Can function points be used for GUI based systems?
Yes. When the function point technique was originally developed, it was not applied to systems with Graphical User Interfaces (GUIs). There were no systems with GUIs! Even as late as three years ago, there was a certain amount of disagreement between function point practitioners regarding how to count these systems. Two years ago, IFPUG completed Release 4.0 of their Function Point Counting Practices Manual. It contains the official rules for, and extensive examples of, counting GUI based systems. Subsequently, IFPUG produced a case study that contained the count of an entire GUI-based system. Unfortunately, you can still find practitioners who are not familiar with the new rules and have not updated their course material to reflect current technology. Do not tolerate this! Just like any other professional you rely on, your function point specialist(s) should have knowledge that is up to date.
