The document describes an experiment to improve the accuracy of the COSMIC functional size measurement (FSM) method for early stage software projects. It uses a fuzzy logic model called EPCU, which considers two variables - the perceived size of use cases and number of related objects of interest - to estimate functional size. The experiment applied the EPCU model and traditional "equal size bands" approach to estimate sizes for 14 use cases. The EPCU model initially underestimated sizes but accuracy improved when expanding the output range, demonstrating its sensitivity to variable definitions. Further experiments are needed with more test cases to validate the approach.