This thesis is an examination of the selection, introduction, use and effects on job design and work organisation of a particular form of new technology: Computer Numerically Controlled machine tools (CNC). Part One, Chapters 1 - 6, reviews the new technology literature and the historical development of contemporary approaches to job design and work organisation. From this examination, a conceptual framework is constructed showing the factors which influence and guide the choices that organisations make with regard to new technology. It draws special attention to the role played by the values, beliefs, self-interest and power of individuals and groups within organisations, and the philosophy and precepts of Scientific Management. The section concludes by describing the aims, objectives and methods of the research, and by examining the development of, and literature regarding, CNC. Part Two, Chapters 7 - 10, presents case studies of the introduction and use of CNC into nine engineering companies, differentiated according to company size and product batch size. Part Three, Chapter 11, presents the conclusions from the study. It firstly compares the case studies with each other, and then with the conceptual framework. It shows that the empirical studies supported the framework, but that two additional factors need to be taken into account: (a) that there is a need to recognise that those involved in the process of technological change can be "dazzled" by the technology, and (b) that the change process can be significantly affected by the competence of those involved. Nevertheless, the conceptual framework, and especially the influence of Scientific Management, are confirmed. The Chapter concludes by putting forward guidelines for the introduction of new technology.