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WBS is nothing but Work Breakdown Structure. It is mainly used in Project System (PS) module. Tcode: CJ20N. For any project defined we must have atleast one WBS. Within this WBS we can have networks. Networks are nothing but the series of activities. Material are used to perform the activities.
The WBS is a Project Planning Roadmap. A well run project is a work of art, created with a variety of components, both strategic and tactical. Tasks and activities are two of the most important tactical components, forming the basis of the project work effort.