How to Save the World Using Gantt Charts

By Jon Miller Updated on May 3rd, 2021

There are many tools available to project managers for coordinating work and keeping their projects on schedule. Small and simple projects may use task lists or spreadsheets to track the status of work items. Teams working on longer term or more complex tasks often benefit from visualizing the progress of tasks in a shared space. One such example is the Kanban board used to enable Agile practices. Today, there are many online platforms that combine visualization in a virtual space with the benefit of file sharing and real-time collaboration.

What Is a Gantt Chart?

On the other extreme is the Gantt chart, a classic pencil-and-paper method for visualizing the work breakdown structure in routine industrial operations. This project management tool is useful for planning, scheduling, and executing complex projects in construction, marketing campaigns, design and creative, manufacturing, software development, event planning, and so forth.

A well-constructed Gantt chart helps team members see and answer many important questions. Do we have a plan that will meet the deadline? What needs to happen first? What activities must be completed to get from point A to point B? Are we currently on track to meet the deadline?

It’s somewhat surprising that such a well-established and useful project visualization tool doesn’t get more appreciation in lean, Agile, and continuous improvement circles.

Why Don’t Gantt Charts Get More Respect in Lean Circles?

A very basic reason may be that at a glance, Gantt charts appear quite complicated to build, read, and update. The more complex and multi-faceted a project is, the more this is true. Taking the time to visualize this complexity often helps to make it simpler, or to identify potential pitfalls. But it does require learning how to create a new tool. When software is seen as the way to create Gantt charts, rather than by hand, this can add another layer of friction to learners.

Another reason that Gantt charts don’t get their due respect in lean circles may be because there is a bias for small and quick changes. For instance, the Toyota Kata approach assumes that there are too many uncertainties and unknowns to achieve a specific challenge. This requires many iterations of experimentation and learning. The view is that making detailed improvement plans and trying to execute them is not sensible, since plans are bound to change a lot.

The Agile Kanban approach discourages making detailed project plans because of the belief that that low WIP, speed, and adaptiveness contribute to success more than adherence to the project plan. Similar to kata, this is also rooted in the assumption that the unpredictability and instability of development work can’t be planned out in advance.

The classic kaizen event avoids the need for Gantt charts by narrowing the scope, doing upfront preparation to remove many uncertainties, and focusing the resources to make rapid changes across a week or two. On the other hand, Gantt charts are handy for larger scale lean projects such as plant layout, value stream redesign, or launching trainings or new management practices.

Lean Gantt Charts Hidden in Plain Sight

Gantt charts break a project down into tasks and visualize start and end dates so that we can manage firm deadlines. These charts help multiple people work on interrelated tasks in a specific order in a coordinated way. The real power of Gantt charts in the context of continuous improvement is the ability to see dependencies between tasks and identify the critical path. The critical path is the sequence of events that requires the minimum time to complete an operation. There are several lean tools that make good use of this principle.

The standardized work combination sheet is basically a one-person Gantt chart. It shows the work of a person for a repetitive cycle. There is a firm deadline, the takt time. The individual task times are known. The work sequence is specified. The dependencies take the form of standard WIP which must be there and ready for the worker to pick and replace each cycle.

The SMED technique of tag teaming the internal time of a quick changeover is another example. If 10 minutes of downtime on a critical asset can be cut in half or even by a third, it’s often worth having two or more people work together. The pit crew in NASCAR racing is an example of this idea taken to an extreme.

When mapping a value stream in order to reduce lead-time, the large first-in first-out queues and blocks of WIP represent opportunities to shorten the critical path. On a much smaller scale, the bar chart to balance the cycle times of multiple operators to takt time also reveals dependencies and the proverbial longest pole in the tent.

How Gantt Charts Are Saving the World

Source: Clinical trial medians from “Development Times and Approval Success Rates for Drugs to Treat Infectious Diseases”

Around a year ago, the world began to accept that we were in a pandemic. We soon wondered, “When will it be over?” Typical vaccine development takes years, we were told. Here is a critical path diagram of all activities required to complete development of vaccines. There are nine major activities from academic research, to pre-clinical, three phases, to building production lines, to the vaccines’ manufacturing, approval, and distribution. Traditionally, each activity is completed in series, one before the next begins.


Source: “What’s Going On in This Graph? | Estimated Time for Covid-19 Vaccine”, Wall Street Journal

Nobody thought that was good enough. Fortunately, there were some smart people familiar with Gantt charts and their underlying project management principles. They looked at activities that could be done in parallel. They identified where we could take intelligent risks, and where to spend massive resources to reduce the timeline. Smart people estimated that we would have a COVID-19 vaccine by August 2021.

Half a year from that date, today we have multiple vaccines in use. Several of them took less than 8 months from ideas to shots in arms. It makes you wonder what else is possible if we all agreed it’s important, mapped it out on a Gantt chart, and got down to work.



  1. Gustavo Mendoza

    June 16, 2021 - 3:11 pm

    Completely agree with this content. But, why people stop uses Gantt Charts?

  2. alhussain abushady

    June 17, 2021 - 1:38 am

    I am very happy to look at this topic, especially ganttchart, and learn more of this valuable information.

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