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.
Or order via Google Checkout.
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.
Or order via Google Checkout.
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.
Or order via Google Checkout.

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 11J
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.

Subscribe now!

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.
Or order via Google Checkout.
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.
Or order via Google Checkout.
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.
Or order via Google Checkout.

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 11J
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


Session 3
Cushioning, Crowding, and Quantization
Summary of Pages


Since modeling is inherently inexact, we sometimes build into our models a safety margin. We call this cushioning. The contrary practice of planning to overtax resources is called crowding. In business modeling, there are occasions when both cushioning and crowding are valuable techniques. Quantization is the effect we observe in models when the values of some of the model parameters are restricted to lie in bands, or when they must adhere to specific values. For example, the practice of ”staircasing“ price schedules produces quantization effects in expense or revenue models.

Excel provides some facilities that are useful in all these situations, and we’ll explain them and illustrate their use. Cushioning, crowding and quantization can lead to complex and confusing models, but if you’re systematic about how you handle these effects, your models will be simpler and easier to maintain.

One effect that appears in complex models is usually an error — the circular reference. We’ll talk about circular references, and how to unwind them.

Below is a summary of pages for Session 3.

  1. Lasttime
  2. Why conservative modeling?
  3. Cushioning
  4. Crowding
  5. Quantization
  6. Computational issues
  7. Excel functions for cushions, crowding, and quantization
  8. Modeling techniques for cushions
  9. Circular reference errors
  10. Unwinding circular references
  11. Unwinding circular references, continued
  12. Implicit intersection
  13. Cautions about implicit intersection
  14. The main points
  15. Preview of Next Time

Links to other materials for Session 3.

Last Modified: Wednesday, 09-Apr-2014 04:48:23 EDT

Understanding Implicit Intersection

Implicit Intersection is one of the most underrated — and at the same time one of the most powerful — techniques in all of Excel. Yet few people truly understand it.

Implicit Intersection is the method by which one cell can retrieve a value from another range by examining the intersection of its row (or column) with that range. If the intersection is unique — a single-cell — then the formula of the cell that depends on implicit intersection can update its value without incident. If not, an error results.

Terminology for Worksheet Functions

When talking about worksheet functions, it’s important to be careful about your choice of terminology. Technology is like that, and like it or not, Excel is a piece of technology.

Cells can have formulas, as we’ve seen, and those formulas can invoke worksheet functions. Cells do not contain functions — rather, they can contain formulas, which, in turn, can invoke one or more worksheet functions.

User-defined names are not functions.

To invoke a worksheet function in the context of a cell formula, one calls a worksheet function. Often, you hear this described as “applying a worksheet function.” Do not use that terminology. For example, we’ll speak of “calling a function on its arguments,” or “calling a function with its arguments.” We do not say that we “apply a function to its arguments.”

When Excel calculates the value of a cell, and that cell’s formula contains a call to a worksheet function, that function call is evaluated. Its value is then returned to the formula, which uses it, in turn, to compute its own value.

Sometimes you hear worksheet functions referred to as commands. They aren’t commands. Commands are found on Excel’s menus, or perhaps in some dialog boxes. Commands do things, like format a cell, or sort a range. Commands don’t return values — functions return values.