What are Gantt charts, and how do they help you manage your projects? We have written an extensive article to show you the advantages of using Gantt charts in your projects.
These are the main points we will cover:
- What is a Gantt chart
- What are the components of a Gantt chart?
- The advantages and disadvantages of using Gantt charts
- How to create your own Gantt Chart
- With Excel
- What a Gantt chart looks like
- For creative and technical agencies
- For construction companies
What is a Gantt chart?
A Gantt chart is a useful tool for planning projects. By providing you with an overview of scheduled tasks, all parties involved will know which tasks need to be completed by what date.
A Gantt chart shows you:
- The start and end date of a project
- What tasks are within the project
- Who is working on each task
- The scheduled start and end date of the tasks
- An estimate of how long each task will take
- How the tasks overlap and/or if there is a relationship between the tasks
Components of a Gantt Chart
Typically, a Gantt chart contains the following elements:
- Dates: start and end dates allow project managers to have a view of when the entire project will start and end.
- Tasks: Projects consist of a series of subtasks. With a Gantt chart, you can keep track of these subtasks so that none are delayed or forgotten.
- Expected timelines: The diagram shows when each task should be completed. It will help you ensure that each subtask will be completed on schedule and that the entire project will be completed on time.
- Interdependent tasks: some tasks can be carried out at any time, while others must be completed before or after another task starts or finishes. These dependent tasks can be indicated in a Gantt chart.
- Progress: The diagram shows you exactly how your project is progressing by giving you a representation of the tasks that have already been completed. By indicating the current date, you get an overview of how much remains to be done and see whether everything is proceeding as planned to complete the project on time.
Advantages of a Gantt chart
Using a Gantt chart in your project management process provides you with the following advantages:
- A simplified overview
- Performance data
- Better time management
A Gantt chart breaks down multiple tasks and timelines into a single overview. This way, you know where your team is at each phase of the project. Use the diagram to show stakeholders how tasks are organized and what resources are allocated to each task. This way, you can clearly present to them where you are in the project and whether it will be completed successfully.
Teams use Gantt charts to replace meetings and status updates. This way, team members have a clear overview of the progress of each task.
By creating a clear overview, team members are more aware of their overall performance and will be able to adapt their work routine according to the needs of the project schedule. In addition, they will be more aware of interdependent tasks, and therefore better understand the impact of delays within the project. This type of planning encourages collaboration and better organization of tasks.
Gantt charts help you set realistic timelines. The bars on the diagram indicate in which period a certain task has to be completed. In this way, you make sure that you don’t undermine other projects that need more resources and time.
Projects often undergo changes. By having an overview of unexpected changes within a project’s objectives or timelines, you can adjust tasks and resources accordingly.
Disadvantages of Gantt charts
Projects that consist of a large number of tasks and resources can result in very complex Gantt charts, especially if you are working on a large project or have a very large team. Representing dozens or even hundreds of tasks on a Gantt chart can be confusing or difficult to read. Therefore, it is critical to assess the different tasks and subtasks before making the chart and assign someone to keep track of the details.
For a Gantt chart to be effective you must plan your project in a linear fashion from start to finish. So you must know the outcome and the steps leading to that outcome before you start. This may sound obvious enough when building a house, for example, but it is much more complicated when it comes to web developers working on a project where the client has not specified the end result.
As we mentioned before, projects change. If you are going to use a Gantt chart, you have to adapt it accordingly. The responsible project manager has to update the chart frequently, although this task can be simplified with the help of a project management program.
How to create a Gantt chart?
To create your first Gantt chart, follow the process below:
- Make a list of all tasks
- Make a list of all interdependent tasks
- Create a project timeline
- Assign tasks to team members
Make a list of all tasks
Write down all tasks that need to be completed to successfully complete the project. You should also include deadlines and responsible team members.
For example, if you are redesigning a website, a large “activity” would include creating a series of Photoshop mockups.
In turn, this activity can be broken down into several tasks:
- Create wireframes
- Review the usability performance of the wireframes
- Create mockups with the best performing wireframes
- Create a prototype from the mockup
- Perform usability tests
- Review and authorize the best performing prototypes to move to development
This same process can be applied to other types of projects, such as building a house. In this case, the tasks can be subdivided as follows:
- Order materials
- Send a partial invoice
- Install the floor
- Paint the walls
- Invoice the hours worked
Make a list of all interdependent tasks
Often, you have to finish one task in order to start the next one on the list. Let’s compare it to a dinner party with friends: first, you have to cook dinner (Task A), and then you can serve the food to your guests (Task B). There are other tasks that can be done at the same time. You can cut the vegetables (Task A) without having to wait for the potatoes to finish cooking (Task B). Plan how the different tasks related to each other in your project.
Create a project timeline
How many days or even how many hours does this project need? Keep in mind that all projects tend to experience delays: take a look at the historical records of past projects and track time consistently to get an idea of how flexible you will need to be in creating your timeline.
Assign tasks to team members
In this case, it will also be helpful to have historical records of individual results. For example, if your data shows you that a particular member tends to turn in tasks late, you can avoid assigning them higher priority tasks or give them more attention so that they turn them in on time.
You will also need to consider:
- What other projects your colleagues are working on simultaneously.
- The scheduled breaks or vacations of team members.
How to create Gantt charts in Excel
Step 1: Make a list of all tasks with their start and end dates.
If you have completed all the above steps, you will now have an overview of:
- The names of the tasks
- The start dates of the tasks
- The duration to complete the tasks
Start creating a new spreadsheet with Excel and write down all the tasks along with their start and end dates.
Step 2: Calculate the start day of each task.
Add a column titled “Start day”. Convert the start date to an integer with the int () function. Calculate the start day by subtracting the task start date from the project start date.
In this case, the formula for the first task would be as follows:
Note: You have to add $B$2, instead of B2, to determine the absolute position of cell B2 in the formula.
As a result, the column should look like this:
Now you know which day each task has to start.
Step 3: Calculate the end day of each task
Subtract the start day of the first task from the end date of the current task using the following formula:
Step 4: Calculate how long each task will take
Subtract the end day from the start day with this simple formula:
Now you have in your hand all the data you need to create a Gantt chart.
Step 5: Add a chart
Select the following data columns in your spreadsheet:
- Task name
- Start day
- Task duration
Once selected, click Insert > Diagram and select “Stacked bar chart”.
Select the first series of (“Start Day”) in the chart. Change the color to “None” in the pop-up menu.
Once you have changed the color, your diagram should look like this:
Congratulations! You have just created your first Gantt chart.
Note that this diagram has some limitations.
- There is no easy way to assign tasks.
- You cannot make changes quickly and easily
- You do not have a clear overview of interdependent tasks.
For larger projects, it may be a good idea to use project management software with Gantt charts included.
Gantt charts in practice
Wondering how you can apply a Gantt chart to your business? In the following examples we will describe how agencies and building companies can get more out of this tool to improve their project management.
Gantt charts for agencies
Although there is a big difference between creative agencies and IT agencies, both share several important aspects of project management:
- Both depend on the desires (sometimes rapidly changing) of many stakeholders.
- To meet the expectations of everyone involved, projects are often delayed and the budget needs to be increased.
- There are numerous tasks that can be performed simultaneously, and also other tasks that need to be completed first in order to start the next one.
Detail your desired timeline so you can manage your clients’ expectations from the start. Involve all team members in the creation process and update your timeline as soon as a meeting or task changes.
If you’re developing a website, for example, you’ll likely use a preset process like the following:
- Develop UI wireframes
- Create mockups in Photoshop
- Develop website
- Test website
In this process, there are interdependent tasks. Designers must create wireframes before developers can start working on the website, which cannot be tested until a raw product is available.
There is also the possibility that different steps may have to be repeated before each task is completed. Designers may have to make different mockups until the client is completely satisfied, for example. All these tasks can be tracked using a Gantt chart.
One industry where Gantt charts are especially useful is the building industry. Managing a construction project is very different from the above because the individual tasks are highly interdependent. You can’t start building the roof if you don’t yet have the columns. And you can’t start laying the bathroom floor until the roof is ready.
On the other hand, in construction projects the hours worked are easy to compute. A mason is able, as much as possible, to lay the same number of bricks per day.
By being able to easily compute these hours, the Gantt chart will help you estimate project dates.
How to start creating your own Gantt chart
If you’re working on larger projects, it’s a good idea to take a look at different project management tools. Although you can always help yourself with our tips for creating a Gantt chart in Excel. Anyway, now you know everything there is to know about Gantt charts.
They are very useful to have an overview of all your tasks and their estimated start and end dates. They help you see how to organize tasks and resources, and how each member of your team is completing each task. It is also an effective tool to simplify communication and give you an idea of your overall performance.
Frequently asked questions about Gantt charts
We have dedicated the following section to answering the most frequently asked questions about Gantt charts.
What is a critical path method for?
A Critical Path Analysis (CPA) is a fundamental technique for managing projects. It helps you identify which activities need to be completed for each task, including the time required to complete each activity and the relationship between these activities. The critical path method allows you to forecast whether a project can be delivered on time.
What is free float or free float project management?
The free float is the amount of time a task can be delayed without causing a delay to the next task within the project.
What is the work breakdown structure in project management?
In project management, the work breakdown structure or WBS is a hierarchical breakdown of an entire project into smaller components. It helps you understand the end goal of a project and organize the team’s work by breaking the project into more manageable sections.
What are PERT diagrams?
PERT stands for Program (or Project) Review and Evaluation Techniques. Originally developed by the U.S. Department of Defense in the 1950s to help manage the Polaris project, PERT is a method for identifying the minimum time required to complete a project, as well as incorporating the uncertainty factor.
What is total float or total project management float?
The total float is the amount of time a task can be delayed without causing a delay in the project delivery date.
What is the negative float of a task?
The negative float (or negative slack) is the amount of time required to complete a task beyond the initially scheduled delivery date. In other words, the negative float is the amount of time that must be made up in order to deliver the project on time.
Why is it called a Gantt chart? Who was Gantt?
The Gantt chart was named after its inventor, Henry Laurence Gantt (1861-1919), an American engineer and management consultant. The Gantt charts he invented were used for major infrastructure projects, such as the Hoover Dam or for the Interstate Highway System, and, today, it remains an important project management tool.
What does “project scheduling” mean?
Project scheduling is a methodology for communicating what tasks need to be accomplished, and what resources will be allocated to complete those tasks in a given time frame.