Enterprise Resource Planning (ERP) systems nowadays forms the infrastructure of many organisations worldwide. As business operating systems, they support the core business functions ranging from procurement over production, sales to accounting, cost management and human resource management. However, they hardly can cover the entire IT landscape and satisfy all individual requirements. Consequently, the efficient integration of ERP with legacy systems, other existing applications and best-of-breed solutions becomes a main success factor for benefits realisation. Further demand for ERP integration results out of the increasingly important design and implementation of collaborative solutions such as Supply Chain Management or Customer Relationship Management. While the area of ERP itself attracted significant academic interest, the actual integration of ERP solutions on the base of Enterprise Application Integration can be regarded as not sufficiently explored. However, the current interest in this topic is significant.