Thesis (MTech. degree in Business Information Systems.)--Tshwane University of Technology, 2009. / Software projects often fails due to poor estimates. These estimation problems often involve the under- or over-estimation of costs, the duration of the project and the complexity of the system. Project estimation comprises one of the major aspects of project management which either makes or breaks a project. Accordingly the aim of this research is to identify estimation problems, their causes and their impact on the success or failure of projects. The results indicated that the majority of the participants developers and clients have experienced estimation problems in certain of the IT/software projects that they have either implemented or developed. These problems have tended to impact negatively on the outcome of the projects. Based on the research findings and on suggestions from various participants, recommendations are made that could assist the developers and clients of software/IT projects to prevent these estimation problems. Accordingly these recommendations could contribute to more successful projects.