A Gantt Chart Alternative – Gantt Box Chart

Posted on July 9th, 2010 in Charts and Graphs - 14 comments

Have you ever worked on a project which has a plan? What is your experience like?

Let me tell you what my experience is like:

The project plan was changed dozens of times. Delivery dates, shipping dates, testing dates or any other important milestones were constantly revised, sometimes until the last week. Uncertainty seemed to be the biggest problem project managers spent their time on. My managers worked hard to avoid unpleasant surprises.

And this is where the ubiquitous gantt charts often fail.

In real world, the end date for each project activity depends on various factors like productivity, progress of other tasks, extra work, employee mood etc.. Thus, the end dates are best expressed in a format like {best case, realistic case, worst case} instead of just one date.

So I am boldly proposing a new type of project plan, henceforth to be called as,

…wait for it…

Gantt Box Chart

Think of Gantt Box Chart as a holy matrimony between Gantt Chart with Box Plot. The Gantt Box Chart shows uncertainty in project activity end dates by clearly showing 3 end-dates instead of one in the familiar box plot format. The end dates (best case, realistic or plan and worst case) are encoded as a box while the start date is shown as a dot.

Here is how a Gantt Box Chart looks like:

Gantt Box Chart - An Alternative to Traditional Gantt Chart based Project Plans

Despite the ugly name, I think the chart is very useful because,

  • It shows the uncertainty in plan, very clearly
  • It is as easy to read since we follow the Box Plot protocol
  • It lets manager focus on the most uncertain portions of project, quickly
  • It is new, so the chances of it getting neglected by everyone in boardroom are less 😀

I have summarized few additional observations you can get from a Gantt Box Chart here:

Gantt Box Chart - Additional Observations and uses

How to make a Gantt Box Chart in Excel?

I will be showing a way to create the gantt box charts in excel on Monday (12th July). Meanwhile, feel free to discuss this new chart and share what you think.

What do you think about Gantt Box Chart?

Would you use Gantt Box Chart for your next project or is this a little too much? What do you think about my proposal? Please share using comments.

Related: Project Management using Excel – an extensive collection of resources, templates, tutorials and ideas for project managers using excel.

Written by Chandoo
Tags: , , , , , ,
Home: Chandoo.org Main Page
? Doubt: Ask an Excel Question

14 Responses to “A Gantt Chart Alternative – Gantt Box Chart”

  1. Kenjin says:

    That's a great idea.
    Maybe the planned End Date should be highlight more.
    I don't know how it would look like (nor how to do it yet), but what if instead of finishing the bold line to the best case End Date, it finishes to the realistic End Date?

  2. ross says:

    The idea is ok, I think other project management tools have this, already? Maybe not.

    Gantt charts in my view are about the signal most unless thing in the world, theres no way you can look at one thats more that a little complex and understand what it's telling you. I'm going to write a diatribe on project management at some point, its one of my pet areas I think!! 😉

    The issue I have with this chart Chandoo, is that Tasks need to be linked to each other, so they should inherit the uncertainty, which would mean the as you moved down chart the lines would be miles apart for later tasks, and you might have to add lots of lines for subsequent tasks to cover the various outcome of it's parents.

    Having said that, for the high level board summary, it's a nice way to go, it it appeals to the management 😉

    thanks Chandoo, great post.

    Ross

  3. Cyril Z. says:

    Whoooa !!! That's a very clever idea Chandoo. I really love it.
    I think i'll update my gantt project sheet with that idea soon (remember my template ?)
    @ross : you can link start date to the end date of the previous task in your data. The only problem I still se is to which end date (real ? planned ? best ?) in order to have average amount of information.

    If best end date, you'll tend to increase uncertainty at the end of chain, although if you link to real end date, uncertainty will be decreased too much, leading in both cases to wrong management direction.

    Maybe planned till the task is finished then real will do the job ?

  4. Vijesh says:

    Hey chandoo, this looks good and this would definite add value in production planning / scheduling. Uncertainity in finishing a task is very high in production scheduling and this could give an insight or a bird eye view of possible shipments we can have....

  5. PK says:

    I've always been frustrated by the limitations of gantt charts. Will definitely use this, I've always struggled with how to succinctly communicate the uncertainty of certain tasks without confusing stakeholders.

  6. Andy says:

    I like this, I think it's a very effective way of showing how a timeline can change and which parts of a project need close attention.
    @Cyril / @Ross: I would intially link the the start date to the planned end date of the previous task, with the chart updating when a task has been completed to reflect the true end date.

    Or what about giving a drop-down selection box to allow the user to see the chart based on planned/best-case/worst-case end dates?

  7. Eric says:

    Like the idea. Have found that Excel is more flexible than MS Project for graphical solutions. The "Best Case"\"Worst Case" metrics are theoretically appealing but once the project and\or phase commences their reliability diminishes. A chart like the above that showed Planned Start, Planned End, Replan End Start, Replan End Date, Number of Replans the Start and End Dates, and Actual would provide an active, actionable view of each task\phase. It would also highlight the areas which are riskiest.

  8. Bob says:

    It is always amazing how flexible excel can be.

    My question is how would the chart show a scenario where the date moved up? If a task is dropped or the duration of the task is significantly reduced by applying more people or machinery to the task, the dates will move up.

    The gantt chart has been around for a long time, but it is still quite useful to show progress.

    Cheers,
    B

  9. Shyam says:

    I like the idea but seems bit complicated in case of long projects involving numerous activity.

    Also, reading and explaining is required hence not feasible where plans are just send to audience for approval.

    Cheers
    SY

  10. Peter says:

    Great idea Chandoo,

    When I was reading this idea regarding delivery dates, another thought popped into my mind, how can you show the uncertainty with MONEY!!

    In this case, applies to cost management or even a normal budget, you think?

    Would Box Chart and Gannt Chart help to understand the best case, middle case and worst case when money is spend or planned with these three risks are involved?

    I imagine that this chart could help people who write their budgets get a better understanding of risks affecting their spending.

    Peter

  11. Matthew Galman says:

    Chandoo,

    I like it. How would you display an entry once it has been completed (actual)?

    Thank you,

    Matt

  12. Phil says:

    From what you have shown so far I think that this box Gantt chart is awesome! I think that this could be an extremely useful tool.

    I can't wait to learn how to make my own charts in Excel.

    Will the methods that you are going to teach us work in 2003 as well?

  13. [...] Firday, we proposed a new chart for showing project plans. I chose an ugly name for it and called it Gantt Box [...]

  14. TommyZ says:

    You need to read Eli Goldratt's Critical Chain. The uncertainty you are looking for should be accounted for in a project buffer. Not at each task level.

    Further you should spend time understanding Agile Development. This would have you plan only in 1-3week iterations. This allows you to embrace changes to work not yet started, and for your customer to re-direct your course at regular intervals (after each iteration) throughout your project. keyword search: Agile Scrum

    These items will show you that you are solving a tracking problem for something that you can entirely avoid!

Leave a Reply