The continual enhancement of the requirements of a project as the system is being constructed. Scope creep occurs frequently in information systems development and is often responsible for going way over budget when the changes occur in the coding and testing stages rather than in the early design stages.

It seems to be the nature of humans to not be able to figure it all out at the start. Today's systems are exceedingly complex. Refinements often come during the latter stages, because users, analysts and programmers have gained more experience with the transactions and functions as well as the problems and initial solutions. "Rome wasn't built in a day!" See prototyping.