Exploring the Impact of Different Cost Heuristics in the Allocation of Safety Integrity Levels

• Type: Article in International Conference Proceedings Book
• Date: 2014

Authors

Azevedo, LS (Author) Other; Parker, D (Author) Other; Papadopoulos, Y (Author) Other; Walker, M (Author) Other; Sorokos, I (Author) Other; Rui Esteves Araújo (Author) FEUP

Conference proceedings International

Title: MODEL-BASED SAFETY AND ASSESSMENT, IMBSA 2014

Pages: 70-81

4th International Symposium on Model-Based Safety and Assessment (IMBSA)

Munich, GERMANY, OCT 27-29, 2014

Indexing

ISI Web of Knowledge - 3 Citations

Scopus - 6 Citations

Other information

Authenticus ID: P-00G-1N5

Abstract (EN): Contemporary safety standards prescribe processes in which system safety requirements, captured early and expressed in the form of Safety Integrity Levels (SILs), are iteratively allocated to architectural elements. Different SILs reflect different requirements stringencies and consequently different development costs. Therefore, the allocation of safety requirements is not a simple problem of applying an allocation "algebra" as treated by most standards; it is a complex optimisation problem, one of finding a strategy that minimises cost whilst meeting safety requirements. One difficulty is the lack of a commonly agreed heuristic for how costs increase between SILs. In this paper, we define this important problem; then we take the example of an automotive system and using an automated approach show that different cost heuristics lead to different optimal SIL allocations. Without automation it would have been impossible to explore the vast space of allocations and to discuss the subtleties involved in this problem.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 12