forward pass notation

The goal of the forward pass is to determine the earliest time that an event could take place. For example, what is the earliest that a project or activity might be started and finished?

To show the data on the forward pass, two additional elements are added to the arrow diagram picture. The first element is the duration of each activity. The duration of the activity should be shown in the center of an activity's arrow.

arrow diagram duration

The second element added to an Arrow Diagram for the forward pass are "Early Event Time" boxes. The early time boxes are placed above each node. The figure below shows the correct placement of the Duration and Early Event Times on an Activity Diagram.

arrow diagram early event time

These boxes refer to the Early Event Times of each node and not the "Early Start" or "Early Finish" of the activity. This is because these times refer to the Event at the node. If several activities start and end at a given node, then the Early Even Time becomes, for some, the "Early Finish" time, for others, the "Early Start" time.