Project managers commonly use both Gantt and program evaluation and review technique, or PERT, charts to display tasks required for task scheduling and project completion. A main difference between Gantt Charts and PERT charts is that Gantt is a bar chart, while PERT is a flow chart. They are probably the best-known project management charts.
Gantt History and Description
The Gantt chart was introduced in 1917 by Charles Gantt and focuses on task sequence. Each task is represented as a horizontal bar showing the length of time it will take to complete.
PERT History and Description
PERT charts were developed by the United States Navy in the 1950s to help manage very complex projects. Each chart begins with an initiation node that branches out into networks of tasks.
Time and Relationships
Gantt charts emphasize the time it takes to complete tasks, while PERT charts emphasize relationships between tasks.
Linear Vs. Interconnecting
A PERT chart might have several parallel or interconnecting networks of tasks, while a Gantt chart is linear. Any relationships between tasks on a Gantt chart are depicted with arrows.
Straightforward Vs. Complex
PERT charts often are designed for only parts of projects and end at the major review points. Gantt charts, on the other hand, work well for more straightforward projects that most likely will not require mid-stream changes.
Limitations
Project managers often use both types because Gantt charts do not effectively illustrate the dependency of one task upon another, while PERT charts can be complicated and confusing.
