The Model-Driven Architecture (MDA) technology toolsetincludes a language for describing the structure of meta-data, the MOF,and a language for describing consistency properties that data must exhibit,the OCL. Off-the-shelf tools can generate meta-data repositoriesand perform consistency checking over the data they contain. In thispaper we describe how these tools can be used to implement runtime requirementsmonitoring of systems by modelling the required behaviourof the system, implementing a meta-data repository to collect systemdata, and consistency checking the repository to discover violations. Weevaluate the approach by implementing a contract checker for the SLAngservice-level agreement language, a language defined using a MOF metamodel,and integrating the checker into an Enterprise JavaBeans application.We discuss scalability issues resulting from immaturities in theapplied technologies, leading to recommendations for their future development. The Model-Driven Architecture (MDA) technology toolsetincludes a language for describing the structure of meta-data, the MOF,and a language for describing consistency properties that data must exhibit,the OCL. Off-the-shelf tools can generate meta-data repositoriesand perform consistency checking over the data they contain. In thispaper we describe how these tools can be used to implement runtime requirementsmonitoring of systems by modelling the required behaviourof the system, implementing a meta-data repository to collect systemdata, and consistency checking the repository to discover violations. Weevaluate the approach by implementing a contract checker for the SLAngservice-level agreement language, a language defined using a MOF metamodel,and integrating the checker into an Enterprise JavaBeans application.We discuss scalability issues resulting from immaturities in theapplied technologies, leading to recommendations for their future development.