On Firday, we proposed a new chart for showing project plans. I chose an ugly name for it and called it Gantt Box Chart.
Essentially, a gantt box chart is what you get when a gantt chart and box plot go to a bar, get drunk and decide to make out. It shows the project plan like any other gantt chart, and it shows the distribution of activity end dates, like any other box plot.
You can see an example gantt box chart for a fictional software project above.
Today, we will learn how to create a similar chart in Excel. Get a steaming cup of coffee or whatever keeps you going and follow these simple steps to make a gantt box chart.
[Read this post if you want to know what GBC is and how to read it]
1. Set up your data:
Just like any other chart in excel, a gantt box chart too requires well structured data. In our case, we need 5 things.
- Activity name
- Start Date
- Best Case End Date
- Realistic (or Plan) End Date
- Worst Case End Date
Getting all the 3 variations of End dates can be tricky. But if you are managing projects for long, you might already know how to get these dates. Otherwise, here is one approach, proposed by Joel Spolsky, called as Evidence Based Scheduling that can help you.
We will also need 3 additional helper columns where we need to calculate some numbers so that our gantt box chart can be constructed without resorting to magic wands. These are,
- BC: Number of days between Start Date and Best Case End Date
- R: Number of days between Best Case End Date and Realistic Date
- W: Number of days between Realistic Date and Worst Case End Date
2. Create a Stacked Bar Chart
Add a new stacked bar chart. The series to be stacked are,
- Best case end date
- R
- W
Use the “Activity Name” column for category axis labels.
Now, our chart should look like:
3. Say your favorite curse word and Reverse the categories
Ok, time for a minor annoyance. Excel has magically showed the first activity of project at bottom. So, we need to reverse the category axis values before any further.
Just select the category axis, go to format axis (press CTRL+1) and click the little box that says “order reverse in Categories”.
Now, the chart should look like this:
4. Add Error Bars to Best Case Series
Now, add error bars to the best case series of the chart so that it looks like a line is drawn connecting best case date to start date of each activity. To do that, follow these steps:
- Select “best case end date” series.
- Add Error Bars (from format ribbon)
- Specify the type of error bar as “Negative only”
- Select “Custom” for error bar values
- Now, point the error bar values to the helper column “BC”
- Format the error bar in such a way that no cap is shown and it is thick.
At this point, our gantt box chart should look like this:
5. Finally, format the chart
Now, our gantt box chart is almost ready. But it is still ugly. We need not hire a Hollywood grade make-up man to beautify this. We just need a few clicks.
- Remove legend
- Add vertical and horizontal grid lines. Make them subtle.
- Change text colors to soothing ones.
- Remove fills from all series in stacked bar chart.
- Apply borders to 2nd and 3rd series to create a box effect.
- Format the date axis,
- Adjust the starting point (unfortunately you have to enter the number equivalent of date, like 1-May-2010 as 40299)
- Adjust major unit – I used 14 days, you can try something else depending on overall project length.
- Set the axis number formatting to d-mmm or mmm or myy or something else that works for you.
- Add a chart title
That is all. Our Gantt Box Chart is finally ready. Now, go figure why your project is not on track and do something about it.
Displaying Completed Activities:
The easiest way to show completed activities is to change all 3 end dates to the same date: that of the actual end date. This way, you just see a line when an activity is done and a box when there are variations in end dates.
Of course, you can use another helper column to show a vertical line or a symbol of your choice to denote the end point as well. I leave it to you to figure out that portion.
Download the Gantt Box Chart Template:
I have prepared an excel template for creating Gantt Box Charts quickly. Go ahead and download the version that you want.
Excel 2007+ version | Excel 2003 version
Here is a mirror with both files as a zip. Go on, be awesome 🙂
Share your experiences of using Gantt Box Chart:
If you like this chart and implementing it in one of your projects, do tell me how it went. Or just share your thoughts on this implementation and any suggestions. Go ahead and share.
Templates & Tutorials on Project Management:
- Excel Gantt Chart Template
- Project Milestones – Timeline Template
- Project Status Dashboard Template
- More resources on using Excel for Project Management
Project Management Template Set – Get a copy today
I have made a set of 24 templates that take care of various activities in a project right from planning to time sheets to issues to project status reporting thru dashboards. These templates have been bought by more than 500 project managers all over the world and they are saving hours of time every week using these templates.
Go ahead and a get a copy of my project management templates.
15 Responses to “A Gantt Chart Alternative – Gantt Box Chart”
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?
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
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 ?
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....
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.
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?
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.
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
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
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
Chandoo,
I like it. How would you display an entry once it has been completed (actual)?
Thank you,
Matt
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?
[...] Firday, we proposed a new chart for showing project plans. I chose an ugly name for it and called it Gantt Box [...]
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!
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