CS&E 1111 ExUnits

Effective Workbook Design for Large Problems

Effective Workbook Design for Large Problems

Objectives: Efficient/effective worksheet designs Using multiple worksheets in a workbook Using Split Screen & Freeze Pane features

for large worksheets Problem solving with “unit” conversions What-if analyses & Goal Seek

CS&E 1111 ExUnits

A Problem:A Problem:Your Gardening Nursery business is growing and you need additional help. You need to determine if you will save money by hiring temporary employees vs. two full time employees. You have the following information:

Temporary employees are paid $10/hour flat rate. You estimate you will need a total of 80 work hours a week for each of the 50 weeks you are open.

Each permanent employee works 40 hours per week and is paid $1000 per month plus benefits worth $5000 per year. Each receives 2 weeks paid vacation while your store is closed in January - so they are paid for a full 12 months. You will need a total of 2 permanent employees.

CS&E 1111 ExUnits

data inputs

calculations

output

Now Lets Implement This Problem in a Spreadsheet:A Single Worksheet Design Is

Best With Limited Quantities Of Data

By listing each input separately – it will be

easy to make changes without worrying about

where each value is used.

CS&E 1111 ExUnits

Designing a Spreadsheet SolutionUsing Multiple Worksheets

Designing a Spreadsheet SolutionUsing Multiple Worksheets

When creating spreadsheets with large amounts of related data it may be more effective to place each “table” of data in a separate location.

Excel provides us with the ability to have multiple worksheets within one workbook.

Sheet tabs

Sheets may be named and displayed with different colors tabs, The order of the worksheets may be modified as well.

CS&E 1111 ExUnits

input calc

A B C1 part time analysis full time analysis

2 wages= input!B7 * input!B6 * input!B5

= input!B1 * input!B2 * input!B8

3 benefits 0 = input!B1 * input!B34 total =B2+B3 =C2+C3

A B1 # FT emp 22 FT $/ month 10003 FT benefit/ year 50004 # weeks/ year 525 # weeks/ year open 506 PT $/ hour 107 PT hrs/ week 808 # months / year 12

Formulas

Syntax: Sheetname!Cell Reference• Formulas may include cell references from multiple

worksheets: input!B1*input!B3• When referencing a cell on the same spreadsheet as the

active cell the sheet name is not required. C2+C3• Named ranges are unique to a workbook. So if cell

input!B1 is named ‘employee’ the formula in cell C3 could be written as employee * input!B3

Referencing Cells on Multiple WorksheetsReferencing Cells on Multiple Worksheets

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input calc

1

2

3

4

A B C D

Part Time Costs Full Time Costs Differencewages $ 40,000 $ 24,000 (16,000)$ benefits $ - $ 10,000 10,000$ total 40,000$ 34,000$ (6,000)$

12345678

A B# FT emp 2FT $/ month 1000FT benefit/ year 5000# weeks/ year 52# weeks/ year open 50PT $/ hour 10PT hrs/ week 80# months / year 12

The results of both analyses are

presented on a single sheet

One method of organizing your data is with separate sheets for inputs, calculations and/or outputs. This

works well in the following instances:• Many different sheets share the same inputs – so each piece of

data need only be changed in one location• When you want to present the results only on a single sheet

comparing each of the different analyses

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Excel allows you to view multiple

worksheets on your screen

Excel allows you to view multiple

worksheets on your screen

1. If your worksheet is maximized

click on the Restore Window button.

2. Then size the window to easily view the contents of the worksheet using the sizing arrow from the edges of the window.

3. Open another window by selecting New Windows from the View Ribbon.

4. Select the next worksheet you desire to view and size it and place it on the screen so the contents is easy to view.

CS&E 1111 ExUnits

This works well when:•Different cases have different input values

•When you want to present the inputs/outputs and calculations of a single case on one sheet.

Another method of organizing workbooks is using separate sheets for different “cases”

Another method of organizing workbooks is using separate sheets for different “cases”

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Part Time Analysis Full Time Analysis Differencewages 128,000$ 88,800$ (39,200)$ benefits -$ 7,400$ 7,400$ total 128,000$ 96,200$ (31,800)$

All Stores

One advantage of using separate sheets for

different “cases” is the ability to easily create

summary sheets

One advantage of using separate sheets for

different “cases” is the ability to easily create

summary sheets

We can write a single 3-Dimensional Formula and then copy it down the column & across the row

=SUM(case1:case3!B12) or = case1!B12+case2!B12+case3!B12

case1!

case2!

case3!

CS&E 1111 ExUnits

Editing Multiple Worksheets SimultaneouslyEditing Multiple Worksheets Simultaneously

By holding down the Shift key we can select multiple worksheets simultaneously. When a [Group] is selected any changes made to a cell will be made to that same cell on all worksheets in that [Group]. To de-select a [Group] click on any worksheet not in the Group.

When multiple worksheets are selected the Title bar adds [Group] to the title.

Be careful when using groups not to inadvertently change something on another sheet that you didn’t want to.

CS&E 1111 ExUnits

Problems with Large Data SetsProblems with Large Data Sets

Consider a different example where you are analyzing a large dataset of gas prices.

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Split Screen, Freeze Pane and Hide Tools

Split Screen, Freeze Pane and Hide Tools

Split Screen creates sections that can each be independently scrolled.

Freeze Panes lets you freeze column and or row titles

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Sometimes its not just the organization of the worksheets – but equating “units” in our

problem solution

Sometimes its not just the organization of the worksheets – but equating “units” in our

problem solution

Land development: Acres Square Feet

Drapery fabric: Square Feet Square Yards

Nutrition: Grams of Fat Calories

Foreign Currency Exchange: Dollars Euros

Interest: Annual Percentage Rate Daily Rate

How do we mathematically convert units and how canExcel help us with this task?

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Consider another Problem:Consider another Problem:

You are a developer considering two adjacent pieces of property to purchase in order to construct homes on 10,000 SF plots. Which one is more cost effective cost per square foot?

$100,000 for 10 Acres

$120,000 for 40 10,000 SF plotsOR

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What information do you have?

What information do you have?

Option 1 Number of acres Total dollars 43,560 SF per acre

Option 2 Number of plots SF per plot Total dollars

Costs per SF

Costs per SF

What information do you need?

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Option 1 AnalysisHave: Number of acres = 10 Total dollars = $100,000

There are 43,560 SF per acre

If you are given number of acres, and total dollars and want $/SF what do you do?

acres * 43560 SF acre

10 = 435,600 SF

The same units in the

numerator & the

denominator cancel out

= .23 $/SF$100,000 ÷ 435,600 SF

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If you are given data in dollars and want dollars per square foot ($/SF) what do you do?

Option 2 AnalysisHave: Number of plots = 40 SF per plot = 10,000 Total dollars = 120,000

= $/Plot 300040 plots$120,000 ÷

plot10,000 SF

$3000

plot

When you divide, the denominator of a denominator

becomes the numerator or alternatively

multiply by 1 over the value

plot10,000 SF

$3000 plot

= $.30/SF

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Now you can add or subtract like units to compare Now you can add or subtract like units to compare

Option 1 Number of acres Total dollars 43,560 SF per acre

Option 2 Number of plots SF per plot Total dollars

.23 $/SF

.30 $/SF

Option 1 provides land at 7 cents per square foot less than the land in Option 2

.30 $/SF - .23 $/SF = .07 $/SFCompare Like

Units

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123456789

10111213

A B C D E F G

Option 1: Option 1:Price 100,000$ Price 120,000$ Quantity 10 acres Quantity 40 plots

Conversion Factors:43560 SF/acres 10000 SF/plot

Intermediate Calculations: Intermediate Calculations:#SF 435,600 $/plot 3,000$

Dollars per Square Foot: Dollars per Square Foot:0.23$ 0.30$

Land Development Cost Comparisondata inputs

output

Select a Single Worksheet Design Implementation

By listing each input separately – it will be

easy to perform what-if analyses

Intermediate

calculations

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Another Example:Which car is the best buy after 5 years? Car A costs $20,000 and gets 20 miles per gallon Car B costs $25,000 and gets 30 miles per gallon You can assume you drive an average of 12,000 miles per year and the

cost of gas is $4/gallon

Total Cost Purchase price + # years driven * Cost per year of gas

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To get cost per year of gas we need to calculate the number of gallons per year?

Miles MilesGallon Year

xMultiplying miles/gallon by miles/year results in miles2/gallon-year

Dividing miles/gallon by miles per year the result is years/gallon

Miles MilesGallon Year ÷

Miles Miles Year Gallon

Dividing miles/year by miles per gallon the result is gallons/year

÷

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Cancel like units in the numerator & denominator. Cancel like units in the numerator & denominator.

MilesYear

MilesGallon

GallonsYear

Units in the denominator of the denominator

become the numerator

GallonsYear

DollarGallon

DollarsYear

x

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Now complete the calculationNow complete the calculationTotal Cost Purchase price + # years driven * Cost

per year of gas

miles milesyear gallon

dollarsgallon

x÷Cost of the car + # years x

=B6+C$3*(C$1/C6*C$2)

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If you have an effective spreadsheet design – it is easy to create a What-if Analysis If you have an effective spreadsheet design – it is easy to create a What-if Analysis

Change one or more input values affected formulas are automatically recalculated

By Modifying the miles per year and number of years all cells based on that value are automatically changed.

CS&E 1111 ExUnits

Goal Seek allows us to determine an Input Value that would be needed to get a

Given Output

Allows us to work backwards in a worksheet Lets you vary only one input variable What-if analysis in the reverse direction.

Ex. What would the price of gas have to be to such that the total cost of the economy car (purchase + gas) is $30,000?

CS&E 1111 ExUnits

If we want the value in D6 to be $30000, what would the value in C2 ($/gal) have to be, assuming none of the other inputs change?

Goal Seek can be accessed from the Data Ribbon Tools Group

Goal Seek can be accessed from the Data Ribbon Tools Group

CS&E 1111 ExUnits

Design Your Worksheet:

Design Your Worksheet:

A simple example with very few options

The calculations for each option are different

Want to compare inputs as well as final output

Use a single worksheet design

A more complex example

Inputs are shared between options and do not vary independently

Input may contain large datasets

Inputs with complex calculations

Want to compare outputs only

Separate inputs & outputs onto different worksheets

A more complex example with multiple options

Calculations for each option are the same but input values vary

Want to compare inputs as well as final output

Place inputs/outputs for each case on a single worksheet in an identical design, then use a summary worksheet

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Some tips for designing your workbooksSome tips for designing your workbooks Think before “typing” –organize your data, determine

which inputs are likely to vary and which are fixed. Unless you have a very simple problem - consider

multiple worksheets for multi-table input/outputs or multiple cases.

Each data input should appear once and be used as a reference in subsequent calculations. Make sure you have correctly identified unit conversions and incorporated them into your solution

Document your workbooks - so that they can be easily understood by others