Figure 1 Precedence Diagramming Method Example
In this network diagram, the activities are represented by boxes (node) and the logical relationships between the activities are presented by arrows. PDM allows the use of the four types of relationships that are finish-to-start (FS), finish-to-finish (FF), start-to-start (SS), and start-to-finish (SF). Figure 2 shows the representation of these different relationships. This approach is the most common one and supported by major scheduling software such as Primavera and MS Project.
Figure 2 Relationship Representation in PDM
Figure 2 Relationship Representation in PDM
The second type is the Activity-On-Arrow (AOA) as shown in Figure 3. In this network diagram, the activities are represented by an arrow and connected by nodes. The nodes represent an event which could be the start or completion of an activity. Finish-to-start is the only relationship that can be used to express the dependency between activities when using the AOA approach. Sometimes it is necessary to use a dummy activity, which is an activity that has no time, to maintain the logical relationships in an AOA network.
Figure 3 Activity On Arrow Example
If you have any questions, please do not hesitate to ask.
Figure 3 Activity On Arrow Example
If you have any questions, please do not hesitate to ask.
In future posts I will talk about the logical relationships between activities, how to construct an AOA network, and finding the critical path.
