Computer Control and Human Error

Computer Control and Human Error presents accounts of various incidents at computer-controlled plants. These incidents include equipment and software faults; treating the computer as a "black box"; misjudging the way operators respond to the computer; errors in the data entry; failure to inform operators of changes in data or programs; and unauthorized interference with peripheral equipment. The discussion then turns to the use of hazard and operability studies (Hazops) to prevent or reduce errors in computer-controlled plants. The book describes the conventional Hazop as used in the process industry and an overview of the different Chazop frameworks/guidelines suggested by engineers and researchers. It then presents new Chazop methodology which is based on incident analysis. The final chapter presents reasons for failures in computerized systems, each of which is illustrated with an example. Most of the examples did not cause an actual safety problem, simply because they occurred within systems that are not safety-related. Some of these examples appear in the literature; others are from personal experience or from private communications.

Trevor Kletz, OBE, D.Sc., F.Eng. (1922-2013), was a process safety consultant, and published more than a hundred papers and nine books on loss prevention and process safety, including most recently Lessons From Disaster: How Organizations Have No Memory and Accidents Recur and Computer Control and Human Error. He worked thirty-eight years with Imperial Chemical Industries Ltd., where he served as a production manager and safety adviser in the petrochemical division, also holding membership in the Department of Chemical Engineering at Loughborough University, Leicestershire, England. He most recently served as senior visiting research fellow at Loughborough University, and adjunct professor at the Mary Kay O’Connor Process Safety Center, Texas A&M University.