Why the critical path is shortest duration in which the proj

Why the critical path is shortest duration in which the project can be completed? This question deals with quantitative analysis

Solution

The Project Management Body of Knowledge (PMBOK), an internationally recognized collection of processes and knowledge areas accepted as best practice for the project management profession, defines the critical path as “the sequence of scheduled activities that determines the duration of the project.” It is the longest sequence of tasks in a project plan that must be completed on time in order for the project to meet its deadline. If there is a delay in any task on the critical path, then your whole project will be delayed. Although many projects have only one critical path, some projects may have multiple critical paths.

The critical path method is a step-by-step project management technique to identify activities on the critical path. It is an approach to project scheduling that breaks the project into several work tasks, displays them in a flow chart, and then calculates the project duration based on estimated durations for each task. It identifies tasks that are critical, time-wise, in completing the project.

The critical path can be defined in many ways, such as:

Let’s say, you got a project to build three buildings in one location. The first building is the largest building, the second building is medium sized building, and the third building is the smallest building.

You develop the network diagram which consists of three paths; each path resembles each building.

You calculate the duration for each path. For the first building, the duration is 31 months, for the second building it will take 18 months, and the third building will require 13 months to complete.

The first path is for the largest building, the second path is for the medium sized building, and the third path is for the smallest building.

It is thirteen months bigger than the second path, and 18 months bigger than the third path. This means that if you start working on the first building, you can wait 13 months to start work on the second building, because you can complete second building in 18 months.

Likewise, you will have an 18 month wait time to start working on the third building, because it will take only 13 months to complete. This means that even if you start working on the third building after 18 months from the project start date, you can complete it on time.

This waiting period is known as float or slack.

So, which one is the critical path in this network diagram of three paths?

Of course, it is the longest path on the network diagram, because you cannot complete your project before constructing the first building. Although you can complete the other two buildings quickly, until you complete the first building, your project cannot be considered as completed.

Hence, the critical path is the longest path on the network diagram.

Now, tell me that what is the shortest duration in which you can complete the project?

Sure enough, it is 31 months, because you cannot complete your project before 31 months, and this is the duration of the critical path.

Hence, the critical path is the shortest duration in which you can complete the project