Gantt Charts as a Tool for Project Management

This article is written in connection with course 42433 Advanced Engineering Project, Program and Portfolio Management at The Technical University of Denmark in the autumn of 2015.

A project is a unique set of processes which consist of different activities and tasks to be performed before reaching the project objectivities. During a project unique and complex problems are solved under un-predictable conditions, varying collaborations and great time pressures. All of these characteristics make it incredibly difficult to manage the individual flows of the project. However there are tools that help project managers to manage the project planning and monitoring the schedule to keep track of all activities that needs to be performed. The most common tool is the Gantt Chart because of its simplicity and easy application to any project. It forms a baseline for the lifetime of the project to measure if it is on track or not. Furthermore it helps organizations understand what they are achieving and what they wanted to achieve.

This article aims at providing information about Gantt Charts as a planning/monitoring tool for complex projects and how to apply and benefit from them in project manage-ment but also what challenges and limitation there are to the tool. This article is based on the course material as well as literature reviews of scientific research papers and other influential publications on the subject, Gantt Charts, within the academic fields of Advanced Engineering Project, Program and Portfolio Management.

The Big idea

The earliest Gantt chart appeared in the 1890s. It was created by a Polish engineer by the name of Karol Adamiecki who ran a steelwork in the southern Poland. He was in-terested in different ideas and techniques within management. But 15 years later an American engineer, Henry Gantt, came up with his own version of the chart during his work on the construction of Navy ships during world war one. His version of the chart eventually became widely known and popular and therefore Henry Gantt was the one who laid name to the chart. The Gantt chart has changed very little over the past 100 years and is still thought of as an essential project management tool because of the many advantages that the chart provides.

Figure 2: Karol Adamiecki (1866-1933), Source: http://projectmanagementhistory.com/The_Harmonogram.html

Figure 3: Henry Gantt, Source: http://www.manufactura.mx/industria/2011/06/17/padre-de-la-gestin

The tool is very commonly used in project management because it gives a clear overview of:

• What the different activities within the project are
• When each activity is initiated and when the deadline is
• How long the activity lasts
• Overlap between activities and by how much
• The start and end of the entire project

The main objective of a Gantt Chart is to estimate the duration of a project and to establish the order in which the different tasks that need to be carried out.

Application

Gantt charts used to be prepared by hand and therefore the chart needed to be redrawn every time there was a change in the project which posed some limitations to the usefulness of the chart. However with the invention of the computer along came project management software which makes the tool much easier to handle and update when changes occur.

The Gantt Chart is build up around three key elements: the grid, the task bars and the time scale. The grid is built up as a matrix consisting of vertical and horizontal lines that cross with one another, creating a number of boxes that represent a single unit of time. The time scale is placed on the horizontal axis and can be set to any time interval be it a day, a week or a month etc. The time interval is most likely to change as planning progresses but can with the use of computer software easily be adjusted. All activities are listed vertically to the left of the chart. In Figure 1 the tasks have been named: Task 1, Task 2, Task 3 etc. but in real Gantt charts the task description should be meaningful in order to clearly communicate the purpose of the task. The horizontal task bars are the heart of the Gantt chart. They show where an activity begins and ends. Simple, quick and with a clear visual impact they give a wealth of in-formation. Once the grid has been filled with taskbars and dependencies the chart will hold the majority of the key information needed to analyze and monitor the project as it pro-gresses.

Figure 3: Example of Gantt chart, Source: Orr, 2003

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Creating the Gantt chart step by step

Step 1: Identify tasks The first step in making a Gantt chart is to identify the various tasks that need to be done in order to reach the project objectives. In order to do that the project manager meets with the people involved with the project and gathers information about the main activities that needs to occur in order to complete the project. This result in a very broad plan showing key sequences of events that needs to occur.

Step 2: Analyze tasks Next up is performing a detailed analysis of the tasks to be undertaken in order to get an understanding of the attributes related with each task. This includes resources, timescale and dependencies. This is important due to the fact that all attributes are linked closely together – adjusting one will affect the other! An example of this could be adding human resources to a task which will result in saving time for completing the task but could increase the cost. The fact that all attributes are linked can make it difficult to know where to begin however the simplest place to start is the task duration. How long a task will take is often estimated by the people responsible for performing the task based on previous experiences with similar tasks from the past and what the requirements are for achieving the task. Having experiences with similar tasks is a huge benefit because it makes it possible to adjust the requirements for achieving the task based on any difficulties that they may have come across before, making the task run more smoothly.

Challenges

The Gantt chart is an amazing tool but on its own it will not ensure the success of a project because of the many challenges a project is met by during its lifetime. It needs to be accompanied by a skillful project manager that can control and monitor the progress of the project and seek to make continuous improvement. In the following section the most important challenges to making a Gantt chart are described and how to handle them.

Dependencies

Some tasks can overlap each other because they don't depend on each other but on the other hand some tasks may be dependent on one another and therefore it can be useful to use indications of dependencies that link related tasks together in the Gantt chart. Dependencies can be described in various ways: finish to start, start to start and finish to finish as shown on Figure 4. They are illustrated on the Gantt chart as small vertical arrows running between the tasks. The most common dependency is finish to start indicating that one task needs to be finished in order for the next to begin. Start to start dependencies means that two tasks are started at the same time however this does not mean that they are completed at the same time. Finish to finish dependencies indicates that the tasks are finished at the same time but the beginning of them can be initiated at different times.

Figure 4: Dependencies, Source: Orr, 2003