The HEAT/ACT Preliminary Safety Case: A case study in the use of Goal Structuring Notation

The HEAT/ACT project consists of replacing the conventional mechanical flight control system of a helicopter with a fly-by-wire system. With such a project, the safety concerns are obvious, and therefore the development of a thorough and convincing Safety Case is paramount. The project therefore chose to adopt a phased approach to safety case development, beginning with a Preliminary Safety Case (PSC). Goal Structuring Notation (GSN) was chosen as the development method for the PSC, because of its perceived merits of ease of construction and clarity of review. This work was first reported in a presentation at the UK Safety Critical Systems Symposium (SSS'04), which described the initial development of the PSC argument structure, and investigated some of the practical issues identified in using GSN. This paper revisits the HEAT/ACT project. It reprises the original construction of the GSN argument, and goes on to show how the PSC has developed and evolved since that initial develo...

• Type: Conference
• Year: 2004
• Where: SCS
• Authors: Paul Chinneck, David Pumfrey, John McDermid
• Keywords: Conventional Mechanical Flight, HEAT/ACT Project, Safety Case, SCS 2004, Software Engineering