A case study in the integration of accident reports and constructivedesign documents

Accident reports are intended to explain the causes of system failures. They are based upon the evidence of many different teams of experts and are, typically, the result of a lengthy investigation process. They are important documents from a software engineering perspective because they guide the intervention of regulatory authorities that must reduce the impact and frequency of system failures. There are, however, a number of problems with current practice. For example, the Rand report recently highlighted the lack of techniques that can investigate the role of software failure in major incidents. Similarly, there are no established techniques, which help to insure that these failures are used to inform subsequent design. This paper, therefore, shows how a number of relatively simple graphical notations can be used to improve the next generation of accident reports.