Volatile market and legislative conditions impose constant changes on business processes, also demanding a change in the requirements set before information systems. As a solution to a situation in which the existing information systems cannot reach an adequate level of quality to keep up with the changes set up before them, user developed applications emerge, which are often developed in spreadsheet programs. Without questioning the benefits and utility of user developed applications in spreadsheet programs, practical experience nevertheless testifies to the consequences of errors in the development. The aim of this article is to give specific examples which draw attention to the seriousness of this issue and the need to introduce a framework for building and using user developed applications in spreadsheet programs.