Critical Ratio scheduling has been implemented in job shops that manufacture component parts for stock replenishment as well as direct customer orders. Proponents of this technique argue that scheduling performance is improved by gathering and processing two different types of operating information on a routine basis for use in making priority scheduling decisions: queue waiting time information for individual machines and stock status information from the shop's inventory system. Simulation experiments are reported here which describe the effect on the performance of a shop and its associated inventor' system when using this type of information with an Order Point inventory control system. The results indicate that the additional information provided by the increased data collection and processing functions does not contribute a statistically significant improvement in the overall performance of the production system.