Abstract: A material flow design system for a mixed-model demand flow manufacturing line is presented. The material flow system utilizes a replenishment card/replenishment container system of material management. The material flow design system defines the size of replenishment containers and the location of material deduct points in the production path. The material flow design system may further include a design system for designing an inventory control system. The inventory control system involves locating backflush and intermediate backflush locations on the production path and deduct points in the material flow sequence. An inventory monitoring system monitors material flow, deducts material from inventories at deduct points, and credits material to inventory indicated by the deduct points when products produced by the manufacturing line flow through material backflush points defined in the manufacturing line.