A MVC Framework for Policy-Based Adaptation of Workflow Processes: A Case Study on Confidentiality

Most work on adaptive workflows offers insufficient flexibility to enforce complex policies regarding dynamic, evolvable and robust workflows. In addition, many proposed approaches require customized workflow engines. This paper presents a portable framework for realistic enforcement of dynamic adaptation policies in business processes. The framework is based on the Model-View-Controller (MVC) pattern, commonly used for adding dynamism to web pages. To enhance reusability, our approach supports separation of adaptation logic from the functional workflow and modularization of workflow tasks in reusable aspects. The main idea is to design a workflow process as a template, where tasks can be specified on an abstract level. Concrete implementations of the tasks, modeled as aspects, are then selected from a library according to a policy-based adaptation logic. This logic is implemented using a general purpose language that offers an extensible and flexible solution to enforce any type of policy. We evaluate by means of a case study on workflow confidentiality to what extent an approach using standards-based technologies allows application-specific adaptation of running workflow instances.