The integration of heterogeneous systems is still one of the main challenges in the area of data management. Its importance is based on the trend towards heterogeneous system environments, where the different levels of integration approaches result in a large number of different integration systems. Due to these proprietary solutions and the lack of a standard for data-intensive integration processes, the model-driven development-following the paradigm of the Model-Driven Architecture (MDA)-is advantageous. This paper contributes to the model-driven development of complex and data-intensive integration processes. In addition, we illustrate optimization possibilities offered by this model-driven approach and discuss first evaluation results.