On the Social Psychology of the Safety Factor: A Case Study in the Sociology of Engineering Science

Selected aspects of a heuristic programming study of the design behavior of a practicing mechanical engineer are described. The study documents the tremendous influence that personality and social variables exert on the technical practice of engineering design. The study bears testimony to Churchman's inseparability thesis [Churchman, C. W. 1968. Challenge to Reason. McGraw-Hill, New York.], i.e., that without our developing some sophisticated notion of what the “system” as a whole is like, the components or subsystems of a system can only be identified and studied with difficulty. The conclusion of the study is that, contrary to most theories of the engineering design process, the behavioral and technical aspects of design are highly inseparable. In certain instances, the influence of behavioral factors on design outweighs the technical factors.