Executable Models for Extensible Workflow Engines

Users and developers of workflow management systems are frequently confronted by changes in the application domains. Some of these changes cannot be adequately supported by existing workflow languages and engines, which makes it necessary to create new ones, or to adapt and extend some of the existing. However, there is a problem because usually these have limited capabilities to support evolution and adaptation, and there is a generalized lack of frameworks and libraries to support the development of new workflow engines, and of the associated and necessary tool chains (editors, clients, monitoring applications).This dissertation pro poses a platform, Cumbia, to serve as the foundation for workflow engines to run extensible and flexible workflow languages. With Cumbia it is possible to enact general purpose workflow languages (e.g., BPEL or BPMNJ, domain specific workflow languages (e.g., IMS-LD or SEDNA), and concern specific workflow languages which modularize workflow descriptions in accordance with various possible criteria. There are three central ideas behind Cumbia. This dissertation pro poses a platform, Cumbia, to serve as the foundation for workflow engines to run extensible and flexible workflow languages. With Cumbia it is possible to enact general purpose workflow languages (e.g., BPEL or BPMNJ, domain specific workflow languages (e.g., IMS-LD or SEDNA), and concern specific workflow languages which modularize workflow descriptions in accordance with various possible criteria. There are three central ideas behind Cumbia. Firstly, that of using metamodels to define the structure of workflow languages, and using models to represent specific workflows. Secondly, that of making the models executable by establishing executable semantics for every element in the metamodels, and following the semantics of the language. Finally, that of coordinating the execution of several executable models in order to support concern specific languages.