ABC analysis is a popular technique to understand and categorize inventories. Imagine you are handling inventory at a plant that manufactures high-end super expensive cars. Each car requires several parts (4,693 to be exact) to assemble. Some of these parts are very costly (say few thousand dollars per part), while others are cheap (50 cents per part). So how do you make sure that your inventory tracking efforts are optimized so that you waste less time on 50 cent parts & spend more time on costly ones?
This is where ABC analysis helps.
We group the parts in to 3 classes.
- Class A: High cost items. Very tight control & tracking.
- Class B: Medium cost items. Tight control & moderate tracking.
- Class C: Low cost items. No or little control & tracking.
Given a list of items (part numbers, unit costs & number of units needed for assembly), how do we automatically figure which class each item belongs to?
And how do we generate below ABC analysis chart from it?
That is what we are going to learn. So grab your inventory and follow along.
(related: ABC Analysis page on Wikipedia)
ABC Analysis using Excel – Step by step tutorial
1. Arrange the inventory data in Excel
Pull all the inventory (or parts) data in to Excel. Your data should have at least these columns.
- Part Name
- Unit cost
- # of units (if this is blank, just type 1 in all rows)
Once the data is in Excel, turn it in to a table by pressing CTRL+T. Lets call our data as inventory. You can set the table name from Design tab.
(Related: Introduction to Excel Tables)
2. Calculate extra columns needed for ABC classification
Now comes the fun part. Crunching the inventory data with formulas. Yummy!
Total Cost: This is just a multiplication of unit cost & # of units columns
Rank: We need to figure out what rank each total cost is (in the total cost column). We can use RANK formula for this.
=RANK([@[Total Cost]],[Total Cost],0) will tell us the rank for each total cost.
Cumulative Units: Once we know the rank of each item, next we need to figure out how many total units are needed for items ranked less or equal.
For example, The number (#) of the third part (PT3959-waes) is 3. Cumulative units for this is 91. This means, 91 is the total number of units for first three ranked parts (parts # 8, 9, and 16).
The formula for this is, =SUMIFS(['# Units],[Rank],"<="&[@['#]])
Remember, [@[‘#]] refers to running numbers (1,2,3….4692,4693)
Cumulative Units %: This is a percentage of cumulative units in total. The formula is simply,
=[@[c Units]]/MAX([c Units])
[Related: using structural references in Excel – video]
Cumulative Cost & Cumulative Cost %:
These are similar calculations (instead of units, we calculate cost)
Explanation of these calculations:
See below animation to understand how the numbers are crunched.
3. Create Inventory Distribution Chart
Select cumulative units & cumulative cost % columns and create an XY chart. Make sure cumulative units is on horizontal (X) axis and cumulative cost % is on vertical (Y) axis.
Our curve should look something like this.
4. Set up ABC classification thresholds
Now we need to decide what is the threshold for classes A,B & C.
For most situations, Class A tends to be top 10% of the items.
Class B would be next 20%
Class C would be the last 70%.
But these numbers may change depending on your industry, manufacturing settings.
Lets say, some where in our spreadsheet, user has defined the thresholds for the classes in a range like this:
So $O$7:$O$9 contains the thresholds.
Next to this range, calculate additional numbers (for plotting A, B & C markers and boxes) like this:
Examine the download file for exact formulas.
5. Add the ABC items & % total cost columns to chart
Add the extra data to the chart (by right clicking on chart and going to select data box & clicking “Add” button).
Once the new series is added, make sure you format it as markers only so that we get something like this.
6. Add Error bars to the ABC markers to get boxes
This step involves adding error bars to ABC marker series and customizing them.
In Excel 2013: Add error bars by clicking on the + button next to chart
In earlier versions: Do this from layout ribbon
Once error bars are added, customize them (select and press CTRL+1). Set error amount to Custom and select the calculated error values as shown below.
Once added, format the error bars to show no cap and change line color to something pleasant.
Now we have boxes on the chart.
7. Clean up the chart, add labels & titles
This is where get creative. After some clean up, we can arrive at something like this.
Download ABC Inventory Analysis Template Workbook
Click here to download ABC Inventory Analysis workbook. It contains sample data & chart. Examine the formulas & chart settings to learn more. Or if you are in a hurry, replace the sample data with your inventory details and get instant results.
Do you use ABC analysis for inventory tracking & control?
I will be honest. I have never worked as inventory controller in a super-car manufacturing plant. That said, I run a business and we do have inventory. Not physical but digital inventory. So I often use analysis like ABC or pareto to quickly figure out where I should focus my efforts.
What about you? Do you use techniques like ABC analysis to narrow down to a few items that matter most? How do you do it in Excel? Please share your tips & experiences using comments.
Add few more techniques to your inventory
Feeling low on your Excel skills inventory? Stock up with below goodies.
- Pareto Analysis in Excel – How to & tutorial
- Analyzing competition using charts – case study
- Track employee vacations & productivity [dashboard & tutorial]
- Track annual goals & achievements
24 Responses to “10 Supercool UI Improvements in Excel 2010”
The best improvement by far is the Collapse Ribbon ^ button !
Kind of a shame that some of the best improvements are actually returns to old functionality. One thing I don't like is that to get to recent files I need to do an extra click after File - apart from Save As, that's why I'm usually in the File menu. I like the sparkline options, though they are still as not fully featured as some of the free and pay options out there.
The collapse button for the ribbon menu is good news. Can you make the ribbon menus stick too?
Nine improvements, not ten. You can also select multiple objects in 2007. Click on the Find & Select item at the far right of the Home tab, and the dropdown looks remarkably like your 2010 screenshot.
@Jon.. Thank you. Dumb me, I somehow thought we couldnt select objects in Excel 2007. Just saw the "select menu" and it is there. I have corrected the post and removed the point. I have added the "you can make your own ribbons" instead. Thanks once again.
@Arti: what do you mean by make ribbons stick?
@Alex: May be it is my installation, but when I go to "File menu" I see "recent files" by default.
For example, if I am working with one of the contextual ribbon menus (Pivot tables, Drawing/Chart etc), as soon as I click away from the selected object, the menu tabs vanish. If I click on the object again immediately, then Excel will remember what I was looking at, but if I wander away and click on a Pivot, then back again on the Chart, the menus will 'appear' but not get activated, thereby causing much annoyance and additional clicking.
I want to "pin" the whole menu (not invididual commands) somehow, so that I can have the menu there for the length of the time I am working with graphics. Excel 2003 used to have the Drawing toolbar you could detach and hover while you were working, but this functionality disappeared in Excel 2007.
My thought was Excel should just allow a 'pin', similar to the Recently Opened files menu, for the Ribbon Menus as well. If I have not selected any Drawing object, the commands can be greyed out, but I want the menu as a whole to 'stick'.
@Arti... I think MS solved this problem differently. When I select a pivot and go to "design" tab Excel 2010 remembers this and automatically takes me to "design" tab when I reselect the pivot.
Apart from this you can also define your own ribbon with all the things you normally do. See the above article (I have added this after Jon's comments)
Nice feature. About time for a upgrade for MS Office
Oh... okay. That might be a start. I'd probably just copy-paste the Drawing tab haha. Thanks. I'll definitely give Excel 2010 a try.
Btw - have you considered getting into / gotten into the world of Excel as it meets SharePoint?
Actually, the replacement new thing is probably better than all the rest. One thing that the designers of the Office 2007 ignored was allowing regular users to customize their own interface. Office 2010's interface was expanded in this way to address the huge uproar.
Is there still a limit on how many things you can add to the QAT bar? (I'm too lazy to look myself.)
@Jeff.. it seems to take quite a few, but only shows one line and gives a little arrow button at the end. (summary: shucks!)
The best thing is you can edit the ribbon directly from excel, so now i can create my own bar with just the things I use regularly!
One of the annoying things in 07 for me is the Add-Ins menu bar - in 03 I could keystroke directly to menu add ins.. In 07 I needed an extra keystroke just to activate the add-in menu, then the keystrokes as normal.. Hope this marek sense..
John -
If you remember the old Excel 2003 Alt-key shortcuts, you can still use them in 2007. To get to the Add-In dialog:
Alt-T-I
Dear Arti & Chandoo
Seen your comments over some issues. Hope you are form India, gone through your comment expecting a pin to command it as a whole, great, hope if someone out of MS have read it, it may be kept in mind while the next R & D of Office Ver. 16
Just incase someone forgot CTRL+F1 will collapse the ribbon.
[...] was pleasantly surprised when I ran Microsoft Excel 2010 for first time. It felt smooth, fast, responsive and looked great on my [...]
I like the sparklines, and the ability to modify the charts
How do you get rid of the advertisment on the right hand side? If you upgrade then will it take off the ads?
Once again Microsoft has re-decorated the Office and we are NOT pleased!
The graphics object selector can be found in the Home ribbon under Find & Select, Select Objects near the bottom of the drop down. You can make it part of the Quick Access toolbar by right click over it and selecting Add to Quick Access toolbar.
The graphics "cursor" will now appear on the mini-toolbar at the top left of the window.
How to get rid of "Add-Ins" button in Backstage (File)" menu by means of XML code, i.e. to hide, to delete or to disable this button?
This button is usually situated in the Backstage menu between "Help" and "Options" buttons.
Vladimir, did you ever get an answer to your question?
I am tying to customize the ribbon UI for a file using XML, and this is precisely the piece I can't figure out. I can hide other tabs, remove items from QAT and backstage - all except the options that are showing up under add-ins in backstage. If there is an XML syntax for referencing this thing and making it invisible, I cannot find it.
Hey, nice tutorial. Please check my video tutorial on similar topic at the below link and provide your comments:
http://www.youtube.com/watch?v=TeIFc0jYjpA