For the single machine production system under the condition of optimal cycle time equal or great to balance time, Xiong and Leachman found a real optimal buffer trajectory which is independent of initial inventory and gave a formula to calculate the time from any point in inventory space to the optimal buffer trajectory. We can stabilize the system on the optimal trajectory with quickly balance technology(QBT) to save money for the manufacturers. They compare their results with CLB policy and CLW policy a...