The verification of throughness of workflow logic is very expensive both in time and space. The state ex- plosion is the main difficulty.

工作流的畅通性验证无论在时间上还是空间上代价都是非常高的，状态空间爆炸是验证的主要困难所在。

During the process of pulling and stretching, the quality of pulling and strething parts mainly show: wrinkle, plosion thin, rebound, lug etc.

在薄板拉深过程中，拉深件的质量问题主要表现为起皱、破裂、变薄、回弹、凸耳等。