In a previous project (see "Prototyping with Scenarios and Contracts") we focused on how to support Design by Contract for various programming language and how to provide elementary tool support. In the meantime the Object Constraint Language (OCL) is part of the Unified Modeling Language (UML). Besides other application areas in the UML realm, the OCL can be used to specify contracts in a Design by Contract style. In this project the emphasis is to support the specification of OCL contracts throughout the entire software development life cycle, i.e., from analysis to testing (with Java-based projects in mind). The emphasis of the project is on tool development for a contract centered software development process and on gaining empirical evidence of the impact of contracts on the software quality.