Effective test cases are critical to the success of a development effort but their creation requires large amounts of critical resources such as domain expertise. This study explores an approach to automating test case definition in the context of applying a model driven approach to the development of a software product line. In this study, test cases are automatically extracted from use cases, which are specified using a domain specific language (DSL). DSLs are easier for domain experts to use than formal specification languages and are more narrowly focused than natural languages making it easier to build tools. The task is further simplified by restricting the DSL to the scope of the software product line under development. The structure of the DSL and proven patterns of test design provide the clues necessary to be able to automatically extract the test cases. A chain of model-driven tools is used to automate the system test process, which begins with a use case model and ends with automatic execution of system tests.