On the other hand CR may go from low or moderate to high, which means that you can't rely on controls after all. So, the main point of all this is that there are various decision points along the systems evaluation and testing path, any one of which may result in you abandoning your study of the particular accounting system. We looked quickly at the answers to the review questions over 'tea'. If you are comfortable with these questions and answers, you've understood the main points of this topic. Also, there's the issue in complex, integrated systems of one transaction causing instantaneous updating of many different accounting records.
Complexity is certainly an important issue.
Easy to understand, doesn't require much technical know-how, and can lead you up the garden path unless the system is very simple. Also, assumes inputs and outputs are in human-readable form. We'll look at some of these in more depth in a week or two. However, with respect to tests of controls, we mentioned the test data approach and the integrated test facility. There's also parallel testing and other methods, which I failed to mention but which you can read up for yourselves in the textbook.