However, for long time, only regulatory control has been implemented in PVC production, aiming at some particular craft process, equipments and products, can't satisfy the flexible request in system.

然而，长期以来，在PVC生产过程中仍采用常规控制的方法，仅针对于某一特定的工艺流程、生产设备和产品，无法满足过程对控制系统柔性的要求。

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