Rational Unified Process (RUP) provides a component-based development process which is use-case driven, architecture-centric, and iterative and incremental. This paper describes our experience of RUP application to the development of a web-based project management system, which had been peformed by a five-member team for one year. The paper introduces how we applied RUP in the development of the system and the difficulties we experienced over the course of the project. We tailored RUP by characterizing it in terms of six best practices and assigning a different priority to each of these. That is, the practice with the highest priority was primarily applied to the project. The paper then evaluates the performance levels of the performed project with respect to the tailored RUP in quantitative ways. The paper gives detailed analysis of the evaluation data to provide guidance for many small-team projects which adopt RUP.