Development of Incremental Integration Tools Using Formal Specifications M. Lefering The integration of documents is one of the key problems in software engineering today. This paper presents an approach for integrating documents that were created in different phases of the lifecycle by using integration tools. These tools execute a transformation algorithm that is expressed by a transformation rule set. They are based on a generic framework that can be reused for new prototypes without modifications. Formal specifications of transformations that support various integration scenarios can be derived automatically out of specifications for the related documents and the definition of correspondences between the productions of these specifications. Three prototypes for integration tools according to this scenario have been developed.