So you have a SPILL error in your Excel tables? In this quick article, let me show you 3 easy fixes to the problem.
Fix 0: See if Excel can auto-fix the formula
This is not really a fix. But if you write certain types of formulas in table, Excel will warn you about the potential spill error and fix it for you. See this example:
One lesson we can take away from this auto-correction of the formula is that if you are using a table column style formula, change it to [@ column] style.
For example:
- Instead of LEFT([Name]) use LEFT([@Name], 1)
- =IF(LEN([Value])>6, “Too long”, “Short enough”) can be =IF(LEN([@Value])>6, “Too long”, “Short enough”)
Note: This auto-correction of formulas is seems to be a new feature, so may not be active in all Excel 365 versions.
Fix 1: Change to a non-spillable formula
If an Excel formula can result in more than one value, it automatically spills. Such formulas are called Dynamic Array Excel Functions. A simple example is the SEQUENCE function.
=SEQUENCE(10)
will return the numbers 1 to 10.
If you use them in a normal cell in Excel, they work ok.
But when you type the same formula in a table, it gives the SPILL error (see this demo).
So an easy fix is to change your formula to a version that doesn’t spill.
Refer to below table to see non-spillable alternatives for some common situations.
| Purpose | Spill Version | Non-Spill Alternative |
|---|---|---|
| To generate row numbers in the table automatically | =SEQUENCE(10) | =ROW()-ROW([#Headers]) |
| Show all matching values with FILTER | =FILTER(data, data=10) | Return only the first matching value: =XLOOKUP(10, data, data) Concatenate all matches into one list: =TEXTXJOIN(“, “,, FILTER(data, data=10)) |
Fix 2: Convert Table to a Range
If you must have a spillable formula in the table column, an easy fix is to convert the table to a range. You will however, loose all the table features (such as structural references, data model connectivity and ability to send data to Power Query).
To convert table to a range, just select the table, go to Table Design ribbon and click on “Convert to Range” button.
Once your table is in a range format,
- Remove any spill formulas in the row 2 onwards in your range
- This will fix the #SPILL! error, as demoed below.
Fix 3: Move the formula outside the table
Tables do not support any sort of spill behavior. So another easy fix is to move the spill formula outside the table to an adjacent column. Something like this:
But what if I need the formula along with my table?
Unfortunately Excel currently doesn’t support having SPILLABLE formulas inside tables. But if you still need a formula result along with your table data (for some calculation purposes), you can use the HSTACK function, like below:
=HSTACT(your_table, spill_formula_here)
For example, I want to add a ID number column to my table. Here is the HSTACK for that:
=HSTACK(my_table, SEQUENCE(ROWS(my_table)))
Why do we even get this error?
It’s not because Excel hates you. There are two things at play here.
- Dynamic Array Formulas: want to spill the formula results down (or sideways) when there is more than value returned by the formula (example: SEQUENCE(10)). They throw a SIPLL error whenever something is preventing the formula from spilling.
- Excel Tables: want to apply the same formula for all cells in the table column.
So when you type an array formula in a table cell, Excel tries to apply the same formula for all cells of the table. This creates a situation where each table row has a formula that wants to return multiple values. So while first row’s formula is trying to spill, second row has a formula of its own (as Excel tables automatically apply the same formula across). Thus the SPILL errors.
Know more about Excel Tables & Dynamic Arrays
Please read below articles to understand Excel Tables & Dynamic Array features of Excel.
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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