PERT (Program Evaluation & Review Technique) and Gantt charts are used in project management to represent the activities or tasks in a project from start to end. They allow us to visualize the workflow and the project plan. The main difference between PERT and Gantt charts is that they use different methods to present the project data.
The table below enlists the significant differences between PERT and Gantt Charts.
Difference between PERT & Gantt Charts
| Gantt Charts | PERT Network |
| A Gantt chart is a bar chart used to illustrate the individual tasks associated with the project from start to end. | PERT chart is a flow chart or network diagram which illustrates the project tasks along with their interdependencies. |
| Gantt Chart was developed by Henry Gantt around the years 1910 to 1915. | The United States Navy introduced a PERT chart or PERT network diagram in the 1950s. |
| The activities of the project are represented by a bar on an x-y axis. The x-axis represents the time, and the y-axis represents the individual tasks. The position and the length represents the starting, ending, and duration of the activity or task. | Individual boxes represent the PERT tasks. The box carries the details of the task name and the time estimates- optimistic time, pessimistic time, and most likely time. It is not represented on the X and Y-axis. Each task carries the time and details. |
| The tasks or activities can be allotted with a specific time. | A fixed time cannot be provided. Each task is represented using the time estimates. |
| Excellent method for improving time efficiency my time management optimization. | Great method for project with tasks that have large inter dependencies. |
| Gantt Chart is used when the project commences. It breaks the project into smaller tasks and helps to emphasize the scheduling constraints. | PERT network diagram is employed before the project, to plan and determine the time duration of individual tasks. |
| Accurate time duration and percentage completion can be taken from Gantt Charts | Time estimates are determined using past data and prediction. |
| Used for more small, common and repetitive projects | Used for large, complex and non-repetitive projects. |
| Gantt Chart does not show the interconnection between the task. | Numerous interconnections are studied and represented in PERT networks |
| Easy to read the work progress. | The network becomes tough to read with an increase in complexity and interconnections in the project. |
| Gantt charts anticipate the time required to complete each task | PERT networks anticipate the time necessary to complete the project |
Frequently Asked Questions
A Gantt chart is a bar chart used to represent the individual tasks associated with the project from start to end. PERT chart is a flow chart or network diagram which illustrates the project tasks along with their inter-dependencies.
In the Gantt chart, the activities of the project are represented by a bar on an x-y axis. The x-axis represents the time, and the y-axis represents the individual tasks. The position, the length represents the starting, ending, and duration of the activity or task.
Gantt Chart does not show the interconnection between the task while numerous interconnections are studied and represented in PERT networks. Gantt charts anticipate the time required to complete each task while PERT networks anticipate the time needed to complete the project.
Read More: