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. Critical tasks, noncritical tasks, and slack time Shows the relationship of the tasks to each other Allows for what-if, worst-case, best-case and most likely scenario
Key elements include determining predecessors and defining attributes such as early start date late start date early finish date late finish date duration activity name WBS reference
Slack/Float: Determines the duration of activity delay that the project can tolerate before the project comes in late. The difference between the earliest and the latest start time. i.e. Slack = latest start date - earliest start day or Slack = latest finish time - earliest finish time.
Any activities which have a slack of 0, they are on the critical path.
Different Precedence diagram Methods Arrow diagramming method Project network Critical-path method Gantt chart Program evaluation and review technique
References
Further reading
External links Precedence Diagram Method at Better Projects