A critical path is a sequence of interdependent activities or tasks that must be finished before the project can be finished. It is the longest path (i.e. path with the longest duration) from project start to finish. At the same time, the longest path is the path that shows the minimal time in which a project can be completed. If there is a delay in one activity of the path, the whole project will be delayed accordingly.
The critical path method (CPM) is a very effective tool for scheduling tasks and keeping track of activities by visualizing them in a network diagram, such as a Gantt chart. In such a diagram activities are depicted as a network of arrows that connect two event nodes. It is important that all interrelated activities are clearly outlined in order to have a functioning network of events and activities. One of the biggest advantages of the critical path method is that it allows for adjustments during the process of a project.