底层部分 meaning in English

bottum fraction

They too must be involved in the planning of projects , especially in the lower levels of the work breakdown structure
他们也一定要参与到项目计划中来，特别是在工作细分结构的底层部分。
On the other hand , field - control layer , as the ground floor of corporation information system , must be integrated with manufacture process managing layer and operating layer
另一方面，现场控制层作为企业整个信息系统的底层部分，必然需要与生产过程管理层和经营决策层进行集成。