Constraint-based workflow management systems : shifting control to users

Many organizations use information technology to support various aspects of their business processes: the operational aspect, collaboration between employees, etc. Workow management systems aim at supporting the operational aspect of complex business processes by using process models to automate the ordering of activities (i.e., ow of work). The term `support' here relates to the ability of workow management systems to control the execution of business processes. Contemporary workow management systems lack exibility, i.e., the system controls in detail how employees should execute business processes. While work- ow management systems deal well with predictable business processes, they are not able to handle unforeseen situations, which occur often in real-life business processes. Although employees mostly have the knowledge and experience that enables them to deal with exceptional situations, they are not able to apply the right action because the system enforces the standard procedure of work. This often has various undesired consequences: work is done `outside' the system, work cannot be done in the appropriate way, dissatisfaction of employees, resistance towards the system, etc. As a result, workow management systems cannot be used properly if it is necessary that employees control the execution of business processes. This thesis proposes a new approach to workow management systems that can facilitate contemporary business processes in a better way by enabling a better balance between exibility and support. As opposed to traditional approaches which use procedural process models to explicitly (i.e., step-by-step) specify the execution procedure, the proposed approach aims at the specification of business processes using constraints, i.e., processes are modeled by rules that should be followed while executing business processes. Constraint-based models implicitly specify the execution procedure by means of constraints: any execution that does not violate constraints is possible. In addition to proposing a constrainbased approach, a concrete language for specification of constraints is given and the proof-of-concept prototype declare is described. On the one hand, constraint-based management systems are exible, which allows employees to deal with specific (e/g/. unpredicted) situations in the most adequate way. On the other hand, constraint-based management systems can support employees when it comes to aspects of business processes that are too complex for humans to handle. There are several ways in which constraintbased management systems can provide both exibility and support.