In April 2011, Mdsuhair asked a question at the Chandoo.org Forums
This is a candidate for Solver.
This post will walk us through the solution to the problem using Solver. It uses Solver and screen shots from Excel 2007.
All versions of Excel have solver available. Users should note that the screen shots may not match your version although the functionality will, some of the functions appear in different locations in different versions of Solver.
What and Where Is Solver
What is Solver
Solver is an Excel add-in that can solve problems by enabling a Target cell to achieve some goal.
This goal may be to minimse, maximise, or achieve some target value.
It solves the problem by adjusting a number of input cells according to a set of criteria or constraints which are defined by the user.
Where is Solver
Solver is an Excel add-in supplied with Excel, but not enabled by default.
To enable solver
File, Excel Options, Add-ins, Manage Excel Add-ins, Select the Solver Add-in checkbox
Solver will now appear as a New Tab on the Data, Analysis Tab
Solver Example
This post is based around a worked example Solver Example File, the file is compatible with all versions of Excel.
Defining the Problem
Mdsuhair had a series of 8 Items each which had a value:
He wants to know which items should be combined so that the sum of the values of the items is nearly equal.
To do this we need to assign each item into a Bucket. Namely Bucket A and Bucket B.
We will put values of 1 into a Bucket for each Item to show that it is assigned to that Bucket and a value of 0 to show that the bucket is empty (In/Out) Value.
We can start by adding a Total Column, which counts items in Buckets A + Bucket B for each Item, It then totals the totals.
We also know that we need to work out the Value of each Item in each Bucket
We do this by multiplying the Items Value by the Buckets (In/Out) value
Finally we need to add up the values in each Bucket and work out the difference between them
Mdsuhair’s original problem was to minimise the difference between the sum of the values in the 2 buckets.
Now we can place values of 1 in the buckets manually and Excel will show us the value of each Bucket and the Difference between them in Cell G11.
I have applied some conditional formatting to show when a cell has a value > 0.
The problem is that there are 28 or 256 combinations of answers, and to test them all manually at 1 every 5 seconds would take 21.3 minutes, assuming we can keep up that pace and remember which was the best combination.
This is where solver comes to the fore.
Applying Solver
To apply solver we need to define a series of requirements, rules and constraints.
These requirements, rules and constraints guide solver and set limits which allow solver to quickly narrow in on the answer.
What are our rules
Our main requirement is to minimise the difference between the value of the 2 buckets.
The difference between the 2 buckets in our example is cell G11, the sum of Bucket 2 values minus the Sum of Bucket 1 values.
We want to have G11 as low as possible but greater than or equal to 0.
We also know that an item can only be in Bucket A or Bucket B, it can’t be in both and can’t be Broken apart.
That is 2 Constraints for each Item
Firstly The Total column must be equal to 1
Secondly the Buckets Values must be Integers
We also know that the Total Number of Items is 8, this is another constraint.
We will discuss how these constraints are used in the next section
The Solver Window
This section will explain the solver window and its use in defining the problem within solver.
A Blank Solver Window
A Filled Solver Window
Set Target Cell:
This is the Target cell which is the cell which you are trying to solve the problem for.
Our Target cell is G11, The difference between the 2 Buckets values
Equal To:
The Equal To: section defines what we want to do with our Target Cell.
We want to achieve the same value in each Bucket and so the difference between the Buckets will be 0.
It might sound strange but we don’t want to minimise that difference. A minimal value will be achieved when all the Items are placed in Bucket A, as our equation for G11 will then have 0 – Total which is –Total, which is more minimal than 0.
Another way to constrain this is to Change G11 to =Abs(G10-H10)
This allows us to use Min as an Equal To: Value
But for now we can just leave G11 as =G10-H10 and we will set the Equal To: section as 0.
By Changing Cells:
Changing Cells: refers to the cells which will be modified by Solver to try and solve the problem.
We want to let Solver change the number of items in each bucket, this is the range: $C$2:$D$9
Hint: You can try the Guess button next to the Range Reference and Solver will take a Guess at what cells the problem is dependent on.
Always check this if you use it, especially in complex models.
Subject to the Constraints:
Constraints are the rules which define the limits of the possible solutions to the problem
We will add several constraints for our rules:
1. The Total column must be equal to 1 for each Item
2. The Bucket Value must be an Integer
3. The total contents of the 2 buckets must be 8 items
4. You could add a further constraint that each Bucket should hold the same number of items
Hint: As a general Rule, Under Constrain rather than over constrain! You can always add more constraints later.
To do this we will use the Add Constraint Button
1. We need to add a constraint for each cell in the Range E2:E9 that it is only allowed to be = 1
This constraint must be applied for each cell in the range E2:E9
2. We need to add a constraint for each cell in the Range C2:D9 that it is only allowed to be an integer
This constraint must be applied for each cell in the range C2:D9
3. We need to add a constraint for the Total of the 2 Buckets, E10=8
You can Change or Delete Constraints if you make a mistake by selecting the appropriate constraint and using the Change or Delete Buttons
Save and Load Solves Parameters
Selecting the Options Button there is the Option to Save Model and Load Models.
Hint: The Save/Load Models has been shifted onto the main Solver dialog in Excel 2010.
Using the Save Model and Load Model options you can Save and the Load the Solver Parameters for your model. The Save Model saves the parameters in a Range of cells as shown below.
This allows an easy way to actually setup and/or change the solver parameters.
Hint: Setup one constraint using solver then Save the model. Edit the model on the worksheet and re-load the model as required.
Note: That the parameters although when saved show as True/False or Numbers are all Excel Equations, see above.
This means you can edit them to change the Constraints and Parameters as required and re-load them into solver.
I have included 3 sets of Parameters for our model.
These are:
- Base Case – Forces bucket values to be equal, Allows uneven bucket counts
- Equal Sized Buckets – Forces each bucket to contain the same number of items
- Force an error – Which forces an error in the solver model
Load each model and try them at your leisure.
Running the Solver Model
Warning: Solver is a computationally complex add-in, so once your model is setup, Save your Workbook.
Prior to running the model there are a few parameters we should look at to ensure the model solves correctly.
On the main Solver window select the Options button. (Some of these parameters are on the Main Solver window in Solver 2010)
Generally you can accept the defaults but in this case we will change the following
Assume Linear Model – Select
Assume Non-Negative – Select
Note: Solver in Excel 2010 will return a better answer without these 2 parameters enabled by default
The other 2 parameters which you may need to change from time to time is
Precision: Precision is a number from 0 to 1 and higher means more precise
Tolerance: Tolerance shows how far away from a Number, an Integer constraint is allowed to be
The use of the Estimates, Derivatives and Search parameters are beyond the scope of this post. I direct you to the Excel Help on these subjects, by selecting the Help button.
Run the Model
To Run the Model, select the Solve Button from the main Solver menu.
The main status bar in Excel will flash up a number of statistics about the internal workings of the Solver add-in. Generally these flash by and are too fast to read. If a model is too complex it may stall and you won’t see any movement for a while. Solver generally recovers from these problems itself.
Once the Solver model finishes it will display a dialog of the results and allow you to do several things
First thing to note is that “Solver Found a Solution“.
If it has found a solution, the worksheet cells will be changed to show the solution
You now have 4 options:
- Run a Report
- Save a Scenario
- Return to the model
- Check Your Results
Run a Report
Run a report by clicking the report you want.
A new sheet will be added to your workbook depending on the report but will be called:
- Answer Report 1,
- Sensitivity Report 1
- Limits Reports 1
etc.
Note, that not all reports are relevant at all times, depending on the Constraints you have applied.
Save a Scenario
Selecting the Save a Scenario button takes you to the Save Scenario dialog.
Type in a Name and the Scenario of your model is saved as a Scenario.
Scenarios as available for use in the Scenario Manager, which is accessed from the Data, What-If-Analysis Tab
Return to the model
You can return to your model and either:
- Keep Solver Solution
- Restore Original Values
Check the Results
Solver is probably the most Black Box’ish of systems within Excel. As such any results it puts out must be manually checked for suitableness before further use.
These checks for realness, should as a start confirm that the results meet all the criteria supplied.
Are the results roughly what were expected?
Are any Minimums or Maximums violated?
What If Solver Doesn’t Find a Solution?
From time to time Solver will return with an error that a “Solver could not find a feasible solution.”
When this happens it is indicating one of several possibilities:
- Your model is over or under constrained
- Your model constraints are impossible to meet
- Your model constraints have an error
Start by checking the current constraints for errors and ambiguities
Eg: in our case we have 8 items so requiring the Count of the two buckets to be 20 is impossible to meet
My Solver Answer has Strange Numbers?
In solver up to and including Excel 2007, solver would commonly return numbers like 3.5E-18.
This is 0.0000000000000000035, which is effectively 0
If your model returns these, feel free to go through the model and change them to 0, in our model we should also check as the corresponding 1, may in fact be 0.9999999999999999965.
It should be noted that this problem in Solver in Excel 2010 does not occur as often but will still occur.
What and How have you used solver in the past?
What and How have you used solver in the past?
Let us know in the comments below:
49 Responses to “Introduction to Slicers – What are they, how to use them, tips, advanced techniques & interactive reports using Excel Slicers”
Great article!
If you want to learn a bit more about using slicers in VBA, head over here:
http://jkp-ads.com/articles/slicers03.asp
Hi
I downloaded cube-formula-slicer-selection.xlsx.
Why is 'Report Connections' grayed out?
Great article!! Thank you very much... This post is one of the most helpful for my job!
Great Introduction. Thanks very much.
Wow! trying to use this on the reports that I have now. I really liked that Quantity and Amount Bar graph used on the pivot-multi tab, but for the life of me, I can't seem to replicate it from scratch. Help please?
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This is awesome! I will favorite this page in my blog, http://www.exceltoxl.com
Since I've known slicers about 2-3 yrs ago, I've pretty much used them in every damn report I do. Everyone that sees it for the first time is like "This is the best thing ever. Did you do that using excel or something else?" 😀 My bosses are so used it that when they see a report from someone else that doesn't have slicers they send it to me to redo it :).
Couple of tips:-
Tip 1:
If for lack of space or say you want ability to search within a filter due to numerous values being present but still want it to connect to multiple pivot tables or charts then
1. Setup a pivot table with just the report filter
2. Create a slicer with the same field and tie that to all the pivot tables/charts that you want.
3. Just place it some out of sight.
Now you have a dropdown with all your values with search option plsu it is also connected to all your charts and pivot tables.
TIP 2:
In Excel 2013, slicers can be used with just plain tables as well. Not limited to pivot tables.
Congrats!
Nice content : )
Very comprehensive. Explained in an extremely simple way. I have been using Slicers for a while, but still learnt new things from this post. Thanks for sharing. Best wishes.
Awesome Explanation !!
I have joined this blog recently. Brilliant tools are available that I started using in my day to day work. Brilliant site. Thanks heaps.
[…] Read the full article here: Introduction to Slicers – What are they, how to use them, tips, advanced techniques & interact… […]
Oh wow. I've only just started using Excel 2010 and had no idea this even existed. It makes dynamic charts so much easier!
You are my Hero! I am working with PowerPivot due to the huge amount of data I have and could not use my usual tricks to get the scatter chart title to change. For some reason the CUBE function wouldn't work (who knows why, I don't have time to dig into it now) but your "dummy" solution did.
thankyouthankyouthankyou!
Clare
On a normal PivotTable filter, you can choose whether to allow multiple items to be selected or not. Is that possible with slicers (in Excel 2010)? I've had a look through the options and not found a way to do it yet!
Hi Stevie... this is not possible with slicers.
Just hold down control when you're choosing them...can then either click another (without control) and it will show only the new one, or click the filter with the red 'x' to revert back to all options.
Not a limitation that can be placed on the slicer but still a potential workaround depending on your needs.
Very comprehensive note on slicer. I haven't yet used ms excel 2010, but learnt Slicer tool very well
How should I apply Slicer in excel 2010 version, not able find options
as directed, could you please tell me that step by step
@Arif
In Excel 2010 slicers could only be applied to Pivot tables/Charts not Regular tables
@Arif
In Excel 2010 slicers could only be applied to Pivot tables/Charts not Regular tables
I have a longitudinal line graph with the count of exams scored at each level(1-4). I need a longitudinal line graph that shows the percentage for each level. I made my pivot with the count in the field settings with a calculation of % of row total. This works great until you add a slicer fo that you can look at one level at a time. When I do this, it shows as 100% because it seems to lose the rest of the row calculations. How can I set it up to show the percent. I do not have the option of adding it to my data table. I am using straight Pivot, not PowerPivot.
@Mary
I'd suggest asking the question in the Chandoo.org Forums http://forum.chandoo.org/
Attach a sample file with an example of what you are after, even hand drawn
Hi, thanks for these tips. Is it possible to link a slicer to *different data sets*? All my data sets have a "year_opened" and "month_opened" fields, and I'd like do a single filter and update everything at once. Is that possible?
Hi,
Can someone tell me how to format a date field in a slicer to tell July 2016 instead of 07/31/2016?
Thanks in advance.
Great post - easily explainable for non excel whiz.
Thanks for the slicers post. I'm knew to this feature so don't be to harsh on me 🙂
In the example bar chart graph: "Quantity breakup by Customer Profession and & Product category" you get a different picture depending on which area is chosen "East, Middle, North, South, West". That part I get. But the graph itself doesn't specify which region you are in.
Is it possible to put the filtered criteria into the Chart title. For example if I chose West, the title would read "Quantity breakup by Customer Profession and & Product category - West".
Is that possible? Just curious. Thanks
It is possible...I have this on a number of my reports.
1) create a pivot table with just the column your slicer is set on
2) assign the slicer to that pivot table
3) create a string in cell B3 (or wherever):
="Quantity breakup by Customer Profession & Product Category- "&A3
(assuming that A3 is the cell that the chosen region appears in)
4) click (once) on the graph title, then in the formula bar type =B3
As you change the slicers, B3 will update as will the chart title.
Couple of tips:
1) if you need to have a new line for the title, use CHAR(10) e.g.
="Quantity breakup by Customer Profession & Product Category"&CHAR(10)&A3
(this will have the region on a new line)
2) if multiple regions will be chosen, I've added in an IF statement
=IF(COUNTA(A3:A10)>1,"Multiple Regions",A3)
(I'm sure there are ways to concatenate the strings but for mine it could get up to 20 and that just gets ridiculous for the graph heading)
Just Wow
I am trying to create a duplicate dashboard using data in one workbook and creating a new workbook to place in a shared file for my coworkers. I have created a separate worksheet in the original workbook for the new pivot charts and slicers I want to use in the new workbook/dashboard. I don't want all of the source data in the new workbook, as it is very large. I am having trouble making new slicers work. They work in the original workbook, but when I copy them to the new workbook they don't work. Am I going about this the right way or is there an easier way?
Very good post! Helped a lot. Keep up the good work!
how can you prevent multiple selection in a slicer box? In short, in any slicer box, only one entry is allowed and not multiple entries.
Fairly new to forum's, hoping I'm not breaking a rule here, but I found this forum which seems to provide a solution:
https://wessexbi.wordpress.com/2014/03/17/just-one-slice-please/
I have 2 files. (1. .xlsx 2. .xlsm)
1 file contains all the pivot tables and charts. its also macro enabled.
2nd file contains the source data which is a .xlsx file.
but I am unable to run slicer on my 1st file.
can anybody help me out?
chandoo.org: one of my favourite Excel sites for years.
Slicers tutorial: excellent as usual.
Animated gifs: sorry, but REALLY distracting!! Especially with two on the same screen. Is there any way they can be activated only when we click on them, or something?
Hi Team,
I have inserted a slicer to a pivot table with 4 fields...I need to add another field for the same slicer...help me with this..
First of all I would like to say terrific blog!
I had a quick questio in whiich I'd like to ask if you don't
mind. I was intereested to know how you center yourself and clear your head
before writing. I've had a hard time clearing my mind in getting my ideas out there.
I do enjoy writing however it just seems like the first 10 to 15 minutes are generally lost simply just tryying to figure out how
to begin. Any recommendations oor tips? Many thanks!
Hi All
Im trying to connect a slicer to 2 pivot tables with different sources
Both data tables have been sorted and have duplicates
ie
Table 1
Name Week FTe
A 1 7.2
A 2 7.3
B 1 7.3
B 2 7.3
Table 2
Name Month Fte
A Jan 2.6
A Feb 3.2
A Mar 4.4
B Jan 2.2
B Feb 6.4
B Mar 2.2
etc
I have created 2 pivot tables and have sorted it out the way i want with charts etc
Now all i want is to connect the Name Slicer to be connected to both of those pivot tables but problem is they have duplicates and are from different tables/sources
how can i connect/add this to a data model and connect to my name slicer?
Im sure it maybe something simple but minds not with it
So in short 1 to connect 1 slicer to 2 different pivots from different sources but not all pivots (There are dups in both) - as shown in the example
Thank You
Hi H
This is how you can do it. Create a third table with all slicer options (in this case it would be Name column) with one row per unique value. Now add this table to your source list. Then link all two tables via this third table thru Data ribbon > Manage relationships feature. Finally add a slicer on this third table column and link the slicer to both pivot charts.
Please note that you need to construct the tables and charts after data model is created.
See this page for more explanation on how to use relationships - https://chandoo.org/wp/introduction-to-excel-2013-data-model-relationships/
Hi,
Using Cube Value with Slicers is great. I am new to cube value, but it is so powerful. I am stuck on an issue where I want to filter on a slicer for all values except 1 and the slicer has thousands of values. I get #N/A in the results, when trying to do this. Any ideas on how to do an exception calc or how to get around this with the multi select slicer functionality?
Thanks in advance.
Cyleste
@Cyleste... thanks for your comments and welcome to Chandoo.org. You can use DAX to calculate such things as Excel pivot tables alone cannot function like the way you want. You can use DAX formula EXCEPT() to achieve this. For example,
=CALCULATE(SUM(data[sales]), EXCEPT(ALL(data[filter_column]), VALUES(data[filter_column]))) can tell you the sum of [sales] column in the data table by ignoring slicer selected values.
Hope that helps.
Hi Chandoo,
Thank you for your quick reply. I am not familiar with DAX but it sounds like I won't be able to apply the calculation you provided after converting the power pivot to excel formulas via OLAP.
Cyleste
Thanks Chandoo, I like yours tricks & always I use slicers. Regards from México.
Hi Chandoo,
I have a lot of text in the slices (Pivot table). The text is not completely visible. What should I do?
Please Help
Thanks
Hi Girish,
Slicers are useful only for items with short text, for ex: categories, product names etc. For longer values, you are better off using form controls for interaction - Here is an overview of form controls Form Controls – Adding Interactivity to Your Worksheets
Thanks so much for this, it's brilliant! I think it's almost there - I've actually followed the steps on the example linked in my post. I just can't get it to filter properly; it just returns 0 when I add a date into Cell O2. Should I be doing it differently?
slicers dont work with non-admin roles in OLAP Pivot Tables