This paper examines the relationship between a managerial focus on improvements in efficiency and value added. We analyze financial information on 915 non-service US firms with total assets over US $100 million over the 25 year period from 1980 to 2004. Our results show a very strong correlation between the increase in value added and the increase in inventory speed across all manufacturing industries. The results strongly support the operations management literature which claims a managerial focus on efficiency, in particular increases to the speed of operations, will result in significant value creation for firms. The results also imply that the concept of competition based on operational speed has not been transferred across all firms and the potential for improvement still exits in most industries.