Multiobjective Optimization of the Performance of Safety Systems

Abstract

The activation of the safety-instrumented systems in industrial processes is carried out after the occurrence of specific deviations (dangerous situations) from normal operation (normal situations), but in some cases, the safety-instrumented systems are activated in the absence of deviations or requests; these are the unwanted activations. The system chosen in this study is a system with high-pressure gas and inflammable gas, and it is protected by a firefighting system that prevents any kind of accident in order to protect humans, systems, and the environment. The activation of the emergency shutdown system causes stoppage of the whole system by closing the input and output valves. This paper presents the optimization of the voting redundancies of safety-instrumented systems by a multiobjective genetic algorithm. The objectives to optimize are the average probability of dangerous failure on demand, which represents the system safety integrity, and the spurious trip rate, which presents the activation of a safety function without the presence of a demand.

Keywords

• optimize
• vote
• redundancy
• safety instrumented system
• emergency shutdown system
• genetic algorithm