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ATI Course Schedule:

ATI's Engineering Systems

Modeling with Excel / VBA

Professional Development Short Course On:

Engineering Systems Modeling with Excel / VBA

Instructor:

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Description

These sample slides are excerpted from the 2-day short

course entitled “Engineering Systems Modeling with

Excel/VBA” The course provides in-depth details on the

Excel/VBA . The course provides in depth details on the

principles, practices, and implementation of Excel and its

integrated programming environment, Visual Basic for

Applications (VBA) for engineering analysis & modeling

Applications (VBA), for engineering analysis & modeling.

For upcoming public offerings of the course and other

p

g p

g

related information, please visit

www.aticourses.com

or

www.isothermtech.com

. To receive a monthly email

newsletter that includes Excel/VBA techniques & tips,

q

p ,

please send an email to

info@isothermtech.com

with

“Newsletter” in the subject field, and your contact

information in the body (a typical signature block is

sufficient).

(4)

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Course Summary

Thi

ill

id th

This course will provide the

knowledge and methods

to create custom thermal

& fluid system models

for…

¾

Analyzing conceptual

y

g

p

designs

¾

Performing system trades

¾

Simulating operation

¾

Optimizing system

performance

(5)

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Learning Objectives

• Exploit the full power of Excel for

building thermal & fluid models

• Master the built-in VBA

programming environment

• Implement advanced data I/O

• Implement advanced data I/O,

manipulation, analysis, and

display

• Create full featured graphical

interfaces and interactive content

• Optimize performance for

multi-parameter systems and designs

• Integrate interdisciplinary

capabilities into thermal & fluid

models

(6)

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Topics: Design & Build

1. Excel/VBA Review

2. Identifying Scope & Capabilities

3. Quick Prototyping

4. Defining Model Structure

5. Designing Graphical User

Interfaces

6. Building & Tuning the VBA

Engine

7. Customizing Output Results

8. Exploiting Built-in Excel

F

ti

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Topics: Refine & Optimize

9. Integrating External Data

10. Adding Interdisciplinary

Capabilities

11. Unleashing GoalSeek &

Solver

12. Incorporating Scenarios

13. Documentation, References, &

Li k

Links

14. Formatting & Protection

15 Flexibility Standardization &

15. Flexibility, Standardization, &

Configuration Control

16. Other Useful Tips & Tricks

p

(8)

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Modeling Options

B

ILITY

Finite element

CFD codes

A

VA

IL

A

B

Application

focused

d

Finite element,

finite difference

codes

T, LESS

A

Custom or

in-house

codes

E

R COS

T

in house

programs

Math computations

s/w (incl Excel/VBA)

HIGHER COMPLEXITY LOWER EASE OF USE

HIGH

E

Hand

calculations

(9)

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Advantages of Excel/VBA

FEATURES & BENEFITS

TECHNICAL APPLICATIONS

FEATURES & BENEFITS

• Flexibility & customization

• Built-in math functions

TECHNICAL APPLICATIONS

• Automating, standardizing,

& documenting repetitive

Built in math functions

• Data I/O, manipulation &

display

• Full featured GUI tools

g

p

calculations

• Performing what-ifs &

inverse solutions

• Rapid analytical

• Integrated programming

language & development

environment

• Multi-parameter solver

• Rapid analytical

prototyping

• Exploring conceptual

designs/systems

Multi parameter solver

• Ubiquitous installed user

base

• Familiarity & ease of use

• System trades and

parameter sensitivities

• Precursor, complementary,

and/or check for more high

• Interdisciplinary

capabilities (incl financial)

• Enable rapid exploration

of design variations

and/or check for more high

fidelity analyses

• Multidisciplinary

interactions (including

costing)

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Functions (Built-In)

• Excel has many useful

built-in functions under a

variety of categories

• These functions can be

invoked from the

worksheet side by

y

selecting a cell and

clicking the “fx” icon or

“Insert-Function…” from

th

b

the menu bar

• Many functions also exist

on the VBA side,

lth

h

th

t

although

the syntax may

be different (check the

VBA help menu)

Source: “Help - Microsoft Excel Help - Table of

Contents - Working with Data - Function Reference”

TIP: Worksheet side functions can be accessed in VBA by using the syntax:

“VBAvariable = Application.WorksheetFunction.FunctionName(Arg1, Arg2,….)”

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Graphics

• Objects can be placed

anywhere on the sheet

• Fill patterns & colors can be

added from the Drawing

toolbar

• When an object is selected,

When an object is selected,

editing circles appear

around the object and can

be used to size, rotate, or

th

i

dit th

bj t

otherwise edit the object

• “Connectors” can be added

that will follow the objects

j

wherever they move

TIP: To prevent a graphic from being changed when cells are re-sized,

right click on the graphic, select “Format Autoshape…”, select the

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Visual Basic Editor

Project

window

h

VBA

menu bar

includes

shows

workbook

objects,

userforms,

includes

debugger

and other

VBA

use o

s,

& modules

unique

picks

Properties

window

shows

Main

window

displays

shows

properties

of selected

object

displays

userform,

VBA code

modules,

j

etc.

(13)

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Project & Properties

Excel objects

(workbooks,

spreadsheets, etc.)

Userforms (see

blank one to the

right with toolbox

for adding controls)

Modules (This is

where the VBA

code is contained)

Properties of

selected object (a

THIS WINDOW DISPLAYS

WHATEVER VBA OBJECT

IS BEING EDITED (a

j

(

userform in this

case)

(

userform in this case)

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Functions vs Subs

Capabilities

Function

Sub

Capabilities

Function

Sub

Pass variables in

Yes

Pass variable out (incl array)

Yes

No

Modify worksheet objects &

No

Yes

Modify worksheet objects &

properties (incl cell values)

No

Yes

Call from a cell

Yes

No

Call from a cell

Yes

No

Run on an event (e.g. click)

No

Yes

Accessible as a user defined

function (“fx” icon)

Yes

No

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Object Structure

• Excel uses an object

oriented structure

• Objects can have a

ll

i

f

b bj

collection of sub-objects

(e.g.

Workbook-Worksheets-Range)

g )

• Properties define the

characteristics of an

object (e g Value)

object (e.g. Value)

• Methods are member

functions of the

li ti

bj t (

application object (e.g.

Activate)

• Events are actions that

can be taken on an

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Object Oriented Programming

• Virtually any “object” in the

Virtually any object in the

Excel environment can have

its properties accessed and

its methods executed using

the VBA Editor

– In the properties window

– With a sub procedure

• Properties can be read into a

variable by setting the

property equal to the variable

name

• Some properties can be

written to by setting the

property equal to a value or

variable

• Select “View-Object Browser”

and choose “Application”

NOTE: The scope of this course allows only a

limited introduction to this extensive topic.

_{and choose Application}

under Classes to see the

many objects that can be

limited introduction to this extensive topic.

Programming methods most applicable to

engineering models will be the primary focus.

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Putting Excel & VBA Together

Guidelines for integrating

Excel & VBA in thermal &

fl id

t

d l

• Use Excel as the interface

between the model and the user

fluid systems models:

between the model and the user

– Input & output management

– Decompose subsystems and/or

components in separate

worksheets

– Customize for intuitiveness &

performance

• Use VBA as the

numerical/algorithms engine:

– Calculations iteration decision

Calculations, iteration, decision

flow, loops, etc.

– Custom userforms

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Model Definition

• Who will be using the model?

– only the developer

– one well defined customer/user

END USER(S) &

CONFIGURATION

CONTROL

_{– user group}

– corporate wide distribution

– unlimited distribution

• What results do they need?

CONTROL

What results do they need?

– single point design

– design trades

– system simulation

t

ti i ti

SCOPE &

REQUIREMENTS

– system optimization

• What parameters do they want to vary?

– raw inputs

– statistical variations

CAPABILITIES

& INTERFACES

– design perturbations

• Who is developing the model?

– one person

2 or 3 people

& INTERFACES

STANDARDS &

– 2 or 3 people

– more than 10 people

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System Decomposition

S t

b

• Systems can be

decomposed in

Excel using

diff

t

different

worksheets

• If more than two

levels are needed,

can use the syntax:

1.1, 1.1.1, 1.1.1.1,

etc.

• Other Excel tools to

aid in documenting

and navigating

within system

models: Diagrams,

Navigation Objects,

and Outlines

NOTE: Can also add a parent level by creating

& linking multiple workbooks

(20)

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Start-Up Control

• The way a workbook is

y

displayed when it

opens can be

controlled

Open the VBA Editor

• Open the VBA Editor

• Double click on “This

Workbook” in the VBA

Project window

• Select “Workbook” in

the first drop down

window, and “Open” in

th

d

the second

• Add code to control

how the workbook

opens

The above code displays

a startup message,

_opens

• Other events can have

code attached by

selecting them from the

p

g ,

makes Sheet1 active,

zooms in to fill the

screen with columns A to

M and selects cell A1

_{second drop down}

g

menu (e.g. closing the

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Hyperlinks

To hyperlink an image or cell to a

target location:

1 Ri ht li k

th

l t d i

1. Right click on the selected image

or cell & select “Hyperlink”

2. Choose what type of link you

want to create and its location

(22)

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User Forms

• User Forms are created

User Forms are created

on the VBA side by

selecting

“Insert-U

F

”

UserForm”

• A Forms folder appears

in the Project window

containing a new

UserForm

• ActiveX controls can be

added by selecting them

and dragging on the

UserForm to place them

TIP: The name of the UserForm and all objects on it can be

(23)

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Scenarios

• Excel “Scenarios” tool

can be used to explore

p

and document changes

to system/design

parameters

• Can be automated with

VBA to add design

points with the push of

a button

• All named variables for

a given design can also

be output

(24)

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Sensitivity Analysis

• Analysis of the sensitivity

of various model

parameters can be done

quickly in Excel

• Use model to generate a

table of performance

results while varying one

parameter at a time

• Plot results to explore

sensitivity of performance

to key parameters

• A similar approach can be

used to investigate

process variability in

parameters (e g

parameters (e.g.

(25)

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Goal Seek

• Goal Seek is a

simple and easy

tool for finding a

desired value

based on changing

one variable

• Helpful for running

quick “what-if”

calculations

• Allows user to

explore design

boundaries as a

function of one

variable at a time

• Example: What flow

velocity will yield

the maximum

(26)

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Solver

S l

i

f l

• Solver is a very powerful

tool for multi-parameter

optimization

• Unfortunately

• Unfortunately,

documentation in Excel is

not comprehensive

• Can be run in real time or

Can be run in real time or

automated using VBA

• Note: must select

“VBA-Tools-References” and

check “Solver” if

automated (not covered

in this course)

• Is actually a third-party

add-in from Frontline

Systems

Man other 3

rd

_part

• Many other 3

rd

_party

(27)

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Interdisciplinary Models

Example of functions from one model:

• Excel is inherently

“blind” to the

discipline being

'PARTIAL PRESSURE OF WATER USING ANTOINE EQN

(AND DEW POINT) Function WaterPP(CellTemp)…

'VOLTAGE PER CELL

Function Vcell(CurrentDens,

Example of functions from one model:

d sc p

e be g

modeled

• This flexibility allows

the developer to

CellResist, RT_nFAnode, iOAnode, TafelSlopeCathode,

iOCathode, LimitingCurrent, Voc)…

'STRESS CALCULATION FOR WALL THICKNESS OF A

TANK Function WallT(units, material, pressure, diam,

the developer to

integrate other

technical disciplines

into the model

safetyfactor)…

'WALL THICKNESS CALCULATION FOR BUCKLING

LOAD (Refr: John F. Harvey, 1985) Function

BuckleThick(units, material, pressure, diam, length,

f t f t )

_{wherever and}

however is most

effective

safetyfactor)…

'SPHERICAL TANK INTERNAL SURFACE AREA Function

SphArea(diameter)…

'SPHERICAL TANK MASS Function SphMass(units,

• The interaction

between disciplines

is especially valuable

t

i

l t (

p

(

,

diameter, wallthick, material)

'HEAT LEAK INTO SPHERICAL TANK Function

SphHeat(units, diami, MLIfactor, area%, sinktemp, fluidtemp,

MLIlayers, foamthick, wallthick)…

to simulate (e.g.

“multiphysics”)

y

)

'ASSIGNMENT OF FLUID ID # FOR GASPAK

PROPERTIES Function FluidID(fluid)…

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Collaboration Lessons Learned

A

t

d li

t t

&

h

• Agree to modeling strategy & approach

upfront, and enforce it

• Insure all contributors have the skills to

implement adopted techniques

Subsystem 1

(Sheet1)

Subsystem 2

(Sheet2)

p

q

• If possible, have individual contributors

work on separate subsystem

worksheets

• Have a single person do system

integration of the workbook

• Implement configuration & version

control techniques

System

(Workbook)

• Consider using file storage &

management systems that “check-out”

documents to insure only one person is

working on it at any given time

g

y g

• Look to the “open source” development

community for more advanced

techniques (e.g. Apache, Linux, Open

Office, etc.)

Subsystem 3

(Sheet3)

Subsystem 4

(Sheet 4)

Office, etc.)

(29)

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Distribution & Version Control

• Use a version numbering

system to save

modifications

Development

Versions

– Development versions

can be saved as 1.1, 1.2,

1.3, etc. (archive these if

Versions

(e.g. 1.1, 1.2,…)

necessary)

– Released versions can

be saved as 1.0, 2.0, 3.0,

t (k

i

f th

Release for

Distribution

(e g 2 0)

etc. (keep copies of these

on hand for support

questions)

E

l

(e.g. 2.0)

• Examples

– ThermalModel_v2.5 is a

development version

Development

Versions

(e g 2 1 2 2

)

p

– ThermalModel_v3.0 is

the third release

(30)

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Exporting & Importing Modules

• VBA modules can

be exported to a file

for archiving or to

use for a library of

standard codes

Cli k

th

d l

• Click on the module

to be exported,

then select

“File-Export File…”

• The text file can be

imported into any

VBA module folder

by selecting

“File-I

t Fil

”

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Flexibility & Extensibility

• Excel is an ideal

environment for allowing

users to add custom

content to a standardized

model

• Some examples:

– Add price sheets

– Link model outputs to

custom calculations

– Provide worksheet sections

for user customization

– Allow addition of selected

macros

• By using the protection

settings, developer can

control which features to

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Index for Full 2-Day Course

TITLE SLIDE TITLE SLIDE TITLE SLIDE

ActiveX Controls 2003 148 Application: Multilayer Insulation 155 Cell Validation (cont.) 172

ActiveX Controls 2003 (cont.) 150 Application: Multilayer Insulation (c 156 Cells – Reading Data 209

ActiveX Controls 2007 149 Application: Multilayer Insulation (c 157 Cells – Writing Data 210

Add-Ins (Built-In) 35 Application: Multilayer Insulation (c 158 Collaboration Lessons Learned 238

Add-Ins (Custom) - Loading 243 Application: Multilayer Insulation (c 159 Command Guide 2003 to 2007 22

Add-Ins (Custom) - Saving 242 Application: Multilayer Insulation (c 160 Configuration Control 239

Advantages of Excel/VBA 14 Application: Simple Calc Sheet 28 Contents 3

Analysis ToolPak 2003 36 Application: SOTV Spacecraft 197 Contents 4

Analysis ToolPak 2007 37 Application: SOTV Spacecraft (con 198 Contents 5

Application: Another Calc Sheet 74 Application: SOTV Spacecraft (con 199( Contents 6

Application: Cryo Tank Design 214 Application: SOTV Spacecraft (con 200 Control Toolbox (cont.) 68

Application: Cryo Tank Design 215 Application: SOTV Spacecraft (con 201 Control Toolbox (cont.) 69

Application: Cryo Tank Design (c 216 Arrays - Creating 204 Control Toolbox 2003 66

Application: Fuel Cell 234 Arrays - Dynamic 208 Control Toolbox 2007 67

Application: Fuel Cell (cont) 235 Arrays – From Worksheet 206 Course Summary 7

A li ti H t L k 108 A I t 203 C Fit P i 132

Application: Heat Leak 108 Arrays - Intro 203 Curve Fits - Programming 132

Application: Heat Leak (cont) 109 Arrays – Passing in VBA 205 Curve Fitting - Continuous 118

Application: Heat Leak (cont) 110 Arrays – To Worksheet 207 Curve Fitting – Error Checking 126

Application: Heat Leak (cont) 111 Autofill & Absolute Refrs 30 Curve Fitting – Final Step 125

Application: Heat Leak (cont) 112 Basic Settings – Options 2003 26 Curve Fitting - Piecewise 127

Application: MEMS HX 179 Basic Settings - Security 2003 25 Curve Fitting Steps 2003 119

Application: MEMS HX 179 Basic Settings Security 2003 25 Curve Fitting Steps 2003 119

Application: MEMS HX (cont) 180 Basic Settings 2007 23 Curve Fitting Steps 2003 (cont.) 120

Application: MEMS HX (cont) 181 Buttons 151 Curve Fitting Steps 2003 (cont.) 121

Application: MEMS HX (cont) 182 Buttons (cont.) 152 Curve Fitting Steps 2007 122

Application: Microsystem 138 Cell Comments 170 Curve Fitting Steps 2007 (cont.) 123

Application: Microsystem (cont) 139 Cell Formatting 59 Curve Fitting Steps 2007 (cont.) 124

(39)

(isothermtech.com)

Index for Full 2-Day Course

Debugging Tools 89 Exercise 6: Pipe Design 212 Functions - Statistics 46

Description 2 Exercise 6: Pipe Design - Hints 213 Functions – Statistics (cont) 47

DESIGN & BUILD 107 Exercise 7: Optimize Pipe 232 Functions – Statistics (cont) 48

Distribution & Version Control 240 Exercise 7: Optimize Pipe - Hints 233 Functions – Statistics (cont) 49

Documenting Data & Refrs 133 Exercise 8: System Sheet 256 Functions – Text & Data 53

Documenting Data & Refrs (cont.) 134 Exercise 8: System Sheet - Hints 257 Functions - Using 39

Documenting Data & Refrs (cont.) 135 Exporting & Importing Modules 241 Functions - Using (cont.) 40

Equation Object 60 Flexibility & Extensibility 250 Functions (Built-In) 38

Equation Object - Installation 61 For & Do Loops 202 Functions (cont.) 82

Equation Object (cont ) 62 Form vs ActiveX Controls 70 Functions (cont ) 83

Equation Object (cont.) 62 Form vs ActiveX Controls 70 Functions (cont.) 83

Example : Electronics Cooling 249 Format for Printing 2003 251 Functions vs Subs 87

Excel + VBA 15 Format for Printing 2003 (cont.) 252 Getting Started with Excel 2007 21

Excel 2007 – New Features 16 Format for Printing 2007 253 Goal Seek 193

Excel 2007 VBA Changes 18 Function & Sub Tips 88 Goal Seek (cont.) 196

EXCEL REVIEW 27 Functions 81 Goal Seek 2003 194

Excel Size Limitations 17 Functions – Database & External 57 Goal Seek 2007 195

Exercise 1: Convection Sheet 71 Functions – Date & Time 56 Graphics - Manipulating 142

Exercise 1: Convection Sheet - Hints 72 Functions – Engineering 44 Graphics (cont.) 65

Exercise 2: Convection VBA 105 Functions – Engineering (cont) 45 Graphics 2003 63

Exercise 2: Convection VBA - Hints 106 Functions – Financial 50 Graphics 2007 64

Exercise 3: Fluid Properties 136 Functions Financial (cont) 51 Help Excel 2003 101

Exercise 3: Fluid Properties 136 Functions – Financial (cont) 51 Help - Excel 2003 101

Exercise 3: Fluid Properties - Hints 137 Functions – Financial (cont) 52 Help - Excel 2007 102

Exercise 4: Condenser 153 Functions – Information & Logical 55 Help - VBA 103

Exercise 4: Condenser - Hints 154 Functions – Lookup & Reference 54 Hiding & Locking Cells 246

Exercise 5: Properties Userform 175 Functions - Math 41 Hiding Rows & Columns 244

Exercise 5: Properties Userform - Hintsp 177 Functions – Math (cont)( ) 42 Hiding Worksheetsg 245

(40)

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Index for Full 2-Day Course

Hyperlinks (cont.) 147 Navigating Within Models (cont.) 168 Select Case 131

IF Statements 130 Navigating Within Models (cont.) 169 Sensitivity Analysis 192

Index 258 Number Formats 211 Solver 220

Index 259 Object Oriented Programming 95 Solver – Initial Use 2003 221

Index 260 Object Structure 94 Solver – Initial Use 2007 222

Index 261 Plots - Interactive 141 Solver – Loading Models 229

Instructor Bio 8 Programming Aids 90 Solver – Saving Models 228

Integration with Other Docs 254 Project & Properties 78 Solver - Settings 223

Interdisciplinary Models 237 Project & Properties (cont.) 79 Solver – Simple Example 224

Introductions 9 Protecting Sheets & Workbooks 247 Solver Simple Example (cont) 225

Introductions 9 Protecting Sheets & Workbooks 247 Solver – Simple Example (cont) 225

Learning Objectives 10 Protecting VBA 248 Solver – Simple Example (cont) 226

Macros - Editing 100 Prototyping – Calculations 116 Solver – Simple Example (cont) 227

Manual Digitizing 128 Prototyping – Inputs & Outputs 115 Solver - Tips 230

Manual Digitizing (cont.) 129 Prototyping – Last Step 117 Solver – Tips (cont) 231

Messagesg 143 Putting Excel & VBA Togetherg g 104 Some Mac Tips 19

Messages (cont.) 144 Recording Macros 2003 96 Start-Up Control 145

Model Definition 113 Recording Macros 2003 (cont.) 97 Strings (Characters) 255

Modeling Options 13 Recording Macros 2007 98 Sub Procedures 84

Modifying Excel Features 2003 218 Recording Macros 2007 (cont.) 99 Sub Procedures (cont.) 85

Modifying Excel Features 2007 219 REFINE & OPTIMIZE 178 Sub Procedures (cont.) 86

Modules 80 Reviving Legacy Excel Files 20 Summary Automation 188

Named Variables – Listing All 191 Scenario Summary 187 Summary Automation (cont.) 189

Names - Editing & Using 2003 33 Scenarios 183 Summary Automation (cont.) 190

Names Management 2007 34 Scenarios – Setting Up (cont.) 186 System Decomposition 114

Naming Cells & Ranges 31 Scenarios – Setting Up 2003 184 Systems Diagrams 236

Naming Many Cells 2003g y 32 Scenarios – Setting Up 2007g p 185 Topics: Design & Buildp g 11

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Index for Full 2-Day Course

User Forms 161

User Forms - Coding 162

User Forms – Coding (cont) 163

User Forms – More Controls 164

Userforms – Data Handling 165

Validation – Drop Down List 173

Variables - Declaring 91 Variables - Tips 93 Variables - Types 92 VBA Accessing 2003 75 VBA – Accessing 2003 75 VBA – Accessing 2007 76