Workbook Download
There are two zipped Excel Workbooks to go with this lesson
MICROSOFT EXCEL LEVEL 3
In this lesson we are going to look at two of the tools that are specifically
designed for use in "What-If analysis", and as such make up part of the
"What-If Analysis Toolpak of Microsoft Excel". These tools are used to
determine different outcomes of your data by changing different cells within a
Worksheet model. The two tools we will discuss here are called
Scenarios and Goal Seek. Both of these tools are used widely
in financial, accounting and engineering businesses today, and once understood
can be a huge aid in determining various outcomes and projections.
Scenarios are a very handy feature of Excel that are specifically designed for
use in "What if" analysis. A scenario is a specific set of values that
Excel can save for you and automatically substitute into your Worksheet.
This means that we can have a spreadsheet displaying numerical data that is
relevant to a certain date, month, topic or whatever and using the Scenario
Manager we can enter different values into the worksheet to forecast the
outcome of the data. These values (or scenarios) can be retained for
future use and are stored in a hidden part of the workbook which can be
retrieved by asking the Scenario Manager to show the Scenario that uses those
specific values.
Let's use an example to explain fully the function of Scenarios. We may
have a Worksheet that is predicting a Company budget for the next 12 months.
Our Managing Director has asked us to give an overview on what would happen if
company growth reached 15%, or decreased by 10% and what the outcome would be
if the wholesale cost of goods increased by 7% or decreased by 5%. You
can use Scenarios to "what if" test your Worksheet in a simple and logical
way.
Creating a Default Scenario
The very first thing that we must do is have an original or base model.
This will obviously be a Worksheet. The next thing we must do is to set up a base Scenario. Think of
it like a template or default Scenario. It is from this default
Scenario that all other Scenarios are defined.
Open the attached Workbook and ensure you are on the Worksheet 2002
Scenarios. Spend a few minutes familiarizing yourself with
it.
Go to Tools>Scenarios to activate the Scenario Manager. Notice
that as we have done nothing at this stage the Scenario Manager is telling you
that "No Scenarios are defined. Choose Add to add scenarios."
Let's do just as the Scenario Manager has instructed us to and click on Add.
This will bring up the Add Scenario dialog box and your cursor will be
flashing in the Scenario name: box to prompt you to firstly name
your scenario. In this box type Default Case as this is your
"template" or "original" data. Hit the tab key (or click with your left
mouse button if you prefer) and you will jump to the next box Changing cells:
You will notice here that the cell that was your active cell in the Workbook
will be referenced here. Click the collapse dialog button to collapse
this dialog box up so that you can easily select the cells from the Worksheet
that you wish to reference.
Highlight cells B4:B7 with your
mouse, then holding down your Ctrl key, click on cell B11, then
on E17. Click on the collapse dialog button again to expand the full
Scenario Manager box. If you wish to type a comment in, then click into
the Comment: box and do so now. This is a good point to mention the two
options at the bottom of this dialog box. They are Prevent changes
and Hide, with Prevent changes being the default. If you
select Prevent changes, then all your scenarios will be locked and will
be unable to be edited. It is important to note here that you MUST also
protect your Worksheet via the Tools>Protection>Protect sheet option
for this option to take effect. If you then with to edit your scenarios,
you must first unprotect your Worksheet, then de-select the Prevent changes
option to proceed. The Hide option when selected will do exactly
as said and Hide your scenarios. This option also requires sheet
protection for it to take effect. We will leave the default as
Prevent changes and make no other changes here.
Click the OK button. Once you click on the OK button the Scenario Values
dialog box will appear. This is where you must enter values into the
scenario cells. As this is our Default Scenario, the values in the cells
that we specified in the Changing Cells: box have been picked up so we need to make no changes here, we
need only click the OK button. This will now take us back to the
Scenario Manager and you will see the name Default scenario, the scenario we
just created.
Adding Scenarios
There is no limit to the number of scenarios that you can apply to your
worksheet model. Adding a scenario is done in basically the same way as
creating a default scenario. Let's add a Best Case Scenario and a Worst
Case Scenario and apply them to our model to really get the hang of how
scenarios can be used.
Select Tools>Scenarios to display the
Scenario Manager dialog box and select Add to display the Add Scenario
dialog box. Under Scenario name: type in Best Case.
We need make no changes to the Changing cells: box as the cells we
nominated in our Default scenario show here. Move to the
Comments: box and type in a short description such as Best case scenario
Jan 2002, then select OK. This will show the Scenario values
dialog box and this time we will change some values. Type 0.15 in 1,
type 0.1 in 2, type 0.05 in 3, type 0.045 in 4, 40,000 in
5 and 30,000 in 6. Select OK. Now we have two
scenarios available to us, our Default Scenario and our Best Case scenario.
Let's add the worst case scenario. Select Tools>Scenarios to display the
Scenario Manager dialog box and select Add to display the Add Scenario
dialog box. Under Scenario name: type in Worst Case.
We need make no changes to the Changing cells: box as the cells we
nominated originally in our Default scenario should still be showing here. Move to the
Comments: box and type in a short description like Worst case scenario
Jan 2002, then select OK. This will show the Scenario values
dialog box and we will add the following values. Type 0.05
in 1, type 0.06 in 2, type 0.025 in 3, type 0.020 in 4, type 30,000 in
5 and
20,000 in 6.
Using Names in Scenarios
Before we display and test the outcome of our model using the three scenarios
we have set up, let's take things a step further. The cells that we
selected to change in each of our three scenarios appear as cell references in
the Scenario values dialog box. It would be much easier for us and
for any other users of our Workbook if we could easily give names to these
cells and have them appear in lieu of cell addresses. This will make our
scenarios easier to read and understand and is a simple process.
Highlight the range A4:B7. Go to Insert>Name>Create to access the
Create Names dialog box. Make sure that Left column is selected and
click OK. Click in cell B11 and select
Insert>Name>Define and type in JanSales under Names in Workbook
in the Define Name dialog box. Finally, let's click on cell E17
and go to Insert>Name>Define and type in MajorImprovements under
Names in Workbook. Click on OK. Let's now make sure
that these names appear in lieu of the cell addresses in the Scenario Values
dialog box. Select Tools>Scenarios then click on any Scenario,
then select Edit then OK
to see the Scenario Values dialog box and the Names that we created.
Displaying Scenarios
Remember when we discussed Scenarios at the beginning of this lesson I stated
that a scenario is a specific set of values that Excel can save for you and
automatically substitute into your Worksheet. So in other words a scenario
is just a version of your worksheet with a specific set of values in place.
Now we have created three different scenarios, let's see how they change the
outcome of our data by asking the Scenario Manager to show a particular
scenario.
Select Tools>Scenarios click on Best Case, then click
Show. Drag the dialog box out of the way and have a look at the
values in the worksheet. One you have done this, click on Worst Case
then Show, again peruse the values in the worksheet, then finally select
Default Case and Show to have a look at your default scenario.
Click on Close when you no longer wish to view your scenarios.
Summary Reports
Excel will allow you to create a Scenario Summary Report or a Scenario
PivotTable Report of your scenarios with relative ease. The Summary Report
is always created on a new Worksheet within the Workbook and will list all of
the input cells and their values. Select Tools>Scenarios then click
on Summary to display the Scenario Summary dialog box.
Ensure that Scenario summary is selected under Report type then
select OK. Excel may or may not display the Result cells for you,
depending on which version of Excel you are using. You will be presented
with a Scenario Summary on a separate Worksheet within your workbook.
Creating a Scenario PivotTable report works in the same way, except you MUST
nominate your result cells for this type of report. As a tip, the quickest
and easiest way to do this is to go to Tools>Scenarios>Edit, highlight
any scenario, then select the cells under Changing Cells, select Ctrl
+ C, then select Cancel, then Summary then select Scenario
PivotTable Report, click in Result Cells, then select Ctrl + V
to paste in the values of the result cells. Select OK and your
Summary PivotTable Report will be presented to you on a separate Worksheet
within the Workbook.
Merging Scenarios
If you wanted to, you could bring in similar scenarios that
you have set up in different Workbooks into your current or active Worksheet.
This will only work however if the input cells are exactly the same as those
nominated in your current Worksheet. Merging scenarios can be
great for recycling and analysing a previous years set of figures with the
current year, or you may have different areas within a company that can make
use of the same scenarios. This can be done easily by following the
following steps.
Select Tools>Scenarios to again display the Scenario
Manager. Click on the Merge button and the Merge Scenarios dialog box
will appear. There are no changes to make in the first box as we wish to
use the current Workbook in this case. Let's go to the second box
Sheet: and highlight 2001 Scenarios. The next thing we do is
click OK, but note before you do this that you have a message at the bottom of
this dialog box telling you how many scenarios are in the source sheet that
you selected. In this case there are 3. Once you have clicked OK
you will be returned to the Scenario Manager and you should see the scenarios
from the 2001 Scenarios worksheet added to the scenarios from the 2002
Scenarios Worksheet. All that remains to do now is to test them.
So click on the various scenarios and click on Show to display them.
Remember, all that Scenarios are are just a different version
of the same worksheet with each different version using a different set of
input values in the nominated cells. Remember, to make your "What-if"
testing work correctly, you will need to remember to create your base model,
or default scenario so you can return to your "original" figures whenever you
need to.
GOAL SEEK
Goal Seek is the second
"What-If" analysis tool that we will discuss in this lesson. There
are many occasions in today's business world when we know the result of a
formula, but we do not know the input value the formula needs to determine the
result that we want to see. This is where Goal Seek comes in handy.
Goal seek asks the question "What will the value need to be in a particular
cell to arrive at a specific total? It then determines which part of
your formula needs to be changed in order to achieve the desired result.
As with Scenarios, we need to firstly set up a base model with which to
perform the Goal Seek. This base model needs to be set up in a Worksheet
with the data and formulas already in place and working. For Goal seek
to work correctly, you must identify on your base model:
-
The cell that contains the formula that you want to settle.
This is called the Set cell
-
The value you want the formula to change to. This is
called To value
-
The part of the formula that you wish to change. This is
called By Changing Cell
It is important to remember that
the Set cell must always contain a formula or a function,
whereas the Changing Cell must contain a value only. Not a
formula or function.
Let's say that we wish to borrow
money from the bank to modify and improve the existing canteen at our place of
work. We will use Goal Seek to calculate how the term of the loan will
be affected if we increase the Amount of our monthly loan repayments to
$6,000.
Open the attached workbook.
There is a formula in B7, which you will
need to type to get the result ($4,791.09). It is =PMT(B5/12,B4,B3). This
is calculating the monthly repayment of the loan.
It is always prudent to activate Goal Seek with
your mouse pointer clicked on the Set cell this is because our Set
cell will always contain the formula that we wish to settle. In our
example, cell B7 is our Set cell, because it contains the formula
calculating the monthly repayments of our loan.
With your mouse clicked in B7, select
Tools>Goal Seek to display the Goal Seek dialog box. Notice that as
soon as the Goal Seek dialog box appears on your screen, you will see a marquee
around the Set cell B7.
As we have already selected our Set cell, we
need make no changes in the first box. Click or tab to the To value:
box and type in -6,000. Click or tab to the final box By
changing cell: and select the collapse dialog button to the right of the box
to collapse the dialog box. Select cell B4 which is the term of the
loan in months. Note here that as soon as you click on B4, it becomes
absolute. Collapse back through to your dialog box and click OK.
As soon as you select OK you will see that Goal
Seek calculates a new term of the loan in the Worksheet. We have two
options now, OK or Cancel. If we select OK the new term will be inserted
into our Worksheet, of you select Cancel, the Goal Seek box will disappear, and
your Worksheet will be in its original state. Let's click Cancel and
perform a Goal Seek on our Worksheet to see what will happen to the Interest
Rate if we wished to repay $6,000.
Select Tools>Goal Seek to display the
Goal Seek dialog box again, ensuring that B7 is still your active cell.
Click or tab to the To value: box and type in -6000. Now click in
or tab to the By changing cell: box. This time we will select cell B5, as
it is the interest rate that we wish to change. Click on OK to see the new
interest rate that would be used if we repaid $6000 per month. This time,
let's select OK to accept the Goal Seek solution into our Worksheet.
So as you can seek Goal Seek is another of the
"What-If Analysis Tools" that can be performed on a Worksheet where you
can actually specify the end result that you want, then using this very handy
tool you can find out what the determining values need to be.