Abstract: This is a dynamic dispatching method for delivery performance by a factory. SLACK=(Due.sub.-- Date-Now)-(Forecast.sub.-- FAB.sub.-- Out.sub.-- Time); where Due.sub.-- Date=Scheduled due date from Master Production Schedule. The OTD (On Time Delivery) dynamic dispatching method focuses on the due date and the target cycle time under the environment of integrated circuit manufacturing. SLACK policy controls the long term due date and the OTD policy reflects the short term stage queue time. Through fuzzy theory, SLACK and OTD policies are combined as a dispatching controller to control the lot priority of the entire production line. The work piece, with either a long stage queue time, or with an urgent due date is pushed through the overall production line instead of jamming the front end of the process. A demand pull system satisfies the due date and the quantity of monthly demand.