Learning Activity 11-18: Creating a Network Diagram and Calculating Critical Path for Case Study

GOALS

The goal of this activity is to apply network diagramming and critical path calculation to a more complex project: the case study.

MATERIALS

Handout 11-5: Project Case Study (already distributed)
Work breakdown structures created in Learning Activity 11-15
Post-It notes
flipchart paper.

TIME

approximately 60 minutes

INSTRUCTIONS

This exercise will require a great deal of assistance from the facilitator and should only be attempted after the completion of Learning Activity 11-15.

Each team should make new copies of the activities from the WBS onto fresh Post-It notes, preserving their earlier WBSs for cross reference. Next they should perform a rough estimate of each task ‚ s duration (not being overly concerned with precision of estimates). After transferring the estimates onto each activity, teams will determine dependencies and create a network diagram, trying as much as possible to allow parallel activities to exist (just as they did in the ‚“party exercise ‚½). Have them include a milestone (zero duration) task for ‚“Start Project ‚½ and for ‚“End Project ‚½

Often it is desirable to use a second Post-It note to place under each task with a grid for entering Early Start, Early Finish, Late Start, and Late Finish. Each task should be represented by a figure similar to those used for the tasks in the Party Exercise.

Have them determine task dependencies to create their network diagrams, just as they did in the Party Exercise.

Review their network diagrams to be sure they have included all tasks from their WBS and that the dependencies make sense.

Following the model of the party exercise, teams then would perform forward pass and backward pass calculations.. The same rules apply:

Rule #1: In forward pass, ES=latest EF of predecessor

Rule #2: In backward pass, LF=earliest LS of successors

Rule #3: Task is CRITICAL if ES=LS and EF=LS (no Slack )

Rule #4: Task is NON-CRITICAL if ES<>LS and Slack=LS ES (or LF EF)

Have teams highlight the borders of the critical tasks and pencil in the slack times for non-critical tasks. (See Rule 3 for Critical Tasks. See Rule 4 for Slack.)