Managing and estimating a good software is not an easy task. Because software estimation activities are concerned not only with time and effort scheduling, but also with specifying work activities, skill levels and scheduling of necessary resources. With duration, effort and other factors overlooked, poor reliability and functionality of software may occur. Furthermore, inaccurate estimation will lead to high pressure for the working team, and poor quality of final development. Hence, designing a right software metric is an imp ortant task. Due to these reasons, a software size model is being developed using a sample consisting of 122 student projects. This model takes several advantages: (1) there tends to be fewer counting problems than other software metrics, because this model is based upon simple counts; (2) the predicted software projects were calibrated to specific local environments rather than being based upon industry weights; (3) basic size components can be identified easily at the early stage of the development life cycle; (4) the model provides clues to project designers in planning and scheduling the development of new information systems.
Wu, Simon Iok Kuan, "The Role of Components of Data Flow Diagram in Software Size" (2003). ICEB 2003 Proceedings. 54.