An activity network diagram also known as arrow diagram, pert chart, and critical path method is used to show activities that are in parallel and/or in series. It will show the most likely times, the most pessimistic times, and the most likely times for the completion of projects.
Use: Let’s say that you are working on a project and your boss wants to know how long the project is going to take. You could give your boss an idea of how long it will take off the top of your head, but since there is a lot of money on the line, you know that your boss wants a more scientific way of determining how long the project is likely to take. With the activity network diagram, you are going to calculate three things.
- You are going to calculate the most likely time.
- You want to give your boss an idea of a range of times. In other words, you want to present the best case and the worst case. You calculate the most optimistic time.
- You also want to include the most pessimistic time.
From that you can calculate some guard bands around the most likely time.
