This paper reports an empirical study that used computer science major students as experimental subjects to evaluate the productivity and the reproducibility of RmFFP. This is a functional size measurement procedure designed according to the COSMIC-FFP method for object-oriented systems that are specified using the OO-Method approach. The results show that the productivity of RmFFP is acceptable when compared to other procedures found in the literature. Furthermore, RmFFP produces reproducible functional size assessments.