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
28 Responses to “Team To Do Lists – Project Tracking Tools using Excel [Part 2 of 6]”
[...] & tracking a project plan using Gantt Charts Team To Do Lists - Project Tracking Tools Part 3: Preparing a project time line [upcoming] Part 4: Time sheets and Resource management [...]
the templates are great (I bought the combo).
What I'm missing is a way to have the project gantt chart and reporting with the data per resource, in such a way that I can also show the occupation per resource on an extended gantt chart.
So with hours entered per person per project or sub-activity, to show a gantt chart of how many hours/days a person spent on which project (or plans to spend).
[...] from: Team To Do Lists - Project Tracking Tools using Excel [Part 2 of 6] 25 Jun 09 | [...]
Hi Chandoo,
Funny I have a post on the value of MS project lined up which I will post when the current monster project I'm working on finishes and I get some free time!
I'm not sure this would help with any of the projects I've worked on, closing down a to do list seems like more effort than it's worth, but it might be useful for some things. I guessing it doesn't, but does the time stamp not update when you recalculate the work book?
keep up the good work!
Ross
@Ross.. Thanks for sharing your ideas... I think to do lists are a great way to keep up with project activities and ensure accountability from individual team members, when they are implemented right.
"I guessing it doesn’t, but does the time stamp not update when you recalculate the work book?"
Your guess is right. When you change the calculation mode to "iterative", excel takes care of the nittygritties and retains older values in circular references in formulas.
[...] Project Management in Excel [New Series] - Gantt Charts | To Do Lists [...]
[...] & tracking a project plan using Gantt Charts Team To Do Lists - Project Tracking Tools Project Status Reporting - Create a Timeline to display milestones Part 4: Time sheets and Resource [...]
Hi Chandoo,
The template give me lot of convenience to monitor the thing to do. It simple. Thank You
[...] & tracking a project plan using Gantt Charts Team To Do Lists - Project Tracking Tools Project Status Reporting - Create a Timeline to display milestones Part 4: Time sheets and Resource [...]
[...] make sure you have read the first 4 parts of the series - Making gantt charts [project planning], team todo lists [project tracking], project time lines chart [reporting] and Timesheets and Resource Management using Excel. Also [...]
Chandoo,
I really do not see any befit to this function in Excel unless it was somehow tied into some other chart. That is say a scheduled activities % complete is based on the to-do list.
The only way this chart would be useful is if no one was assigned none dependent task that could be done by anyone. The cases were both of these conditions are true are so few and far between it really makes this chart worthless.
@Brian... Once you have a todo list up and running, it is easy to get metrics out of it. I didnt propose it as it might look a bit too micro-management-ish.
I am able to understand what you meant by "The only way this chart would be useful is if no one was assigned none dependent task that could be done by anyone. The cases were both of these conditions are true are so few and far between it really makes this chart worthless."
Can you explain?
"Chandoo"
What I mean is this. Lets say you have 10 task which are part of one activity/WBS that is in your schedule. One there are very few cases were many people would be assigned to complete this one scheduled activity with no direction being given who should what of the 10 task. It is poor management, and the task 90% of the time would not get done in a timely manner if say 4 people were responsible. Secondly, you are assuming all 10 task are independent of each other. You might need to do task 1 thru 3 before you can do task 4, and to do task 7 you might need to do 4 and 6. Thirdly, the time it would take to compile and then fill out the to-do-list even in limited applications is really not worth it.
I just see almost no applications why a team would need to inform others separate from the schedule that they have completed a task on a to-do list unless anyone of the 4 people could of completed that task.
My point is, there might be a few very limited applications for this type of list but this list would be worthless as a Project Management tool in every other case.
However, change this from a to-do-list to a document change log and it is perfect. Instead of to-do it is the documents name or summary of what changed in the document. The person is who edited the document, and the time stamp is when they checked it in. But I do not know why you would use excel when there is free software you can use commercially that is 10 times better that does document management.
I think using excel to do Project Management over a real Project Management application is a bad idea. Unless you are running a very small, simple project, the time and effort is a lot more to use excel compared to the cost of the Project Management software.
This comes back to my point, I love your site, however, just because you can do something in excel does not mean you should do it. To often the time it takes to use excel is wasted 10 times over from the cost of doing it in an application designed to for the specific application.
@Brian: The todo list mentioned here is meant to keep track of all the tasks for which detailed planning is not necessary but some sort of tracking is needed. These are not be confused with project activities (a la gantt chart).
I like your suggestion about using this as a document tracker. Pretty cool use.
Coming to your point about excel as a real project management tool, well, I have my views, but in a serious project environment, it would surely payoff to have a dedicated project management application.
[...] & tracking a project plan using Gantt Charts Team To Do Lists – Project Tracking Tools Project Status Reporting – Create a Timeline to display milestones Time sheets and Resource [...]
Chandoo,
Wonder how the timestamp column will maintain its previous data. Both Today() and Now() functions will update as and when the next timestamp happens.
[...] Preparing & tracking a project plan using Gantt Charts Part2: Team To Do Lists – Project Tracking Tools Part3: Project Status Reporting – Create a Timeline to display milestones Part4: Time sheets and [...]
I've combined this with the issue tracker since I like the automatic date stamp, but one thing I'm noticing is that I can't replicate the chart that goes along with the issue tracker because the cells that are referenced have the formula that inserts the time stamp instead of a the actual date value. All the dates of the last 30 days display 0 when they should have a value.
Is there a way around this?
I have edited the chart so that my team members can update the percentage completion of the assigned tasks. When the cell is updated, i would like the time stamp to update. How would I manipulate the formula to update whenever the drop-down list is changed?
[...] … ??? To Do List [...]
Excel is great however sometimes you need to get a better idea of what tasks each person on your team is working on at any given time. We've developed a web app that can do just that! Each person has a list of tasks, listed in the order they have to complete them.
HII,
I want to expand the database through excel where i am working on 11 cities as of now and i want to expand it upto 50 cities and hence forth the data related to it will also expand so i want to make it precise where i can get updates also that this work is required to be done at that particular day or date
Thanks for making all of this information available for free. I am currently using excel to track everything for the first time. I later plan to output our information here with a more visual presentation. Wish me luck!
Can some one point me out to some additional direction on the "Who Finished it?" column? Something more 'basic' for a newbie excel guy? lol I got everything else working on this tutorial but that column. I can't seem to recreate it and I know a lot of it is due to lack of knowledge with VB code. I'd like to recreate this column very much 🙁
Dear Chandoo,
Thanks for the team to do list, kindly let me know how to set the column who " finished it " from another work sheet
Hi Chandoo,
Unable to download it - can you please check the link and confirm.
Great inhisgt! That's the answer we've been looking for.
Hi Team,
I know u all are the best programmers in the world!!! that's I am here to rectify my issues. here is my question please ans me as soon as possible before 8-3-2017 its really urgent.
I have a project named the production tracker.
1) I require the user form which shows the names of the Associates which are linked to the different tracks. when the user is selected the particular track related details and dropdowns should appear.
2) I need to track the associate needs how much of the time to complete the particular task. with start stop and pause and resume timer.
3) It should display the daily count of the production and save the data to the another Excel file.
this production tracker should save all the data no matter how many people logs in into it.
Please help me for this it will be very appreciated.
you can directly email me on my mail ID: tusharkch694@gmail.com