Case-Based Reasoning for the Evaluation of Safety Critical Software. Application to The Safety of Railway Transport.

International audienceThe purpose of the work described in this paper is to improve the assessment of the safety analyses for railway transport systems in France. The modes of reasoning which are used in the context of safety analysis and the very nature of knowledge about safety mean that a conventional computing solution is unsuitable and the utilization of artificial intelligence techniques would seem to be more appropriate. The approach which was adopted in order to design and implement an assistance tool for safety analysis involved the following two main activities:– Extracting, formalizing and storing hazardous situations to produce a library of standard cases which covers the entire problem. This process entailed the use of knowledge acquisition techniques;– Exploiting the stored historical knowledge in order to develop safety analysis know-how which can assist experts to judge the thoroughness of the manufacturer’s suggested safety analysis. This second activity involves the use of machine learning techniques in particular the use of Case-Based Reasoning.This paper presents a mock-up of a tool for storing and assessing Software Error Effect Analysis (SEEA) for the safety of automatic devices of terrestrial guided transport system. The purpose of our work is to exploit historical SEEA, which have already been carried out on approved safety-critical software, in order to assess SEEA of new softwar