1. Network Scheduling : Precedence Diagram Method

2. In AOA and precedence diagramming, the activities are represented by nodes rather than arrows.

3. PDM Logical Relationship
The left side of the PDM node is designed the “start side” and the right side is designed the “finished side”.
Because of the importance of the side, PDM uses arrowheads to identify the direction of relationship.
Precedence diagramming allows more flexibility in modeling relationship than AOA diagramming. AOA diagramming allow only one kind of logical relationship : a preceding activity must be complete before any succeeding activity can begin.
The four logical relationship used by PDM are : Finish to start, Start to start, Finish to finish, Start to finish

4. FS Relationship The most common precedence diagramming relationship.
The succeeding activity cannot start until he preceding activity has been completed.
FS relationship can be expressed in three forms if lag is used, zero lag, positive and negative lag.

5. SS Relationship