Here is a tricky problem often faced by accountants and finance professionals: Let’s say you have 5 customers. Each of them need to pay you some money. Instead of paying the total amount in one go, they paid you in 30 small transactions. The total amount of these transactions matches how much they need to pay you. But you don’t know which customer paid which amounts. How would you reconcile the books?
If you match the transactions manually, it can take an eternity – after all there are more than 931 zillion combinations (5^30).
This is where solver can be handy. Solver can find optimal solution for problems like this before you finish your first cup of coffee.
Reconcile debits & credits using solver model – Tutorial
Step 1. Set up your solver model
In a blank sheet, list credits along a column and debits on the top in few columns, as shown below:
In the blank grid, Solver will fill 0 or 1 indicating whether credit in that row is matched with debit in that column or not.
This area is (C6:G35 in my workbook) is known as variable cell range in Solver model.
There are 2 rules to be followed when matching debits to credits:
- A credit can be matched with only one debit – ie sum of any row in C6:G35 range can be 1, at most.
- Total reconciled amount should be less than or equal to total credits – ie sum of any column in C6:G35 should be less than values in C5:G5 (debits).
To facilitate these rules, also known as constraints in solver parlance, let’s use column H & row 36.
- Write =SUM(C6:G6) in H6 and fill down the formula.
- Write =SUMPRODUCT($B$6:$B$35,C$6:C$35) in C36 and drag sideways to fill the formula in rest of the columns.
Our solver model should look like this:
Step 2: Set up optimization cell
To do its work, solver needs an optimization cell. Our goal is to maximize the amount of reconciled amount. So, in a blank cell write =SUM(C6:G36). This will be our optimization cell.
Step 3: Launch solver
Select the optimization cell (in my workbook, this is J6) and go to Data > Solver. (If you do not have solver, enable it using these instructions.)
Set up solver model as:
- Objective is to to maximize J6.
- Variable cells are C6:G35
- Constraints
- C6:G35 should be binary (o or 1)
- C36:G36 should be <= C5:G5
- H6:H35 should be <= 1
- Solver method is Simplex LP (our problem is linear)
When you are ready, Click Solve. Solver should take few minutes to find the solution.
Step 4: Examine the result
Once solver finds an answer, it will show Solver Results dialog. Click ok (you may also look at the sensitivity report). This loads the solver solution in to variable cell range.
Analyze the numbers and enjoy.
What if Solver solution is not optimum?
Occasionally, Solver fails to find optimum solution for linear problems with integer constraints. In such cases, try again by adjusting constraints & precision.
Download example workbook
Please click here to download the example workbook. Play with the solver model to learn more.
Other ways to reconcile data
If you deal with reconciliation problems, check out below examples to learn more:
- Match transactions using formulas
- Matching transactions using VBA macros
- Compare 2 lists using Excel conditional formatting
- Introduction to VLOOKUP formula – the easiest way to reconcile data
- Use SUMPRODUCT to consolidate revenues
How do you reconcile data?
Solver is a powerful way to reconcile data. It does take some time to set up the model and configure solver, but once your model is ready, Solver does all the heavy lifting.
What about you? What methods do you use to reconcile data? Please share your thoughts and tips in the comment section.
13 Responses to “Gantt Box Chart Tutorial & Template – Download and Try today”
Hi Chandoo
As one of your students I have followed your detailed example through with great success. However, Excel is acting in an unexpected way and I wonder if you could take a look?
http://cid-95d070c79aef808e.office.live.com/self.aspx/.Public/Gantt%20Box%20Chart.xlsm
On my version, I have to type 40239 (Which equates to 2 Mar 2010) to get the chart to display 31 May 2010 (which should be 40329)!!??
Have I done something wrong or is Excel acting up?
Thx
Oli
PS Your example file in 2007 displays correctly.
Hi,
I like this idea a lot, but I agree the name is a little drab.
As an American I may just be seeing things, but to me the combination of lines and bars on your chart looks like a bunch of cricket bats.
Maybe you could work that into a catchier name. 🙂
Cheers!
Here is some code I use to keep the axis synched.
It may be useful to some of your readers
It is based on a comment I saw on Daily Dose of Excel.
Function SynchGanttAxis(Cname, lower, upper)
'Sets the X min and X max for Category axis
Application.Volatile
On Error Resume Next
'
'Top Horizontal Axis
With ActiveSheet.Shapes(Cname).Chart.Axes(xlCategory, 1)
.MinimumScale = lower
.MaximumScale = upper
End With
'Bottom Horizontal Axis
With ActiveSheet.Shapes(Cname).Chart.Axes(xlValue, 2)
.MinimumScale = lower
.MaximumScale = upper
End With
End Function
Function SynchVerticalAxis(Cname, lower, upper)
Application.Volatile
On Error Resume Next
' Excel 2007 only
'Right hand vertical axis
With ActiveSheet.Shapes(Cname).Chart.Axes(xlValue, 1)
.MinimumScale = 0
.MaximumScale = upper
End With
End Function
@Oli.. Can you check your file again.. I see 40329...
@Dave: Even I saw things.. the bars actually looked like lollipops. How about calling this lollipop chart - now that would be yummy and goes along the tradition of naming charts after eatables (bar, pie, donut...)
@Bob: Superb stuff... thanks for sharing 🙂
Hi Chandoo
This looks really good and I think it can also be applied to show project phases / milestones.
Question: Thinking further could this be amended to display a project lifecycle (Idea through to Implementation say 7 phases) on one bar / row? Just imagine 20 projects within a programme all on one chart one bar each showing their respective lifecycle stages i.e. on one page.
Idea: As the Gantt Box Chart this is quite intensive to set up re formatting etc how about the added extra of once you have completed this to "Save as template" i.e. saves the formatting and layout of the chart as a template so you can apply to future charts. Simple to do and will save the time formatting etc again and again and again.
Therefore tip: Click on your chart demo and then click on Save As template icon (2007) - edit file name and click on save. Ready to use / apply via Templates in Change Chart Type window.
Thanks and be very interested if the lifecycle question can be resolved
Mike
How embarrassing.
I was obviously suffering from numerical dyslexia. I was one of those days.
@Mike H: You can easily make this chart to work like a generic project lifecycle plan chart. All you have to do is,
1. in a separate sheet define the steps of lifecycle and various dates in a table (with 5 columns for each of the projects you have).
2. now use a control cell to input the project name you want to show in the chart
3. based on the input, use OFFSET Formulas to get the correct data
4. Rest is same as the tutorial above
For more info on the dynamic charting visit http://chandoo.org/wp/tag/dynamic-charts/ and http://chandoo.org/wp?s=OFFSET
Your solution is really smart but in the en Excel isn't meant to do stuff like this. I, as a former PM, always thought is was frustrating that you had to do stuff like this for something simple like a Gantt chart. So I built Tom's Planner. And would like to plug it here. I think it really solves the problem you are trying to solve in the most efficient way. Check out http://www.tomsplanner.com for a free account or play around with the demo.
Hi there,
Chandoo - this is really a very nice and helpfull chart - I adopted it, so I can report a forecast or the delay of a certain task (coming from my role as an auditor for projects).
One topic I´m currently struggeling with: I do have a project lasting for lets say 12 month. For a management reporting, I want to have kind of snapshot, lets say one month back and 2 month in the future. I tried with the offset formula, but failed. Any idea?
Thx
Lopi
[...] Ein viel geliebter Klassiker ist die Erstellung von GANTT-Diagrammen mit Excel. Wir hatten das Thema wiederholt schon hier. Chandoo.org hat sich mal wieder mit einer neuen Variante hervorgetan: Das GANTT-Box-Chart. [...]
[...] [...]
Hi Chandoo - fantastic xls. One thing I can't figure out how to do is adjust the alignment of the vertical axis. I would like to left align so that I could indent to represent sub tasks. Can that be done? Or is there a better way?
I've been trying to work out if there's a way to show weekends on the graph. The closest thing I've got is to add them on a secondary axis, but then I haven't been able to keep both axis lined up together! Any ideas?
Following on from this - is it possible to show things like holidays?