NPV and IRR in Execl/VBA

In our undergraduate Informatics II: VBA for non-IT students, class the financial indicator Net-Present-Value is programmed. This program also includes the counterpart, IRR, the difficulty of which also remains within the scope of this class. By the fourth semester, on which Informatics II is held, students have already taken the basic classes such as finance and statistics, so that no time needs to be used for conveying background information.

As IRR can have multiple values, one would have to start out with an initial guess. We take a value that would ensue from a too good to be true project: a version of our current project in which all the future cash flows occur at once (there is no discounting from the future) – thus purportedly overestimating IRR. We then start decreasing our estimation of IRR and at every step check whether we have arrived at a correct answer.