A store-level DRP forecast immediately accounts for any changes in end customer sales, with the result that increases in sale automatically cause calculated purchases to move closer to today, and decreases in sales automatically cause calculated purchases to move further into the future. Update to the network forecast are rapid, with weekly, daily or real-time updates as achievable norms. Such forecasts virtually eliminate bull-whip effects, enable participants to optimize capacity and throughput planning, eliminate waste, and improve value-added processes