Lead Time: the time between the beginning of a process or project and the appearance of its results. 参见《韦氏大词典》 生产周期: 产品从开始投产至产出的全部时间。(见百度百科http://ke.baidu.com/link?url=h5ll5BBuiDKXSx_Qe-8rDW_3vTI4EptfqAZaDyFZ716m4yyZwCRfhDKuNfswPcbnzVbVLRNUj5k-oZ1DcarQPa)