Excel's Formula - sisman

Tools and Methods for
Debugging Formulas
In This Chapter
● What is formula debugging?
● How to identify and correct common formula errors
● A description of Excel’s auditing tools
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Errors happen. And when you create Excel formulas, errors happen very frequently. This chapter
describes common formula errors and discusses tools and methods that you can use to help create
formulas that work as they are intended to work.
Formula Debugging?
The term debugging refers to the process of identifying and correcting errors in a computer program.
Strictly speaking, an Excel formula is not a computer program. Formulas, however, are
subject to the same types of problems that occur in a computer program. If you create a formula
that does not work as it should, you need to identify and correct the problem.
The ultimate goal in developing a spreadsheet solution is to generate accurate results. For simple
worksheets, this is not difficult, and you can usually tell whether the formulas are producing correct
results. But as your worksheets grow in size or complexity, ensuring accuracy becomes more
difficult.
Making a change in a worksheet — even a relatively minor change — may produce a ripple effect
that introduces errors in other cells. For example, accidentally entering a value into a cell that
previously held a formula is all too easy to do. This simple error can have a major impact on other
formulas, and you may not discover the problem until long after you made the change — or you
may never discover the problem.