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The Activity Network Diagrams, PERT and Critical Path Method

There have always been different techniques used in project management and planning for centuries but in the previous century there was the fastest development. Several techniques and methods were used for efficient and quick project planning: activity network diagrams, PERT and critical path method to name a few. All these techniques were designed to efficiently manage small and big projects by removing all the factors that could delay the project if not given proper resources. You can read about all the three main techniques one by one to get more information about them: the modified form of critical path method is the most common one in use today.

Activity Network Diagram

It is a tool or method that helps a project manager in plotting the sequence of time of procedures or activities that could directly affect the in-time completion of a project. Task times, critical tasks and slack times are some of the main components are studied while applying this method for project management. For the presence of arrow like shapes in the diagram, it has been given the name of arrow diagram. Another name for a similar technique is PERT which stands for program evaluation review technique.


The definition of program/project evaluation and review technique (PERT) would seem pretty much similar to that of critical path method. However, there is a slight and subtle difference but both techniques were brought into existence at almost the same time. To define PERT in simple words, it is a representation of a project in the form of a road map which gives a project manager the idea about time taken for individual tasks, their internal dependencies and completion dates. Obviously, when you start on a project you already have a deadline and it is up to you to decide when to start the project. A representation of each element involved within the project will give you an idea of what time will be most suitable to start the project and end it before the deadline – unless of course you don’t want to end the task right on the deadline.

Critical Path Method

Critical path method as the name implies is putting all the processes of a project on a chart where you can see them individually; see what their correlation is; what time is perfect for starting a particular task within the project and when it would be best to end a task so a next one could be started. When you go along the critical path, you want to make sure that no process within the project is hidden from you and that you have information about the commencement and completion of every task: if that information is not available, you wouldn’t be able to apply the technique in the first place. This is a technique widely in use today in companies however not exactly in the form it was introduced in.

Benefits Of AND, PERT And CPM

The benefits of these methods are undeniable in any project whether on a small or a large scale. Starting a project comes with greatest challenges in the form of meeting deadlines. While it looks to an outsider that a project has only one deadline at the end but for a manager there are deadlines involved in every task. Though the application of these methods could be argued in extremely difficult and complex project but the project where they are applicable conveniently, they serve the purpose of meeting those deadlines efficiently.

When you know where your tasks are heading to and what date they will end on, you will know when to start the next ones. Through critical path method you have a clear idea of each task, its progress and completion: based on this information you can easily allocate your resources depending on the criticality of a task. You wouldn’t have to spend too much time in completing tasks that are of less importance as compared to others. Working on the most critical and essential tasks is of much importance, which is only recognized through these methods.

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