Complex projects are characterized by a series of tasks, some of which should be performed in a sequential manner and other tasks that should be executed simultaneously. According to Perrin , a Program Evaluation Review Technique (PERT) chart is defined as a graphical representation of a schedule in a project, depicting the sequence of activities, which activities can be executed in parallel with others, and the critical path of activities that must be accomplished earlier to ensure that the completion deadline of the project is met. Therefore, the critical path of the PERT chart includes those activities that must be completed on time so that the completion deadline of the entire project is met. In the PERT chart, the critical paths are usually shown in red. The PERT chart enables a team to attend to the most critical activities, to avoid unrealistic schedule expectations and timetables, and to distinguish and shorten activities that are bottlenecks.
In some cases, many tasks of a project are likely to be delayed because of a number of issues such lack of materials, few employees, and equipment breakdown. Some of the tasks may be part of the critical path. For instance, B, C, and D are three tasks that make up a project, where B is classified as being part of the critical path, while C and D are not. If the three tasks have a likelihood of being delayed due to various problems, it is advisable for the project manager to start with the correction of the problems of task B because the task’s delay can lead to the delay of the entire project. The project manager can then correct the problems of the remaining tasks starting with either task C or task D. This is because both C and D are not parts of the critical path and cannot lead to the delay of the entire project in case they are delayed.
Therefore, in any complex project, it is important for the project manager to determine the tasks that lie in the critical path and those that do not. This is to ensure that the tasks in the critical path are completed on time so the completion deadline of the project is met. When various tasks are likely to be delayed due to various problems, the project manager is advisable to start correcting the problems of those tasks that lie in the critical path, which is then followed by correcting the problems of other tasks without following a specific order.