Question

What is the critical path of the network?

Answer 1

      Critical means something very important. Hence, critical path of a network means a series of well-defined instructions or steps for achieving a pre-defined target within the available time frame. It is determined by taking into account the longest time frame that can finish an activity or a project and how can one complete all the tasks by reducing the time duration, without compromising with the quality of work being done or performed.

       The concept of critical path is not so new but has its roots going back to 1950s. This concept is very useful in managing any project and saving time. If any of the activities being placed in the series of critical path change, it can immensely affect the end date of the completion of the project. The entire project is divided into smaller activities with a defined target and time frame. A network schedule of all the defined activities needs to be prepared.

        The critical path works on the principle of early start means early finish i.e. ‘Early start + Duration = Early finish’, where early start means the earliest time of starting of an activity, duration means the time taken to complete that activity and early finish means the earliest end to the activity being performed. Even after taking care of a number of aspects, it is possible that the work is not started on the right time. To avoid this last minute problem, another plan with ‘Late start + Float = Late finish’ is prepared, which lays down the latest time at which the project can be started, float means the time by which the activity would be delayed and late finish represents the latest time at which the activity would be finished.

          Cost, time and quality are integral components of the critical path of network. It is possible that an activity has more activities underlying in it. In order to move to the next step, it is important to complete these activities first. Any delay or avoidance of these activities will directly lead to delay in the completion of the project.

An example to understand this concept can be the building of a house. The first step would be to dig foundation which could take up to 8 days, followed by building of walls which can take 10 days, followed by building of roof which can take 9 days. The critical path will include 27 days but if windows are to be made and fixtures are to be installed which can take 5 days, these work can be done during the last stage of completion. Hence, these can be done in the last 4-5 days without increasing the time frame of 27 days. This is because the critical path is being identified as building of house with four walls and roof.