A Practical Approach for Reliable Pre-Project Effort Estimation

Precise estimation is an important foundation for accurate project planning and staffing. However, state of practice methods (such as Function Points) typically require a thorough elicitation and analysis of system requirements, which is usually not available in an early project phase or even before a project begins. Use Case Points (UCP) are a possible solution for this dilemma and hence, in this paper we explain how a practically successful approach that combines UCP with COCOMO-based estimation can help to derive more accurate estimates. Moreover, we discuss how these estimates can be based on minimal “use case briefs” that allow estimation with less upfront effort than their “fully dressed” variant. The presented approach is thus applicable on a rudimentary understanding of requirements and helps to reduce the investment necessary for effort estimations before or soon after project initialization. Moreover, it is applicable by both, the customer as well as the IT service provider.