Do you know Gantt chart? You may have heard the name, but don’t know the details.
Gantt charts are used to manage project schedules and progress charts in a wide variety of fields, including web service development, construction sites, and manufacturing.
This time, we will explain the basic knowledge of Gantt charts, explain how to make them, and introduce free Excel and spreadsheet templates.
What is a Gantt chart?
A Gantt chart is a diagram (process chart, progress chart) used primarily to manage work processes and progress in projects. A typical Gantt chart shows the person in charge and start date and completion date on the vertical axis, and the progress rate and date and time on the horizontal axis.
In addition, by showing the work period and progress of each task as a horizontal Gantt bar, you can understand the project timeline at a glance. The structure is similar to a schedule management table.
The Gantt chart was invented by American management consultant Henry Gantt during World War I. The name Gantt chart is derived from his name.
The Gantt chart was made known around the world by Wallace Clark’s book The Gantt Chart: A Working Tool of Management, which was published after Gantt’s death.
Currently, it is used in many industries and industries, and is said to be an indispensable tool for project management.
Difference between Gantt chart and WBS (Work Breakdown Structure)
Gantt charts and
WBS (Work Breakdown Structure)
are often used together, so they can be confused, but they are different.
Gantt charts are created to share work details and progress among all members.
A WBS is created to ensure that no work is left out in the Gantt chart.
In other words, a “WBS” is a list that breaks down the work details of a project, and a “Gantt chart” is a table created using it.
Advantages of Gantt chart
Gantt charts have many advantages, which I will explain below.
Entire project can be visualized
The biggest benefit of using a Gantt chart is the visualization of the entire project. By assigning people, due dates, and tasks to the Gantt chart, you can see the following items at a glance:
This makes it easier to make decisions about staffing and schedule adjustments. Even after a project has started, being able to visually see the progress and who is in charge of tasks in real time can improve work efficiency. Additionally, since the information is all in one place, there is no need to search for information or manage it individually.
Facilitating projects through information sharing
By using a Gantt chart, the work contents and progress status of the entire project, due dates, and persons in charge are shared. In other words, you can understand the overall schedule, including which work should be completed by whom, by when, and the current progress of the work.
Since a large number of people are often involved in a project, being able to share the overall situation in an easy-to-understand manner is an advantage.
In addition, the Gantt chart allows you to see the burden on individual team members and variations in progress, allowing you to proceed with the project according to the situation. Even if there are changes to your schedule or tasks, you can share them with your members using a Gantt chart.
Able to respond quickly in case of project delays
I think it is rare for any project to go according to plan and be completed.
In a project, it is expected that work delays due to problems or tasks may be reassigned due to unexpected events.
Even if such a problem occurs, the Gantt chart allows you to check the progress in real time, allowing you to respond quickly.
Another good thing about Gantt charts is that even if there is a delay in the schedule, you can take immediate action.
Disadvantages of Gantt chart
Of course, there are not only advantages but also disadvantages.
Difficult to understand man-hours
The disadvantage of Gantt charts is that it is difficult to understand the amount of work required for each task. The man-hours for each task are not listed on the Gantt chart.
As a result, there are cases where the number of man-hours required to complete the work exceeds expectations. As a result, they are unable to meet the scheduled deadline, causing confusion on site.
If one task is delayed, it rarely affects the overall schedule, so it can have a bearing on the success or failure of the project itself.
If you create a Gantt chart by counting backwards from the delivery date, you will tend to end up with a schedule that does not have enough leeway, resulting in a situation where the number of man-hours is not spent after the project starts.
It is difficult to see which tasks should be prioritized, making it difficult for problems to surface.
Gantt charts have a simple and easy-to-understand structure because their main purpose is to share schedules. On the other hand, since the only information available is the task content and due date, it has the disadvantage that the order and relationships between tasks cannot be seen. Therefore, it has the disadvantage that it is difficult to understand which tasks should be prioritized.
Furthermore, if we are not conscious of it, we tend to work on tasks in order of deadline, starting with the deadline, and when we have time to spare before the deadline, we tend to put things off until later.
Also, because you are so focused on your own tasks, it is difficult for you to notice problems until they occur, and it is often too late.
It lacks flexibility and takes time to reassemble the Gantt chart.
Reassembling a Gantt chart takes time. Also, the more changes and updates to the plan, the more likely it is that omissions will occur.
In that case, you will have to start over by examining the Gantt chart itself, which will require you to spend time and effort.
Therefore, Gantt charts are not suitable for projects where plans and tasks may change frequently.
Gantt chart basic terms
Introducing commonly used terms in Gantt charts. It is a good idea to understand these terms as they are important when creating a Gantt chart.
How to make a Gantt chart
Now that you understand the basic Gantt chart, let’s explain how to create one. There are four main steps to create a Gantt chart. I will explain them in order.
Identify tasks and create WBS
First, identify tasks and create a WBS. The trick when identifying tasks is to write down the largest item in your work framework.
From there, each task is broken down to the point where the overall picture of the project can be shared among the members. Please be careful not to make it too detailed as progress management will be difficult.
With Gantt charts, if the quality of the WBS is poor, the project will fail.
This item is arguably the most important, so take your time and create it carefully.
Estimate work time for each task and determine work schedule
Next, estimate the amount of time each task will take and decide on a start and end date for each task. The key point here is to carefully examine the relationship between tasks and create an optimal work plan.By clarifying work dependencies, you can take into account troubles and allow enough time for each task to work.
Also, set milestones and critical paths to clarify important parts of the entire project.
Enter into Gantt chart
Enter using a Gantt chart creation tool, Excel, or spreadsheet.
Often, the vertical axis shows the task, its person in charge, start date and completion date, and the horizontal axis shows the date and time. As I will explain later, there are free templates for Excel and spreadsheets, so you can use them to create them efficiently.
You can also make it easier to see the progress by using different shapes and colors, such as arrows, on the horizontal axis. After entering the information, check that you have not forgotten to enter any tasks and that you can see the work dependencies.
Determining the person in charge
Finally, decide who will be in charge of each task and write them down. Be aware of distributing the people in charge of each task.
If the proportion of a particular person in charge is large, the impact on the project will be greater in the unlikely event of an illness or the like.
It is also necessary to consider the burden on the person in charge of the task. A Gantt chart does not show the difficulty level of a task or the skills required. Be careful, as the strengths and weaknesses vary depending on the person in charge.
Keeping these things in mind, we clarify the scope of work and roles of each person, and assign tasks to individuals and teams to complete the project. After filling in the person in charge, share it among the members and prepare for the start of the project.
Points to remember when using a Gantt chart
There are several points to keep in mind when using a Gantt chart. That is the following item.
Identification of work
Before using a Gantt chart, it is necessary to “identify the work”. The Gantt chart has “work items” on the vertical axis and “period” on the horizontal axis, and it is necessary to “identify the work” in order to set the work items on the vertical axis.
The work items on the vertical axis can be derived by creating a work breakdown diagram using a method called “WBS = work breakdown structure.”
What is “WBS = work breakdown structure”?
WBS is a method of organizing the entire project hierarchically, and when translated directly into Japanese, it is “work breakdown diagram” or “work breakdown diagram.”
In other words, “work” is “breakdown” and “structure” is created. By breaking down and structuring the work, you can visualize the work content of the entire project and understand the work volume.
By being able to see the entire project in this way, you can estimate the man-hours and make it easier to manage.
Create a chart in anticipation of corrections
After creating a Gantt chart, you may be forced to review the work content, man-hours, or change the schedule due to changes in specifications.
In these cases, it’s best to avoid creating a chart with too much detail so that you can quickly write in or add changes.
After all, simplicity is best, and since it is easier to make changes and corrections, it is also effective from a time performance (time performance) perspective.
Clarification of relationships between tasks
In order to efficiently progress a project using a Gantt chart, it is necessary to clarify and understand the relationships between tasks.
For example, in order to start work B listed on a Gantt chart, work B may not be possible unless the previous work A has been completed. We understand the critical path to clarify the relationship between these tasks.
By clearly indicating this critical path in a Gantt chart, you can prioritize tasks and clarify which tasks should be started first.
What is critical path?
Critical path literally means “important route” and refers to the work route that affects the schedule throughout the project.
In other words, if progress on the critical path is delayed, the entire project will be delayed.
By understanding the critical path when creating a Gantt chart, you can proactively reduce the risk of project delays.
How to find the critical path
One way to find the critical path is to create an arrow diagram. Also known as a PERT diagram (Program Evaluation and Review Technique), it is a flowchart diagram of the entire project that takes into account the required period and time required for the work.
Since you can visualize the divided work processes, required period, and time required for the entire project, you will be able to understand the process chart that is a bottleneck in the work, and manage tasks that can be performed in parallel. .
Share it the way you like it
It is important to be able to share Gantt charts with your team. Even if only managers are aware of the project, work cannot proceed efficiently.
To achieve this, we recommend operating a shared server or using the cloud for centralized management.
By viewing and referencing the same data as a team, it also helps prevent discrepancies between members. It is also effective in the sense that the team works together to complete the task and share the same goal.
Free Gantt chart template
There are many specialized tools for Gantt charts, but the drawbacks are that they are expensive to use and it takes time to get used to them.
Gantt charts can also be created for free using Excel or spreadsheets, making them easy to use and used by many companies.
Here we will explain Gantt chart templates for Excel and spreadsheets.
Gantt chart template in Excel
Creating a Gantt chart from scratch can be difficult, so we recommend downloading a template.
You can download Gantt charts in Excel files for free from Microsoft’s
official page
.
Basic items such as tasks and people in charge are already entered, so you can save a lot of time creating them.
Also, if you search for “Excel Gantt chart template”, you will find many other Gantt chart templates, so you can check them out and find the one that suits your needs.
Gantt chart template using spreadsheet
Google Spreadsheet templates are also available to anyone with a Google account. Basic information is entered here as well, just like in Excel. The steps to obtain the template are as follows.
1. Log in to your Google account
2. Select Spreadsheet from the Google app on the top right of the screen
3. Click on the template gallery and select Gantt Chart from Project Management
4. The Gantt chart template will open and you can freely edit it.
Also, with spreadsheets, you can set editing permissions and shared members, so it’s a good idea to decide permissions depending on how you interact with the project.
The setting method is as follows.
1. Open the Gantt chart and select Share on the top right
2. “Share with people or groups” and “Get link” screens are displayed.
3. Enter the email address of the person you want to share in “Share with people or groups”
4. Set the permissions for “editor” or “viewer” and press send.
5. Press copy link to the right of “Get link” and tell the URL
Timeline View
You can create your own original Gantt chart by using the timeline view. Below we will explain how to create a Gantt chart using the timeline view.
What is Timeline View?
In November 2022, Google announced the introduction of new features to Google Sheets. That is “Timeline View”.
You can interactively manage and track projects and tasks on Google Sheets. This new feature is expected to deepen collaboration between teams.
What you can do with timeline view
If you make good use of the timeline view, you will be able to visualize information in project management, making various management easier.
Create a timeline view
1. To create a timeline view, first create the source data. This time, prepare the “task name”, “start date/end date”, “overview”, and “person in charge” and enter them into Google Spreadsheet as follows.
2. Next, click “Insert” from the menu and click “Timeline” from the pull-down menu.
3. The “Create Timeline” pop-up screen will be displayed, so specify the data range selection and click OK.
4.A separate sheet with a timeline view will be added to the same file.
How to create a Gantt chart using the timeline view function
You can easily create a Gantt chart from your to-do list.
The items displayed on the task card reflect the following information.
If you want to add a new item, you can do so from “Card Details”. You can also categorize tasks using “Card grouping”.
Industries that are compatible with Gantt charts
So far, we have explained the meaning and how to create a Gantt chart. Gantt charts are often used in the IT, event, and construction industries. I would like to explain this using web production in the IT industry as an example.
When creating a website, it must be completed by the release date, so schedule management is very important.
Therefore, we begin by identifying the necessary task meetings, design production, final tests, etc., and calculating the number of man-hours required.
Also, don’t forget to leave some leeway in your schedule in case of unforeseen circumstances.
Once we have calculated the man-hours, we assign each task to the person in charge and share the overall website production schedule with all members. Then we start creating the website.
This is a simple description of the flow, and it is similar to the process chart for creating a Gantt chart. You can also see that it is compatible with the Gantt chart’s benefits of visualizing the entire schedule project and sharing information.
Due to this background, Gantt charts are used in website production sites.
summary
Finally, I will summarize what has been covered so far.
By making good use of Gantt charts, project management can proceed smoothly. Why not try using some of the free templates as a reference?