Requirements for abnormal conditions and events analysis

The Department of Defence has identified the need to analyze safety systems to eliminate or reduce the associated risk of personnel injury, equipment damage, and environmental damage; Mil-Std-882B, "System Safety Program Requirements" was developed to guide this analysis. The IEEE Computer Society further realized that when software was part of the safety system design software specific additional requirements to Mil-Std-882B were required. The IEEE Computer Society developed IEEE Std 1228, "IEEE Software Safety Plans", which addresses the planning of the management and technical aspects of the safety system software development process to identify, hazards associated with the software design. The nuclear industry, relying on the techniques identified in the above standards, felt a need for the analysis of abnormal conditions and events (ACE) when a digital computer is used in the design of safety systems in nuclear power plants. The paper identifies the requirements for performing an ACE analysis during or after completion of a computer system design and the methodologies that could be used when preforming the analysis.