Workflow and business process modeling approaches have become essential for designing service collaborations when developing SOA-based systems. To derive actual executable business process descriptions from the high-level workflow models, model transformation techniques can be used. Various service composition and business process languages are available for describing the executable processes....

The workflow satisfiability problem (WSP) asks whether there exists an assignment of authorised users to the steps in a workflow specification, subject to certain constraints on the assignment. (Such an assignment is called valid.) The problem is NP-hard even when restricted to the large class of user-independent constraints. Since the number of steps k is relatively small in practice, it is na...

ly, computational workflows may be understood as a directed acyclic graph (DAG), a kind of finite graph which contains no cycles and which must be traversed in a specific direction. In this representation, each node is an individual executable command. The edges in the DAG represent execution variables (data elements such as files or parameters) which pass from upstream nodes to downstream ones...

A print production workflow consists of a number of systems specialized at executing specific tasks. In order to realize an efficient workflow it is not enough to simply assemble all the required systems, the systems must also communicate with each other and exchange information. The printing industry has used several approaches for integrating systems. A common approach has been to use so-call...

to use services transparently in a distributed environment, the utility grids develop a cyber-infrastructure. the parameters of the quality of service such as the allocation-cost and makespan have to be dealt with in order to schedule workflow application tasks in the utility grids. optimization of both target parameters above is a challenge in a distributed environment and may conflict one ano...

A Self-Adaptive Recovery Net (SARN) is an extended Petri net model for specifying exceptional behavior in workflow systems. SARN caters for high-level recovery policies that are incorporated either with a single task or a set of tasks, called a recovery region. A recovery region delimits the part of the workflow from which the associated recovery policies take place. In this paper, we assume th...

Computer-based concept mapping learning environments can produce large amounts of data on student interactions. The ability to automatically extract common interaction patterns and distinguish between effective and ineffective interactions creates opportunities for researchers to calibrate feedback and assistance to better support student learning. In this paper, we present an exploratory workf...

In the Danish CLARIN-DK infrastructure, chaining language technology (LT) tools into a workflow is easy even for a non-expert user, because she only needs to specify the input and the desired output of the workflow. With this information and the registered input and output profiles of the available tools, the CLARIN-DK workflow management system (WMS) computes combinations of tools that will gi...

Providing reliable compositions of Web Services is a challenging issue since the workflow architect often has only a limited control over the reliability of the composed services. The architect can instead achieve reliability by properly planning the workflow architecture. To this end he must be able to evaluate and compare the reliability of multiple architectural solutions. In this paper we p...