Gantt

Abstract

The Gantt chart is a helpful tool that can be used to visualize project scheduling. The chart takes it name from its inventor, Henry Gantt (1861-1919). The chart can be used to simplify complex situations and problems by shedding light on actions that should be taken to avoid idleness. Gantt charts are a type of bar chart where the activities that a project consist of are plotted on the vertical axis and time is plotted on the horizontal axis.The activities are shown as bars with length and position relative to their duration and timing respectively. Traditionally Gantt charts would be plotted by hand using pen and paper. This limited the usability of Gantt charts as they required to be remade if unexpected changes in the planning schedule occurred. However, this issue has subsequently been addressed by the use of modern computers. This has made Gantt charts much more flexible as they can easily be altered if a situation prompts changes in the schedule. Originally Gantt charts were applied to mostly to industrial production processes but it can be applied to any planned human activity. This article will discuss the Gantt chart as a project management tool and go over its applications, limitations and implementation.

Historical perspective

The Gantt chart is named after Henry Gantt (1861-1919), an American engineer and consultant who developed the chart between 1910 to 1915. A similar chart was however developed in 1896, around 15 years prior, by Karol Adamiecki, a polish engineer. Although Karol Adamiecki, developed a similar tool to the Gantt chart prior to Henry Gantt, he did not publish his work until 1931, and did not gain the same international recognition as Gantt’s.

Henry Gantt’s charts were originally applied to production planning in industrial factories. During the first world war Henry Gantt was appointed to consult in the manufacturing of ordnance by General William Crozier in 1917. As larger orders were placed, the productions quantities had increased ten thousand-fold, and the conventional charts were deemed inadequate as they did not emphasize time . General William Crozier found that Gantt’s charts were useful, to “fix responsibility for action or lack of action” . The following year, the chart was adopted throughout the United states arsenals and other naval production facilities. After the war, Henry Gantt proceeded with his civilian consulting practice and his charts became widely recognized in the years between the first and second world war. By implementation of the Gantt Chart in production planning, managers were enabled to focus on overcoming productivity issues and avoiding hold ups. In cases where delays were unavoidable the manager would be able to inform costumers in advance. Contemporary literature discussed how Gantt charts could be applied not only to production planning, but also for project management. In the 1950s Gantt charts fell out of popular use in production planning as large-scale productions were deemed too complex. The concern of Gantt charts not being able to handle over complex issues, was however remedied by modern personal computers. Instead of re-drawing charts by pen and paper, if changes to the schedule occurred, interactive software now enabled managers to easily update and re-evaluate charts.

Gantt charts in project management

In project management, large and complex systems are separated into smaller, more manageable parts. Breaking down a project into achievable elements makes it easier to gain an overview of the tasks at hand and to delegate out the work [6]. As the individual elements are part of a whole, they will also depend on each other. These dependencies are important to identify, in order to successfully integrate the elements and make the project coherent. Especially the duration and timing of work is important when dealing with interdependent elements [6]. For more information on the subject of dividing project work into manageable elements see: [Link to WBS wiki-entry] When the project work has been separated into smaller tasks and their dependencies has been identified, the tasks can be organized in a schedule. The schedule is developed by arranging the elements in logical order according to what elements precede and proceed one another [6]. Proper scheduling is essential to avoid project work having to be re-worked and to avoid idleness. Furthermore, schedules can act as milestones that both motivate work and gives an overview of project advancement.