考虑了包含多阶段和多家零售商在内的混合按订单生产 (Produce-to-Order)
     和提前生产  (Produce-in-Advance) 策略库存模型.  将这一模型推广至多种产品情况下,
     当需求为正态分布时, 将这一问题转化为一类多目标约束最优化问题, 并给出两种算法来解决这一问题.  

We formulate a general mixed produce-to-order and produce-in-advance inventory model having multiple stocking echelons
and multiple retailers. It is shown that the problem to find an optimal inventory policy  with a normal demand distribution can be reduced to a general constrained optimization problem. It can be changed into a multi-objective optimization problem. Finally, two numerical examples are given.