Specification of software for emergency shutdown system of an offshore installation

The process dealt with is the conversion of a rather loose `requirement´ for the emergency shutdown (ESD) system of a major offshore installation into a tightly defined specification for the software (SESD) of that procedure is broadly shutdown systems for other kinds of plant. The fusion method of object-oriented analysis is outlined and is applied to a system based on the Tern Alpha platform, whose basic features and shutdown requirement are described. The system requirement that is adopted provides not only several levels of shutdown, each encompassing a wide range of equipment, but also more targeted unit shutdowns. Consideration is given also to the use of ESD data to inform platform operating staff of incipient failures of monitored equipment and of the system SESD itself. The Fusion Method is used to assemble information relating to the installation and shutdown process in a form appropriate for the specification on which the design of the system SESD can be based. Some limitations of the method are identified