Data interoperability allows information sharing between different organizations, both public and private, for mutual benefits. This paper presents a case study providing an initial level of government data interoperability. SIGEVA is a set of applications for the management and evaluation of researchers and projects in the National Research Council (CONICET) in Argentina. The relevance of the case relies on promoting overcoming barriers in data exchange, although it exhibits several drawbacks. The case study is analyzed focusing in data interoperability; particularly in how to model a middleware to improve data interoperability between organizations with heterogeneous software applications. We show that data interoperability between organizations is a tendency to improve the activities of end-user, breaking down information silos. Furthermore, the solution requires to consider the levels of interoperability and barriers during the development process. Finally, in view of the detected problem, we propose a data interoperability solution with the properties of ensuring semantic consistency and overcoming heterogeneity.