A framework for achieving safety-integrity in software

Computer-controlled plants and equipment are becoming increasingly important in the quest for greater efficiency and profitability in UK industry. Computers (or the more generic term used by HSE-programmable electronic systems (PES)) offer potential advantages to safety by, for example, providing better information about potential dangerous situations before they occur on a plant. However the sophistication and flexibility of PES call for great discipline and attention to detail in all stages from conception to operation if they are to be successfully and safely employed. The author examines a number of incidents involving PES, drawing out common themes. An overview of the concepts and principles behind HSE´s guidelines on PES is given and a further development of the guidelines which aim to strengthen them in the area of software engineering, is described