(Alias: precedence network)
The key is not to prioritize what's on your schedule, but to schedule your priorities.
- Stephen R. Covey
A precedence diagram is a graphical method of depicting the sequence of activities in a project. It is represented as a network of arrows and nodes where the nodes represent activities and the arrows indicate dependencies between activities. The diagram also depicts the duration of each task and time lags between the starts and finishes of related tasks.
Precedence Diagram Example
The precedence diagramming method supports the modelling of the following types of dependencies between activities:
||The predecessor activity must be completely finished before the successor activity can start. A time lag may be specified between the finish of the predecessor activity and the start of the successor activity.
Example: The start of Task B must be delayed two weeks after the finish of task A.
||Two activities may start together. A time lag may be specified between the start of one activity and the start of the other.
Example: Task D must start one week after the start of task C
||Two activities must finish together. A time lag may be specified between the finish of one activity and the finish of the other.
Task C must be completed one week before the completion of task B.
Task D must be completed at the same time as task B.