Since the turn of the century there have been many efforts to enhance the productivity of the workforce. The scientific management approach of Taylor (1947) and the introduction of the assembly line brought wholesale changes in the way that factory work was organized and supervised, and the way in which workers were paid. Research by the Gilbreths (Gilbreth, 1914) and Maynard (Maynard et al., 1948) used scientific means to establish the most effective work methods. These could be considered early attempts at ergonomics. Other theorists and researchers added elements of psychological and social processes to define ways to make workers more motivated and productive (Roethlisberger and Dickson, 1964; McGregor, 1960; Herzberg, 1966; Hackman and Oldham, 1976; Lawler, 1986).