Automatic Decomposition of Safety Integrity Levels: Optimization by Tabu Search

Abstract

Abstract. Automotive Safety Integrity Levels (ASILs) are used by ISO 26262, the new automotive functional safety standard, to categorize the stringency of safety requirements. In the course of a hierarchical system design, ASILs are iteratively allocated to subsystems and components. This ASIL decomposition allows for redundant elements to share the responsibility of meeting a given ASIL and finding efficient decomposition solutions has a significant, positive, impact on development costs. This paper describes a novel technique that uses Tabu Search to explore the solution space efficiently. We have applied the technique to a case study of a hybrid braking system.