A case study using SAM-safety analysis of PES

The safety argument manager, SAM, is a tool to support the process of developing safety cases (Fodder, J. et al., see Proc. Safety-Critical Systems Symposium, Bristol, 1993). In SAM a safety case is expressed by a goal structure and associated solutions. Each solution is expressed in Toulmin argument form (1984). Fault trees can be constructed and attached to a goal. We have constructed the tool SAM, and investigated how these three different notations can be used in developing a real safety case for a complex system by completing a safety case study. This paper presents the case study, using SAM, of the PES (Programmable Electronic Systems) example (PES-programmable electronic systems in safety related applications, Health and Safety Executive, p.80-99, 1987)