How can you use program evaluation and review technique to track construction project progress?

2 Step 2: Estimate the durations

The next step is to estimate the durations of each activity. Unlike other scheduling techniques, PERT uses three estimates for each activity: optimistic, most likely, and pessimistic. The optimistic estimate is the shortest possible time to complete the activity, the most likely estimate is the most realistic time, and the pessimistic estimate is the longest possible time. These estimates account for the variability and uncertainty of the activity durations. You can use the following formula to calculate the expected duration of each activity:

Expected duration = (Optimistic + 4 x Most likely + Pessimistic) / 6

3 Step 3: Draw the network diagram

The third step is to draw the network diagram that shows the relationships and sequences of the activities. You can use circles or nodes to represent the activities and arrows or lines to represent the dependencies. The arrows should point from the predecessor activity to the successor activity. You can use different types of dependencies, such as finish-to-start, start-to-start, finish-to-finish, or start-to-finish, depending on the logic of your project. You can also label the arrows with the expected durations of the activities.

4 Step 4: Analyze the network diagram

The final step is to analyze the network diagram to track the progress of your project. You can use two methods to do this: forward pass and backward pass. The forward pass calculates the earliest start and finish times of each activity, while the backward pass calculates the latest start and finish times of each activity. The difference between the earliest and latest times is called the slack or float, which indicates how much time an activity can be delayed without affecting the project completion date. The critical path is the sequence of activities that has zero slack and determines the shortest possible duration of the project. You can use the network diagram to monitor the status of each activity, update the estimates, and adjust the schedule as needed.