A Gantt chart is a type of bar chart developed by Henry Gantt to illustrate a project schedule. Gantt charts show the start and finish dates of the terminal and summary elements of a project. Gantt charts also display the expected duration of each stage of a project as well as the expected order of each stage.
The axes of a Gantt chart include the duration (weeks, months, and so on) of each step of the project and descriptions of each step. Gantt charts can also show the completion rate of project steps that are currently underway.
Gantt charts are used in many types of projects, including technical projects and simple projects. Today they are commonly used, but when they were first introduced Gantt charts were revolutionary.
Relevance to Management
Gantt charts are especially useful for management professionals because they display multiple steps and active components simultaneously. Management is tasked with understanding a wide variety of processes at any given instant and allocating resources or adjusting policy based upon this understanding. Gantt charts enable real-time tracking of each phase of a given project (or series of projects), and allow managers to quickly update and communicate broad arrays of information chronologically.
Advantages Of Gantt Charts
Gantt charts can be used to show the current schedule status using percent-complete shadings and a vertical "TODAY" line. Because they are so commonly used, Gantt charts can be used and understood by audiences around the world.
Gantt charts also help communicate the goals and objectives of projects, their timeline, and the expectations project managers have for completion rates for the project. They serve as a communication device among team members to discuss the goals of the project and make realistically appraisals of the current timeline. Thus they provide a useful visualization of strategy in action.
Disadvantages Of Gantt Charts
Although a Gantt chart is useful and valuable for small projects that fit on a single sheet or screen, they can become too large and unruly for projects with a large number of concurrent activities. Larger Gantt charts may not be suitable for most computer displays.
Because Gantt charts focus primarily on schedule management, they represent only one of the triple constraints for project management (cost, time, and scope–Gantt charts show only time). Moreover, since Gantt charts do not convey the size of a project or the relative size of work elements, the magnitude of steps behind schedule can be easily mis-communicated. If two projects are the same number of days behind schedule, the larger project has a larger effect on resource utilization, but this difference is not expressed on a Gantt chart.
Construction of Gantt Charts
In the following example there are seven tasks labeled A through G . Some tasks can be done concurrently (A and B) while others cannot be done until the predecessor task is complete (C cannot begin until A is complete).
Additionally, each task has three time estimates: the optimistic time estimate (O), the most likely or normal time estimate (M), and the pessimistic time estimate (P). The X axis displays the expected duration of the project and the bars show how much time each step of the project is expected to take as well as when the step will take place in relation to the rest of the project.
Gantt chart
Gantt charts are used in project management scheduling.