Authors
David Colver
Abstract
Inclusion analysis is the name given by Operis to a black box testing technique that it has found to make the checking of key financial ratios calculated by spreadsheet models quicker, easier and more likely to find omission errors than code inspection.
Sample
One approach for improving the chance that a spreadsheet delivers the results that it is intended to deliver is to calculate quantities two or more different ways. If independent methods produce identical answers, there is a good chance, though no guarantee, that those answers are trustworthy.
An obvious example concerns a table of numbers. The table has rows totals, column totals, and a grand total. It therefore offers opportunities to calculate the table total four times over.
There are some simple things that ought to be the case. To pick just two:
- SUM(R) = SUM(C).
- SUM(A)= G * 4.
Since these tests are trivial to code, a conscientious spreadsheet developer will include them as a matter of course.
Publication
2007, EuSpRIG
