Activity network diagram

A project network is a graph (flow chart) depicting the sequence in which a project's terminal elements are to be completed by showing terminal elements and their dependencies. The work breakdown structure or the product breakdown structure show the "part-whole" relations. In contrast, the project network shows the "before-after" relations. The most popular form of project network is activity on node, the other one is activity on arrow.
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An arrow diagram used in planning and managing processes and projects.