Often when we make a survey to compare various products (or vendors, companies, brands) the results are in the following format:
Now, we can visualize such data in several ways. One of the obvious ways to visualize is to make a stacked bar chart. But it results in poor representation of values as we cannot easily compare ratings of one vendor to another. This is where a panel chart would help. A sample panel chart for above data can be like this:
A panel chart (often called as trellis display or small-multiples) shows data for multiple variables in an easy to digest format. It lets users compare in any way and draw conclusions with ease.
Today, I want to discuss how the principles of panel chart can be applied to visualize a complex set of survey results. For this we will use the recent survey conducted by Gartner on how various customers use BI (Business Intelligence) tools. The folks at Tableau have done good analysis of this data and presented the results in this format:
While the above chart is ok, it doesn’t let you compare vendors very well. We can only compare them on first usage, “viewing static management reports”. For everything else, the base line changes, so it is difficult to draw meaningful conclusions if, for example, you want to know which software is getting used more for “doing complex adhoc analysis”.
Jon Peltier has done beautiful analysis of this chart and presented various alternatives in his post yesterday. One of his recommendations is, of course, making a panel chart like this:
While, Jon’s Panel Chart greatly improves the readability of these survey results, I have 2 problems with it.
- Making such a panel chart in Excel is like baking your own bread. If you are like me, after few hours, you would run to bakery both hungry and frustrated. Panel Charts are not native in Excel. That means, we have to bribe, coax, threaten, protest and bend over backwards to prepare something like this in Excel. Thankfully people have already done that. So we can follow the examples and learn from their lead. [here is a panel chart tutorial from Jon]. However, the point still remains that, creating a panel chart in excel is a pain.
- Once such a panel chart is constructed, it is still pretty rigid. For eg. if you are interested in knowing how IBM as a BI vendor fares, you would like to have the results sorted by IBM’s BI Usages, but doing that in this carefully weaved panel set up means going to square 1 with less dough. So, we are stuck with a panel chart where the values cannot be sorted by any one vendor.
Is there a simpler way to construct panel charts in Excel?
So, I wondered, “is there a better and simpler way to make this chart that would still let me compare values (by BI vendor or BI Usage), let me sort and still save me enough time to drive down to one of the best bakeries in town to get a nice fluffy donut?“.
Of course there is…
The trick is to use Incell Charts. Ahem!
Instead of carefully tweaking chart options, adding dummy series and hiding them in the charts, we can just use incell charts with REPT formula and then align them in the cells. Since Excel naturally has the grid layout, creating panels (or small multiples) is as easy as snapping your fingers. (pls. note, this method of panel chart is only applicable for bar / column charts. If you need panels of line charts or scatter charts, you still need to use the methods suggested by Jon.)
We can also easily add a sorting option and use the lovely LARGE formula to sort the results based on selected vendor.
Here is what I prepared using the above recipe and it took me less than 20 minutes to set this up.
[click here for larger version of this]
How is the above incell panel chart constructed?
I am sure you are eager to know how this chart is constructed. Here is the secret:
- I took the raw data from Jon’s site and then Pivoted it so that we get the survey results in a table (with vendors on top and usages on left).
- I have dedicated a cell to let user select the sort order. Let us call this cell as “K3”
- Based on the vendor selected in K3, I have sorted the entire raw data using LARGE formula (and generous use of MATCH, INDEX, OFFSET formulas as well – examples here and here).
- Then I used the REPT formula to plot the incell bar charts (and the font “play bill” so that the bars look thick and nice).
- I have topped this with conditional formatting so that sorted vendor can be highlighted in different color.
Download the Incell Panel Chart Workbook
Download the Incell Panel chart workbook to play with it. I am sure you will find something useful and fun in that. [mirror download link]
How would you chart survey results?
There are still few problems with this approach though (for eg. adding labels can be a pain), but all in all, this simplifies the charting task and leaves room for adding extra features like sorting, conditional formatting.
Here is a open invitation. We have a long weekend coming up, thanks to Easter. So go ahead and download the original data here. And make your own charts for this survey data. The objective is that we should be able to compare vendors with each other with ease. Save your charts as images and upload them somewhere. Then leave a comment here with that URL so that we all can know how you would chart survey results.
Also, share your opinion on this type of panel charts. What is your experience with them? Do you like / hate panel charts?
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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