The improvement of working conditions (IWC) has, during the 1970s, been the object of both intensive debate and policy seeking to alter the rules of work organization. This thesis studies the main issues at stake in this newly identified area of social policy. IWC has been especially concerned with the finely divided work tasks of large batch production. The trend in occupational health risks and the change in the attitudes of workers have provoked a reassessment of the effectiveness of the taylorist and fordist methods of organization. There has been a significant increase in experimentation with new methods of work organization. On the basis of three case studies, this research analyses the main components of these innovations, their economic impact, their relationship with personnel management methods, and their long term effects. The reasons for the relative failure of these innovations are also analyzed. As concerns the framework of industrial rules governing work management, IWC has encouraged major procedural changes: a limitation in the role of law, active personnel policies by enterprises, and a decentralization of industrial relations. State policy, employers' policies designed to promote greater flexibility, and union attitudes to work organization, and the workers' participation are also analyzed from 1968 until the 1982 "Auroux laws". The articulation between the issues of substance (the implementation of IWC) and of procedure (the level and the actors involved in work organization), has favored a neo-liberal view of work management. However, the longer term implications of IWC are to be found in the attempts to go beyond the models of mass production. The methods of neo-classical economics, the study of industrial relations, and more structural analyses of work management are used.