The method and system of the present invention use a plurality of timing data to determine a transportation schedule or schedule(s). The transpiration schedule or schedules include a series of precise timing windows for pickup and delivery of products moving from suppliers to plants. In addition, the products may move thorough cross docks and other suppliers. Further, the suppliers in the system may belong to different tiers in the supply chain. The schedule(s) are then transmitted to all of the effected parties. If the schedule(s) are not accepted and/or certain scheduling variables change, the schedule(s) may be recalculated and retransmitted.