Precedence diagram method
（重定向自Precedence diagram）
![solving the PDM, with: BS is an early start date. BM is a late start date. KS is an early finish date. KM is a late finish date.](/Images/godic/202502/04/TinhSoDoMangPDM5603.png")
The precedence diagram method (PDM) is a tool for scheduling activities in a project plan. It is a method of constructing a project schedule network diagram that uses boxes, referred to as nodes, to represent activities and connects them with arrows that show the dependencies. It is also called the activity-on-node (AON) method.