Last Friday, we had a fun little Excel challenge – Calculate Maximum Change. More than 170 people commented and shared their solutions to this problem.
And the best part?
The best part is the variety of solutions & thinking displayed by our community. So if you are one of those 170, puff your chest & pat yourself on the back. Go ahead, I will wait.
Today, lets take a look at some of these awesome formulas and understand how they work. Read on and watch the video you below to gain few awesomeness pounds.
First, lets understand the problem
Here is a look at the problem:
We need more information to answer this question.
- Are we talking about positive change, negative change or absolute change?
- Are we talking about % change or value change?
In the original problem, even though I did not mention it, most people assumed that we want absolute change of value (ie the answer is 40, for Product 2).
But in real life, you may want to understand the problem a little more before writing any formulas.
Note: The data is in C3:C8 for last month and D3:D8 for this month.
Solution #1: Using MAX array formula
This is the solution most people got.
The array formula:
=MAX(C3:C8-D3:D8)
press CTRL+Shift+Enter after typing.
How it works?
C3:C8-D3:D8 portion: This gives the result {-20;40;15;21;0;-25} in array form.MAX(…) portion: This simply calculates the maximum value of above array and returns 40 as answer.
Why press CTRL+Shift+Enter (CSE)?
We need to press CTRL+Shift+Enter because MAX() is not capable of handling arrays. If you write MAX({-20;40;15;21;0;-25}) you would get 40, but the same array when calculated by doing math on ranges will not work. To force MAX to treat arrays, we need to press CTRL+Shift+Enter.
Solution #2: Using MAX+ABS array formula
Quite a few people figured out that the formula needs to work even when the change is negative. And that is where this new solution comes handy.
The array formula:
=MAX(ABS(C3:C8-D3:D8))
press CTRL+Shift+Enter after typing.
How it works?
ABS() portion: converts the change values {-20;40;15;21;0;-25} to positive {20;40;15;21;0;25}
Rest of the formula is same as solution #1.
Solution #3: Using INDEX to avoid Ctrl+Shift+Enter
The thing with Ctrl+Shift+Enter is that you have to remember it. If you accidentally press Enter instead of CSE, the formula stops working. One way to avoid this is to route the calculation thru an Excel function that can natively process arrays. This is where INDEX (or SUMPRODUCT etc.) come handy.
The formula:
=MAX(INDEX(C3:C8-D3:D8,0))
or
=MAX(INDEX(ABS(C3:C8-D3:D8),0))
How it works?
Same as Solution #1, except for this formula you do not have to press Ctrl+Shift+Enter. The INDEX will automatically calculate the array and send numbers to MAX. Then MAX feels mighty comfortable dealing with those numbers and spits out the answer as 40.
Learn more:
Solution #4: Using AGGREGATE
AGGREGATE() is a new function introduced in Excel 2010. This too, like INDEX & SUMPRODUCT can process arrays natively (provided you are using one of the aggregates like LARGE). Kyle, one of our commenters shared 2 brilliant solutions that involve AGGREGATE.
The formula:
=AGGREGATE(14,4,(C3:C8)-(D3:D8),1)
How it works?
14, 4 portion: This tells AGGREGATE that you want to calculate LARGE value (14) and you want to consider all cells (4). To understand more about AGGREGATE see the links below.
(C3:C8)-(D3:D8) portion: As seen above, this just gives an array – {-20;40;15;21;0;-25}
1 portion: This tells AGGREGATE that you want 1st largest number.
Learn more:
Solution #5: Using MMULT and AGGREGATE
Now this is what I call a scary formula. It can potentially waste your entire afternoon when you try to understand it first time. But once you get it, you feel awesome. This too is posted by Kyle.
The formula:
=AGGREGATE(14,4,MMULT(C3:D8,{1;-1}),1)
How it works?
Watch the video. Explaining how this works in text is difficult.
Learn more:
I am still trying to understand MMULT(). It can be as complex and deep as string theory (or recipe of making bread at home). Go thru below links to learn more about it. Make sure you put on your helmet, cause it will blow your mind.
More ways to get maximum change + Bonus problem
Watch below video to understand how to solve the maximum change problem and another related problem.
Click here to watch if you can’t see the video above
Download Answer workbook
Click here to download answer workbook and examine the formulas to learn more.
What did you learn from this formula challenge?
I learned how to use AGGREGATE, Array SUMIFS and got a better handle on MMULT.
What about you? What did you learn thru this challenge. Please comment and let us all know.
25 Responses to “Display Alerts in Dashboards to Grab User Attention [Quick Tip]”
I prefer the red,grey,light grey,black icon set. I've also used in-cell pie charts from Fabrice's Sparklines for Excel as an alert which could also provide another piece of information.
I prefer the red,grey,light grey,black icon set. I've also used in-cell pie charts from Fabrice's Sparklines for Excel as an alert which can also provide another piece of information.
For Excel 2007, your formula should do the same as the Excel 2003 version, so that non-alert rows are blank - if they are 0, the unnecessary green icon will show
Hi Chandoo,
Nice Post !! just to add something for EXL 2003, we can also 4 Ifs and link to the alert data
For Ex: If we have alert data in Cell A2 and want to split in 4 orders namely <25%, 25-50%, 50-75% and 75%< then we can following formula and put fonts as you have suggested :
=IF(A2<0.25,CHAR(153),IF(A2<=0.5,CHAR(155),IF(A2=0.76,CHAR(152)))))
And then using Conditional Formating we can dashboard reflected on different COLOURS as per their respective alert.
Best Regards
Rohit1409
Hi Chandoo,
Nice Post !!! just to add something for EXL 2003, we can also 4 Ifs and link to the alert data
For Ex: If we have alert data in Cell A2 and want to split in 4 orders namely <25%, 25-50%, 50-75% and 75%< then we can following formula and put fonts as you have suggested :
=IF(A2<0.25,CHAR(153),IF(A2<=0.5,CHAR(155),IF(A2=0.76,CHAR(152)))))
And then using Conditional Formating we can dashboard reflected on different COLOURS as per their respective alert.
Best Regards
Rohit1409
The Complete formula [Don't Know how it got cut ]
=IF(A2<0.25,CHAR(153),IF(A2<=0.5,CHAR(155),IF(A2=0.76,CHAR(152)))))
PS : Use in single line [I have split it to avoid cuts 😉 ]
Hi Chandoo..
why it is not displaying the complete formula..
anyways here is the balance
"=IF(A2<0.25,CHAR(153), IF(A2<=0.5,CHAR(155), IF(A2=0.76,CHAR(152)))))"
@Rohit... your formulas are fine. Just that the width of comment area is fixed and hence my website is cropping it at 640pixels. I just edited your formula and added few white spaces so that it wraps nicely.
Very good idea btw.. kudos!
Hi,
Maybe just go for 'bold' ; 'underline' or 'italic' to draw the users attention? Those methods (if those can be called methods) are used cross media type (books, journals, blogs, billboards, ...) to guide the readers eye to valuable information.
Just a basic thought
@Tom.. good idea..
[...] has a very nice writeup on how to add such alerts to dashboard sheets. Possibly related posts: (automatically generated)Divide your data set into workbooksHow to enforce [...]
Hi Chandoo,
You certainly grabbed my attention! although I wasn't sure what my brother (Suresh) and cousin (Shyam) were doing right, and I was doing wrong? 😉
I love your blog btw - Many thanks for all your hard work in unravelling the secrets and mysteries of Excel!
Best regards
Ramesh
I thought I saw an advertisment for a book about learning excel called excel himalaya or something. It cost about 35.00 us money but seemed to have the things I need to have my admin assistant to start to use. I was hoping to start with this book and then send her to school if she shows some interest and aptitude. Any help on this would be appreciated. Thanks
Great web site and information!!!!
@Jeff... checkout http://chandoo.org/wp/2010/08/25/excel-everest-review/
thanks, your website is awesome!
[...] Alerts to highlight focus areas [...]
[...] There are lots of numbers in this dashboard. I would suggest adding few more visualizations like showing indicators or applying conditional formatting or replacing a table with a chart. This would reduce the [...]
[...] is the same technique as alert icons in dashboard. Just that I also showed green [...]
[...] is the same technique as alert icons in dashboard. Just that I also showed green [...]
Hi Chandoo
Firstly thanks for all the cool tips on how to use Excel better.
I am new to the site and have a question which you may be able to assist with but dont know if these comment boxes are the best way of asking ?
I am looking at assets and trying to calculate the depreciation total by taking a year (say 2010) adding the expected life of the asset (say 10 years) then comparing that to a future date (say 2015) using an IF statement. The calculation in normal is - IF((year in col B (2010) plus 10years)>year 2015, add a years depreciation, otherwise leave blank). The converted date value does not appear able to add 10 years in order to compare it to 2015. Am I missing something ?
I use the “IF” Statement in conjunction with Conditional Formatting in MS Excel to give verbiage to alert one of a required action, dependant on a review date. This makes a visual stimulus, plus it clues one as to what the conditional format is trying to warn you about and what follow-up actions are required.
Wow, I'm really impressed with dashboards. I had no idea this stuff was even possible with excel. I'd like to offer an interactive dashboard to my customers, showing analytics of their data. I have a .pdf file with the datapoints. I'd like them to enter the data on my website, and be able to see their data. Is something like that possible.
Hi Chandoo,
I've recently purchased the package for both templates.
In the portfolio dashboard,under the calculations worksheet, I'm attempting to change the date range in the gantt chart to show only the range of the project that starts in late 2013. How do I do this?
Thanks
Adam
[...] is the same technique as alert icons in dashboard. Just that I also showed green [...]
Hi Chandoo,
I'm new at Excel Dashboard and found your blog really useful and helpful! It's very nice of you that you dedicate your time to do this.
Could you please explain how can I use Alerts based on dates on a Dashboar?
For example, if a target date is coming closer to the actual date, the alert is yellow or red.
I'd really appreciate some help!
Thank you
Where can I download the file Excel of Averall Statistics ???
Thanks a lot.