Information system development is an expensive process, and usually fall behind the expectations of user and implementation is achieved much later than expected if ever. The designers of information systems and programmers often begin designing and programming the system too early, before they actually understand the users' or stakeholders' requirements. Since designing and programming systems are very expensive, ill-defined requirements cause projects to fall behind schedule and over budget. Correctly assessing customer needs and requirements is very important for information systems development. Over 50% of development errors occur during the requirements analysis phase of the development cycle.