The Gantt chart is a tool and an aid to management. Managing employees and a business is concerned with the future and reaching goals. Managers set a standard, create a plan and put practices in place to reach these goals. They must coordinate employees, capital, machinery and assets to ensure business success. Making decisions for the future are often based on what has happened in the past. This is why it is of utmost importance that past actions and progress are tracked. In conjunction with this information, managers also need to know when events took place and the rate at which they took place. The core idea of the Gantt chart is the relation of facts to time. Henry Wallace Clark referred to it as “The Working Tool of Management”. (1)
To put it more plainly, the Gantt chart is a project management tool. They often make a project much easier to track and view progress. Modern Gantt Charts resemble a bar chart. However, the original charts were drawn with lines of varying thickness. The chart is drawn by dividing the page into equally spaced boxes which represent each day of the week. Each box which represents a day is then further divided into equally sized smaller boxes. A description of the information that will be charted is written at the top of the sheet. Each individual task is then written down the margin. Each task is subdivided into numbers which quantify the amount of work to be done e.g. 150. Each day a line is drawn across the day to show the percent of work that was completed. At the end of each week, a manager can view the progress made each day. The thicker line drawn across the entire week is each day added up together. This then shows the shortcomings/ progress of the week in total. (See Fig 1. below.) The Gantt chart has developed tremendously since its origins as technology has taken over the world. Stay tuned for these recent developments.
A more complex version of the Gantt Chart led on from the first simple design. This included multiple projects which had to be completed over a longer time period. Each Project was marked on a calendar-like set up, over weeks or months (see fig. 2 below). This showed a connection between different projects, displaying when one started and when another should begin. An early time approach is adopted in Gantt Charts which maximises the amount of float time available, (Float time is the amount of time a project can be delayed before it impacts the deadline of the project (5).). In this way, the Gantt Chart ties all aspects of a business together, allowing a manager to plan for the future efficiently and effectively.
Although the Gantt Chart we see today is based on Henry Gantt’s idea, it was originally Karol Adamiecki, a polish engineer who devised the chart in 1896 (3). This was called the harmonogram. However, Adamiecki did not publish his work in a popular Western European language, and even though he published his work in 1903, and Gantt published the Gantt chart in 1910, there is no evidence to suggest that Gantt copied his work (2). So we can still appreciate Gantt’s work as an original idea!
In today's post, I will briefly introduce the idea of the different types of Gantt Charts.
The Man Record Chart- The purpose of the Man Record Chart is to show whether or not an employee completes a full day's work and if they don’t, the reason is also illustrated. (6)
The Machine Record Chart- This shows whether or not machines are being used, and if they aren’t it also shows the reason for idleness. (7)
The Gantt Layout Chart- This is used to work out a plan to fulfil orders when they are needed and also to make the most effective use of the available employees and machinery. The best way of illustrating this is by emphasising when jobs are to be done, by whom and the length of each job.(8)
The Load Chart- The Load Chart is very similar to the Layout Chart in that it shows what work is to be done. However, it is in less detail and of more value to managers. It keeps them advised of the load of work which lies ahead of them in the future. (9)
The Gantt Progress Chart- This shows quite clearly the progress which is being made during a plan or program. (10)
Advantages of the Gantt Chart
The Gantt chart requires a plan. Plans give business guidance and direction. This promotes the assignment of clear-cut tasks to subordinates. The plan for the business is presented in a way that allows all members of the business to understand it.
The Gantt Chart is a control mechanism. By comparing what should be done with what was done, a business can measure performance. This allows them to identify faults and shortcomings and quickly take corrective action to remedy the situation.
The Gantt Chart is very compact. It compiles information in a concentrated fashion. This simplifies things for all stakeholders in the business as they can easily interpret what needs to be done.
Finally, by illustrating tasks against the passing of time, idleness and wastage of time can be quickly identified and removed.
After all of that information, it’s time for a review on the Gantt Chart and how it contributed to Gantt’s Management theory. The Gantt Chart increases efficiency in the workplace. It allows a manager to see how productive employees are. They can identify areas that need improvement, processes that may be taking too long or need more time, as well as days where employees are more or less motivated. In my opinion, the Gantt Chart is one of the most revolutionary methods of tracking progress and a core practice in Management Science.
If you like what you see, leave a comment below! We would love to hear from you and answer any questions you may have on Henry Gantt, but especially his famous charts!
https://archive.org/details/ganttchartawork00trabgoog/page/n20/mode/2up, Henry Wallace Clark, 1922- Chapter 1.
https://www.pocketbook.co.uk/blog/2017/03/07/karol-adamiecki-management-harmony/, Mike Clayton, 2017.
https://www.scoro.com/blog/what-is-a-gantt-chart/,
https://www.onepager.com/community/blog/wp-content/uploads/2014/10/early-gantt-chart.png, Nathan Black, 2014.
https://www.wrike.com/blog/what-is-project-management-float/, Jeremy McCabe 2022.
https://archive.org/details/ganttchartawork00trabgoog/page/n20/mode/2up, Henry Wallace Clark, 1922- Chapter 5.
https://archive.org/details/ganttchartawork00trabgoog/page/n20/mode/2up, Henry Wallace Clark, 1922- Chapter 4.
https://archive.org/details/ganttchartawork00trabgoog/page/n20/mode/2up, Henry Wallace Clark, 1922- Chapter 6.
https://archive.org/details/ganttchartawork00trabgoog/page/n20/mode/2up, Henry Wallace Clark, 1922- Chapter 7.
10.https://archive.org/details/ganttchartawork00trabgoog/page/n20/mode/2up, Henry Wallace Clark, 1922- Chapter 8.
by Daniel Roche, 13/10/2022