Spreadsheet Models for Managers

Getting Access to Spreadsheet Models for Managers

If Spreadsheet Models for Managersyou use Excel to model businesses, business processes, or business transactions, this course will change your life. You’ll learn how to create tools for yourself that will amaze even you. Unrestricted use of this material is available in two ways.

As a stand-alone Web site
It resides on your computer, and you can use it anywhere. No need for Internet access.
At this Web site
If you have access to the Internet whenever you want to view this material, you can purchase on-line access. Unlimited usage. I’m constantly making improvements and you’ll get them as soon as they’re available.

To Order On Line

Order "Spreadsheet Models for Managers, on-line edition, one month" by credit card, for USD 69.95 each, using our secure server, and receive download instructions by return email.
Order "Spreadsheet Models for Managers, on-line edition, three months" by credit card, for USD 199.00 each, using our secure server, and receive download instructions by return email.
Order "Spreadsheet Models for Managers, downloadable hyperbook edition" by credit card, for USD 199.00 each, using our secure server, and receive download instructions by return email.

To Order by Mail

Make your check payable to Chaco Canyon Consulting, for the amount indicated:
  • For the download: USD 199.00
  • For access online for three months: USD 199.00
  • For access online for one month: USD 69.95
And send it to:
Chaco Canyon Consulting
700 Huron Avenue, Suite 19C
Cambridge, MA 02138

To use the course software you’ll need some other applications, which you very probably already have. By placing your order, you’re confirming that you have the software you need, as described on this site.

Spreadsheet Models for Managers

What is modeling? 1/25
Session Links
  • Modeling is the art of simulating a system or process
  • Faithful models exhibit behavior analogous to the systems they model
  • Models usually have validity with respect to a particular domain
  • The value of a model is determined by
    • Model-based costs
      • Development — how easy is it to change or enhance?
      • Maintenance — how easy is it to keep current?
      • Training — how easy is it to learn or explain to others?
      • Use — how easy is it to use
    • Cost of examining the system directly (without a model)
    • Fidelity — how good are its predictions?

Modeling truly is an art, because the modeler must make decisions about what to include and what to omit. Often, these decisions cannot be made systematically — there is no concise set of rules that tells you what parts of a system to include in your model and what parts to ignore. For this reason, people and organizations who know how to design useful models have a competitive edge.

Most of the models people build are static models. That is, they simulate a property of a system that doesn’t change over time. For example, we can make a model of a fast-food drive-through that tells us how long the driveway has to be, given the average service time, the average length of a car, and the average arrival rate of customers. See Problem 12.1, and the readings on models.

Dynamic models, on the other hand, make predictions about system attributes that vary with time. For example, we can make a model of a business that predicts the number of sofas in inventory through the year, given expected demand and the requirements for ordering. See Problem 3.1.

In your course project, you’ll be building a dynamic model. Be very certain that you understand the difference between the two types of models. See Course Project.

Last Modified: Wednesday, 27-Apr-2016 04:15:26 EDT

Deciding What to Read

The first homework assignment has a fair amount of reading attached to it. Some students feel that the best approach is to read it all, and then try to do the homework. For most of us, such an approach doesn’t work very well.

Before you begin the course, read the general material, such as “Getting Started,” “Software You Need for This Course,” and “How to Work.”

Later, as you begin the homework, let the homework drive your reading choices. For instance, the first homework assignment does require that you master certain techniques. Read “Names” and “The Ripple Principle.” Then, if something confuses you, read up on it: examples are “The Basics of Recalculation” and “References.” Learning something when you need it, and only when you need it, is usually the best way to go.

Avoid Redundant Parentheses

Parentheses sometimes make a real difference. For instance A1*B1+2 is very different from A1*(B1+2). But A1*(B1*2) is exactly the same as A1*B1*2. When the parentheses don’t make any difference in the value of the result, it’s not usually a good idea to include them. They tend to make the formulas harder to read, and there’s always the chance that you’ll put them in the wrong place. More