Here is a worked example and process for constructing a network diagram:
Using this example:
Activity Duration (days) Predecessor(s)
A 5 ---
B 2 ---
C 4 A
D 6 B
E 3 C, D
F 1 D
Follow this sequence:
1. Construct the Network diagram.
2. Check the network diagram.
3. Add durations to the activities.
4. Identify all paths through the network.
5. Identify the critical path (CP) and scheduled duration.
6. Calculate slack times (float) for each activity.
1. Construct the Network diagram.
Using the AIB method:
Draw a box on the left labeled "Start"
Add boxes to the right of this box for activities with no predecessors, in the example A, and B. Connect these boxes to the box labeled start, but not to each other! I always start with box A at the top, and others in sequence underneath, vertically.
Add arrows to the end of the lines where they connect to the activity (A and B) boxes. (This is important for step 4).
Draw a box to the right of activity A for any activities which list A as a predecessor. (C in our example).
Connect this box to activity A, don't forget the arrow!
Draw a box to the right of activity B for any activities which list B as a predecessor. (D in our example).
Connect this box to activity B, don't forget the arrow!
Draw a box to the right of activity C for any activities which list C as a predecessor. (E in our example).
Connect this box to activity C, don't forget the arrow!
Draw a box to the right of activity D for any activities which list D as a predecessor. (F in our example).
Connect this box to activity D, don't forget the arrow!
Check for additional relationships. In this