ABSTRACT:This Paper the existing literature on optimal capital utilisation and shiftwork patterns by arguing that labour is not the only input to exhibit a price which varies over the time of day week or year Indeed in certain situations as in the w e of capital intensive industries which are heavy consumers of electricity labour costs may not even be the most important consideration The introduction of a second varying input price can completely alter the optimal operating times of production units Once this extension has been adopted it is a fairly easy final step to demonstrate that some firms face a strong inducement to develop technologies which allow them to use their capital and labour independently This type of technological change has become commonplace in recent years but largely unexplained by the existing literature These developments have important implications for the organisation of work patterns and the flexible use of the labour input