Among the maintainability sub-characteristics, changeability plays a critical role in analyzing the maintainability of software. Changeability is highly influenced by the dependencies that exist between the components of a system. Therefore, we need to have measurement mechanisms that can take into account the dependencies between components so as to determine the ease which modifications can be made to given software. This paper attempts to investigate the usefulness of three coupling metrics (CBO, Ce, and Ca) and one size/complexity metric (WMC) as predictors of changeability. The assessment is based on a case study of open source software known as OpenBravoPOS which is commonly used in the retail business and developed in Java. The results show that some of the coupling metrics can be used as good predictors of changeability.