The use of Gantt Charts

Revision as of 02:09, 28 February 2021

Abstract

Project management is a big part of any kind of project work, big or small, it is important to maintain a clear overview and keep track of when precisely different parts of the project should be completed, especially if other parts of the project are dependent on each other. To keep a project on schedule it is important that all participants involved in the project know when to start and finish their respective parts, so there will not be any delays. One simple way could be through the Gantt Chart or Critical Path Method, these are simple but excellent methods for getting a good overview and graphic representation of the different elements in the project^[1]. The Gantt Chart is a good starting point, though it does have its limitations. These will also be discussed later in this article. Bigger projects might contain multiple Gantt Charts for different departments or parts which are then merged into one, or it might just be one simple Gantt chart. It depends on the specific projects, as well as who and how they use the Gantt Chart. There exist different kinds of programs for creating Gantt Charts and there is software developed for that exact use but the classic one is doing it in excel sheets. The Gantt Chart is often taught to or suggested for students who study introduction management or project management, because of its simplicity. The problem is that with such a simple tool comes a lot of delimitation which is not often discussed. Therefore, finding out when and how to use Gantt Charts is important.

Introduction

The Gantt Chart is the backbone in the project scheduling part of project management, was created by Henry Gantt, at the beginning of the 20th century. He started developing charts while working in 1902 and 1903 where it advanced to a daily balance chart. then after that Gant further developed his charts when working for American Locomotive Company in 1903 ^[2]. Gantt then worked further on his charts during world war one while he was working for the United States Army and Navy during world war one, this is also where the Gantt Chart truly became known wildly used.

Gantt Charts have since the beginning been used for project management for such as performance and progress charts, and production planning tools^[3]. The reason for the frequent use and popularity is;

1. Visual presentation
2. Simplicity
3. Compactness
4. Adaptability etc.^[4].

In the beginning, Gantt Charts were made by hand and by using blocks of paper^[5], and if it was done on paper it would mean that if there were any changes, the rest of the Gantt Chart from the point of the change would have to be redone, but with the personal computer nowadays there exists specific software to the making of Gantt Charts. A classic example of a Gantt Chart could be a Gantt Chart in excel as shown in the figure below.

The picture above shows a very basic Gantt Chart with dates horizontally in the top and the assignments vertically with the date they need to be done, with basic colour coding in excel. This is often what is taught in introductory business classes or introductory management classes, as mentioned before this is the basic level of a Gantt Chart. Many also choose to use this kind of excel sheet and create a bar chart instead. The reason for this is the simplicity of using and learning how to use the Gantt Chart.

To summarize, the overall point of a Gantt chart is to stay organized in both project management and portfolio management, and during a project and processes.

The Origins of the Gantt Chart

Gantt himself was a teacher and he taught at his alma mater McDonogh, where he taught the subject in clouded mechanical drawing. Evidence that Gantt’s interest in engineering and graphic approach to work and influenced his work with combining graphics and management processes. Which is basically a short description of what the Gantt chart is. It is a graphic solution for showing a process and the subsequent steps in the process ^[2]. he worked for Bethlehem Steel where he was asked to implement a method that could increase productivity, again here Gantt worked the Gantt chart. But as mentioned earlier during world war I cannot work with the American army to coordinate production efforts in 1917. But to be noted that it was first in 1917 that cannot really focus on the graphical part ^[2].

The first chart which looked like the Gantt Chart we know today was actually made by Karol Adamiecki a polish engineer focused on management research, which he later called “harmonogram”^[6]. This was in the mid -1890’s, but he had published his work in Polish and Russian, and because of the language barrier, Henry Gantt had not seen it. Adamiecki created his harmonogram by observing 16 workers, where their ver manly focus on the length of their specific movements, in their specific task, and the time of their rest periods. When done with his research Adamieck had created a chart that could indicate the cause of low productivity, and enhanced the grapichaæ production schedule. The answers were often low harmony in the operation when using the harmonogram. When using the harmonogram often led to an output increase of up to 400 percent. In some areas, the harmonogram had more advantages which made it superior to the Gantt chart. One of these areas is that the harmonogram has the critical path in it ^[6]. and is very much focused on the day-to-day production, whereas the Gantt char is more phase based. But Gantt Chart became more famous since it was written in English and at this point, English was the main language.

Today

Nowadays the Gantt Chart is often used in project management due to its theory of using time and resources when evaluating projects. The Gantt Chart includes all of the phases in a project^[7] and it shows the progress done over a period of time. Therefore people can see what the next step is in the project or process. And at the end of each phase or day, the project manager can look at the Gantt Chart and see its status. The manager can view where it might be behind or in front of a schedule and make qualified decisions on where there might be need for support, or if there is a need for a new strategy in order to keep on track, when evaluating the project efficiency over the time plan^[7]. However, as mentioned earlier, in older days if there where the slightest change the rest of the Gantt Chart would have to be written, but nowadays there are software the link is for webpage with just some of the most popular once ^[8]. Some also choose to incorporate the critical path to get a better understanding of the phase’s connection. The critical path will be explained later.

Application / Creating a Gantt Chart

To create a Gantt Chart there are specific parts and steps which need to be known and completed. The next part will go through this in 4 steps^[9].

Step 1: Identify the needed tasks

For a Gantt Chart to be completed and used to its fullest potential, it is important that all of the steps in the project are included and detailed in each phase. Every task is set up in order of complacency, so that they are done on the correct time. The earliest start date is put first - this is when you expect to be able to start on the specific part. This date can be dependent on an earlier step’s completion date. An estimated completion date is also put into each step, the estimated completion date is important to consider especially if another step is dependent on it. It is crucial that the project manager keeps track of the process of each step especially if another step cannot start without the previous step being done. This way the project manager can be prepared if there are any delays and can prepare if a specific step is done earlier than expected. The different parts are put in order at the start of the day.

Step 2: The relationship between two steps

When writing up the chart in order of the start date it is very important to keep in mind whether some parts are depending on another part to be done. Some parts can't start until the middle of another part if they are depending on the results from an earlier stage. For example, if you are creating a book. You need to have the design and book done before you start printing it and before that you need to be sure that all the machinery is ready. Moreover, before you start selling the book you need to be sure that you have a high enough inventory to start selling it. The stages or activities which are dependent on each other are called linear or sequent. If it is not sequent nor linear it can be parallel tasks. This is when multiple stages of parts can run parallel to each other and not necessarily depending on any other parts. But dependencies therefore different standards.

The first is finished to start (FS) which means that activity 1 must be finished before activity 2 can start.

The second one is finished (FF) which means that activity one must be finished before activity 2 can finish.

The third one is started to finish (SF) which is that activity 2 cannot start before activity one has started.

The last one is started to start (SS) which means that activity one must start before activities two can start. After dependency that is another important factor which is leading like time, they are extremely crucial factors to account for when you have to look at a project schedule and how to manage the project schedule ^[10].

The simple way to explain lead time is that when activity b ,or two, starts when activity a or 1 is still running. An example could be that the first activity takes 50 days and activity 2 can start running when activity one is still running so maybe when activity one is halfway through. That would mean that activity 2 can start when activity one has reached 25 days meaning that the lead time for activity two is 25 days.

Lag time is when activity a is completed but there is a delay, so activity b does not start even though it's supposed to, this delay between the two activities is a lag. An example could be that activity ends on Monday the 21st 5:30 in the morning, but activity b only starts Monday the 21st at 7:00 that would mean there is a lack of time of one and a half hours ^[6]. So Step 2 is in short to see the relationship between two steps so to see if a step is parallel or secretly this is then with the new adjustment put into the Gantt Chart list with destroyed and estimated end date^[9].

Step 3: Put step 1 and 2 into a template or software

This step is where you draw you can charge either by hand or you specialised software. It is also possible to find some basic template for Microsoft Excel online. When starting to put in the different activities it's important to remember what you did in step one and Step 2 and combining them so that you have the correct order of when things are supposed to be done.

Step 4: Keep the Gantt chart updated

After making the Gantt chart and planning out the steps of the project and the project starts moving along the project manager will notice that there is often some delays this is that is why it is extremely important that the project manager keeps updating the chart so that the team which is a part of the project know what the next steps are, and went to start the next step so there's no lag time as mentioned in Step 2

The Critical Path Method

The critical path method was created by Morgan Walker and James Kelly junior in the late 1950s. Since then it has become widely used in different scheduling software and in other applications for the Gantt Charts ^[1]. Short describing or definition is that the critical path is the straightforward way of activities which are critical which need to have no lag because if they have any delays many other steps activities are depending on them and therefore if there's any lack in the critical path the project will run late.

A way to update or specify the Gantt Chart is to incorporate the critical path, for the specific project or phase. It is used to ensure the project does not fall behind, by identifying the most important tasks and often to find the tasks which are depending on one another and which will take the longest to complete. by incorporating the critical path which will be the different steps that will take the longest, or is the most important, you are able to schedule the rest of the project around the path to ensure that all the specific parts which are needed to finish the critical path are ready when needed^[1].

Delimitation

There are different delimitations when using Gantt Charts.

Firstly the Gantt Chart focuses on different activities happening over time and the relationships between the different activities. Sometimes it is extremely hard to know the exact relationship needed between different activities in the project process. The dependencies between different activities in order for there not to be any lag time, it is difficult to calculate but extremely crucial, and there might be delays in different places^[1].

The second limitation is that the Gantt Chart is only following one specific timeline. Which means that it cannot account for uncertainty in a project. And doing a project without any kind of changes is very unlikely.

The third is that the Gantt Chart does not take repeating into account and that not everything cannot take any other models in them.

If the Gantt Chart is not correctly controlled it can become very complex, since many people choose the Gantt Chart because of its simplicity it is extremely important that it stays simple. The reason complexity can emerge is that there can be extremely many tasks and steps to do, resources to control, and large numbers of employees. that is why it is important that the Gantt Chart is under monitoring all the time through a project so that the details are not missed, this could be a project manager's job.

There is no indication of the size of the job, the only thing which shows how difficult a job or task is is the time it takes to finish, but a task length is not always an indication of how much work needs to be put into the specific task. So if there is a new task which the employees have never done before they might not know how much work, time or effort it will take them, they will only have the date they need to be done with their specific task.

Then one is of course as mentioned before, the Gantt Chart is in need of constant updating, for every small detail. And often almost always when getting into a project there will be changes both small and big, and this can lead to complex problems or a later finish time. this is also often why there is buffer time in the project, and the bigger the project the bigger the buffer should be^[1].

Annotated bibliography

Ballesteros-Pérez, P., Larsen, G. D., & González-Cruz, M. C. (2018). Do projects really end late? On the shortcomings of the classical scheduling techniques. JOTSE: Journal of Technology and Science Education, 8(1), 17-33. This article looks into why some project is late, by definition a project needs to have an end date, but why is it that these dates are not always kept. They go into the reason often being poor project planning. Tt then goes into a critical review on classic scheduling methods, which includes the Gant Chart, The Critical Path Method, and Program Evaluation and Review Technique (PERT). and mention how and what each is used for and their limitation. It is an overall good insight into the classic scheduling methods and their limitations.

Petersen, P. B. (1991). The evolution of the Gantt chart and its relevance today. Journal of Managerial Issues, 131-155. This article by Petersen gives a good background on Henry L. Gantt and how and where he created the Gantt Chart, and how he got his knowledge as it mentions his schools and his different workplaces and what he worked with, and through Gantts experiences the steps to the creation of the Gantt Chart we know today. it also focuses on the evolution of the graphics when Gant created the Gantt Charts and his poplismennts.

references

1. ↑ ^{1.0 1.1 1.2 1.3 1.4} Ballesteros-Pérez, P., Larsen, G. D., & González-Cruz, M. C. (2018). Do projects really end late? On the shortcomings of the classical scheduling techniques. JOTSE: Journal of Technology and Science Education, 8(1), 17-33.
2. ↑ ^{2.0 2.1 2.2} : Petersen, P. B. (1991). The evolution of the Gantt chart and its relevance today. Journal of Managerial Issues, 131-155.
3. ↑ : James M. Qilson (2015). THE GANTT CHART AS AN AID TO PROGRESS CONTROL. THE INSTITUTION OF PRODUCTION ENGINEERS
4. ↑ : A. Swan (2003). Gantt charts: A centenary appreciation. SienceDirect
5. ↑ : D. Lock (2012). Managing aviation projects from concept to completion.
6. ↑ ^{6.0 6.1 6.2} : Debicki, Bart J. (2015). Forgotten contributions to scientific management: work and ideas of Karol Adamiecki.(pp. 40-67). Department of Management, Towson University, Towson, Maryland, USA
7. ↑ ^{7.0 7.1} Vel Rae Burkholde. (1983). Cost reduction program through the use of the Gantt chart Vel. North Dakota State Universety, College of Home Econurnics, Fargo, ND 58102 U.S.A. Introductio.
8. ↑ : Link to webpage with different Gantt Chart software. https://www.capterra.com/sem-compare/gantt-chart-software?gclid=CjwKCAiAg8OBBhA8EiwAlKw3kopXQ-4CCwXmUSzue2S7Mz0FnAa-FV_LL4O9cl0cdbz91vrlDVpmyxoCn00QAvD_BwE
9. ↑ ^{9.0 9.1} : Mind Tools Content Team (2020). http://www.mindtools.com/pages/article/newPPM_03.htm . Gantt Charts - Project Management Tools from MindTools.com
10. ↑ : Fahad Usmani (2020). Lead Time and Lag Time in Project Scheduling Network Diagram | PM Study Circle. PM Study Circle