Add to ORKGFunctional Size Measures are often used for effort estimation. However, these measures do not take into account the amount and complexity of elaboration required, concentrating instead on the amount of data accessed or moved. Methods for measuring the functional complexity have been proposed, but, being based on the textual description of requirements, are not very easy to apply. In this paper we show that measurement-oriented UML modeling can support the measurement of both functional size and functional complexity. We show, by means of a case study, that it is reasonably easy to derive different types of functional size measures, as well as complexity measures, from UML models. We show also that it is possible to build models for effort e...