Modern projects can span anywhere from several weeks, months, quarters, or even years. In this time, there will likely be numerous tasks and deliverables that the team needs to accomplish. It is vital for a project team to track every task over the course of a project to ensure that they’re making the right adjustments to meet their deadlines and achieve their goals.
To make tracking a project’s overall progress more convenient, a team can employ the use of a Gantt chart, a time-tested project management tool that’s been used for over a century. In this article, we’ll be taking a deeper look at Gantt charts and why they’re still used to this day.
A Gantt chart is a tool that helps project managers and their teams visually track the progress and completion of each task within a project. Its main purpose is to provide an overview of a project’s various deliverables on a timeline, indicate what it’s Planned Start and Finish dates are, and track how long it takes for a task to be actually completed (with the Actual Start and Actual Finish dates). Gantt charts visualize this information, and in turn help project managers make informed decisions regarding adjustments to the project team.
The Gantt chart is named after an American mechanical engineer and management consultant, Henry Gantt. Gantt had the idea to use charts to track the progress of projects. A key distinction between the first Gantt charts and their modern iteration is that the first ones used full bars instead of boxes. While this allowed him to use Gantt charts much like we do today, they had to be redrawn completely after every change. This made original Gantt charts unwieldy and time-consuming to use, in spite of their benefits.
Sometime after Gantt’s passing in 1915, Gantt charts were changed to be more efficient to use. Teams started using blocks, shading them over the course of the project rather than drawing and shading a full bar. This change also meant that the charts no longer had to be completely redrawn after minor adjustments.
When personal computers and the internet started becoming more accessible, Gantt charts, as well as other project management tools, began shifting away from physical charts to digital versions. Today, Gantt charts are used almost exclusively through software applications.
While different teams may have their own unique takes on Gantt charts, the modern Gantt chart can be broken down into three key components: tasks, timeline, and progress bars.
The left of the Gantt chart is the list of tasks to be done to successfully execute the project. This should be arranged from top to bottom, starting with the first task to be done, followed by any succeeding tasks, then culminating with the final one.
While there can be concurrent tasks that begin at the same time (usually at the start of the project), dependent tasks are typically organized chronologically to keep things organized and easily understood at a glance.
Typically, the top or bottom of the Gantt chart denotes how long a project lasts. These parts of the chart are usually labeled by days or weeks, depending on how long the project’s overall duration is.
Each of these days or weeks is represented by a block, which is then shaded depending on whether the corresponding task was being completed during that time. For example, if a task takes three days to complete, it will take three shaded blocks on the Gantt chart. These blocks are what make Gantt chart a useful tool for tracking not just how long a task is being worked on, but from when and until when it was being worked on as well.
Gantt chart progress bars also have “planned” and “actual” parts to each bar. This can help teams compare their planned estimates to how things are actually going in the execution phase. This can help teams identify what unforeseen problems they faced during execution that were not accounted for during the planning phase–and strategize means to remedy these issues.
When there are dependencies between two tasks, the predecessor’s bar would end right where the following task begins. This feature of Gantt charts is what allows teams to track dependencies relative to the progress of their preceding tasks.
Where are Gantt charts used?
Gantt Charts are, by their very design, predictive and are best suited for projects where many requirements such as timeline and scope are already declared upfront. A Gantt chart is supposed to be able to track the progress of a project’s various tasks within a given time frame, such as three weeks or a quarter.
This makes Gantt charts the preferred method of progress tracking for traditional project management and industries that utilize such methodologies, such as manufacturing and construction.
When it comes to Agile projects, Gantt charts take a different role. Not every Agile project begins with a specific timeframe, as some projects can begin without the team knowing how many weeks or months it will take to complete–or even be supported after a given time. This makes plotting out the tasks of an Agile project onto a Gantt chart almost impossible.
Instead, Gantt charts are used at a higher-level, managing multiple smaller Agile projects and their key milestones rather than tracking individual tasks. Similarly, there are situations where a team should and shouldn’t use a Gantt chart–which we can identify by looking at their advantages and limitations.
High-level view of a project and its timeline
Another key benefit that Gantt charts provide is they provide clarity on how various tasks are related and dependent on each other. While dependencies can easily be managed individually, it becomes much more complicated when managing dozens upon dozens of them within a project.
A Gantt chart gives project managers a visualization of these dependencies which then enables them to strategize the most optimal flow of work. By doing so, the project manager increases the team’s chances of success.
Clear view of progress and deadlines
As an overview of an overall project, Gantt charts can be used to provide information both within a project team and with external stakeholders.
Internally, this helps the team stay on the same page by keeping track of how the project is progressing. This helps teams understand the progress on their current task, and how much left they must do, as well as monitoring the progress of their any concurrent tasks.
Externally, Gantt charts can be used to provide updates to stakeholders. As higher-level stakeholders tend to not be overly involved in projects, comprehensive yet simple to understand visualization tools, such as Gantt charts, can be helpful in providing important information. Additionally, Gantt charts can also be used to help set expectations and deadlines with the project’s stakeholders.
They work best when the plan is clearly defined
Gantt charts only show time elapsed
Gantt charts tell a story, but alone, they don’t tell the whole story. As the purpose of a Gantt chart is to show how much time has been spent on specific tasks, other information such as amount of work required as well as costs incurred aren’t part of what a Gantt chart is supposed to show.
While the length of a task’s progress bar may be indicative of the amount of resources used for it, this isn’t always the case. At times, a task can have a relatively short progress bar spanning only one or two blocks while still being costly. Other times, a task can span days or weeks yet require only minimal resources. In this regard, Gantt charts are inherently flawed.
Difficult to use in large-scale projects
To summarize, Gantt charts are a great tracking tool for when project teams need a simple visualization for how their project is progressing. Teams should use a Gantt chart when they are delivering projects using traditional project management methodologies, such as Waterfall, as these would provide all the information necessary for them to be created.
The bird’s eye perspective can also be invaluable for both project teams and their stakeholders. It allows anyone to see how a project is progressing, and if there are any adjustments that can be made to improve the overall delivery of the project.
The Gantt chart is not the be-all-end-all of project management tools–in fact, there is no such thing. However, it is still a valuable tool that every project manager should know how to use. Most project managers, and especially executives, still like to have a “timeline view” of where a project and its tasks are in terms of timeline and completion status. Whether it is a full program or project, or a product Release or a Program Increment (PI) in a scaled agile context, people would like to see a timeline view – essentially a Gantt view of both the high level phases/ tracks as well as the detailed tasks, milestones and dependencies.
