Due to company mergers and business to business interoperability, there is a need for model transformations in the area of business process modeling to facilitate scenarios like model integration and model synchronization. General model transformation approaches do not consider the special properties of business process models and horizontal transformation scenarios. Therefore, we propose a model transformation approach based on domainspecific patterns which are applied for analyzing business process models in a precise way. This approach facilitates the definition of business process model transformations, which can be easily adapted to different business process modeling languages and specific transformation problems. At the same time it supports the intuitive understanding of the domainexperts in business process modeling.