Functional Size Measurement (FSM) methods are intended to measure the size of software by quantifying the functional user requirements of the software. The capability to accurately quantify the size of software in an early stage of the development lifecycle is critical to software project...

A number of Functional Size Measurement (FSM) methods have been proposed in the literature, but so far there has been no systematic evaluation of these methods. A major criticism is that little attention has been paid to the empirical validation of FSM methods. By empirical validation we refer...