Veiga, Pedro Manuel BarbosaDomingos, Dulce2009-02-102014-11-142009-02-102014-11-142005-12http://hdl.handle.net/10451/14315http://repositorio.ul.pt/handle/10455/3120To meet their flexibility requirements, workflow management systems have been extended with a set of features that support process definition and process instances changes, while ensuring their correctness. These features impose new access control requirements, since they increase the number of objects and operations that need to be protected and require mechanisms to support access control changes. In this dissertation, we define an access control model that applies and extends the role-based access control reference model to adaptive workflow management systems. Considering the generality of this model, we apply it by interpreting the permission concept in terms of the objects and the operations that need protection. The extensions we propose aim to adapt the model to the peculiarities of adaptive workflow management systems, among which we point out the mechanisms that support access control changes and that ensure the correctness of process definitions and process instances. We also define an access control system that applies our model, which has been developed according to the abstract model of a reference monitor. By using the aspect-oriented programming paradigm we achieve the separation of the access control logic, as well as the isolation of the access control functionalities that are shared by other systems, promoting their reuse. Finally, we define guidelines to integrate access control into adaptive workflow based application process development, by using the information that business process models provide.porccess controladaptive workflowsworkflow management systemsrole based access controlaspect-oriented programmingsecure workflow based applicadoctoral thesis