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In the early 1900’s, Henry Gantt developed the Gantt chart, used all over the world to manage sequentially executed projects. To build a house, you dig the hole before you pour the foundation and you hang the sheetrock before you paint. There is a sequence to the process.

If you are developing a new product or a marketing campaign, or relocating your offices or installing a new computer system, there are often many different ways to execute the project.

The Gantt chart makes a flexible execution tedious, and so project managers wind up spending more time on managing than executing.

You should rethink using Gantt charts for business projects.

Note in the Gantt chart below that the lines look neat because the activities are going to be executed sequentially.


In the Gantt chart below the lines get all discombobulated when project activities aren’t executed sequentially.

After years of working with Gantt charts they can still give me a major headache.

While the excerpt below is a small piece of a relatively small project, printing this entire chart requires nine pages of paper. Then the pages are often taped together and hung on a wall.

I’m not the only person getting a headache from Gantt charts.

Gantt chart

Durations and Dependencies – Distinguishing “D’s” 

Construction is a well developed industry. Yes, things have obviously changed since the pyramids were built. Contractors are now generally pretty good at estimating how long it will take to pour the concrete or install wiring.

Contrast that with a new project to develop a new product that will store clean water for transport to third world countries.

The project manager is faced with activities which have never been done before. Estimating durations with any accuracy is often nearly impossible. When durations can’t be accurately estimated, the Gantt chart becomes meaningless.

In traditional project management, the key to developing a schedule is to identify dependencies. These are the links between activities. For example, concrete cannot be poured until the hole is dug. So, we say that pouring the concrete has a finish to start dependency on digging the hole.

Once the dependencies are entered, we let the computer automatically generate the schedule to achieve the most flexible execution.

However, if there aren’t many true dependencies, the Gantt chart is created with many activities starting on day one. We know that can’t work, so the project manager assigns artificial dependencies. As soon as that is done, we have an artificial schedule, and a project manager with a headache trying to manage to that schedule.

Alex Hornbake correctly referred to most project schedules as bogus in his blog post on rescuing failing projects.

While perhaps invaluable on construction projects, using Gantt charts on business projects is a waste of time. Durations are hard to estimate, dependencies are often artificial, and progress can’t be measured.

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Check out this video blog on developing more reliable project analytics and why Gantt charts don’t help.