As described in the opening of this chapter, the schedule network captures the logic of the project, reflecting in its structure the dependencies and relationships among tasks on the WBS. The network we will concern ourselves with is commonly referred to as the PDM. In a PDM network, the tasks of the WBS are represented as nodes or rectangles, and arrow-pointed links relate one task to another. In fact, we can think of the components of a network as consisting of building blocks.