitely. 

Grose applied system safety principles and techniques in preparing hazard control information for management decisions. His process creates a simplified decision chart, the Hazard Totem Pole (Figure 36-7). 

Risk Management The process, derived through the application of system safety principles, whereby management decisions are made concerning control and minimization of hazards and acceptance of residual risks (SSDC-11). 

For an assessment of how system safety principles are becoming a larger part of the practice of safety generalists and for a self-assessment of their current knowledge and skill in relation to the transitions in progress, readers are asked to compare the content of this book and... 

Of course, in mai indnstries, like aerial agriculture, commercial pressures and maiket realities make the task difficnlt. The economics of success can be a difficult balance in cash strapped operations. However, diligent application of system safety principles is even more important when there is pressure on the business, when operations are most vulnerable. It seems that this is particularly tme of aerial agriculture when the vagaries of seasonal work, the ups and downs of primary industry and the continual economic pressure are considered. 

FIG. 13. Objective tree for Level 2 of defence in depth (RCS, reactor coolant system). Safety principle (138) radiological impact on the public and the local environment. 

Integrate systems safety principles in the design and development of products. 

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