Artificial Intelligence - Special issue on knowledge representation
Verification of workflow task structures: A petri-net-based approach
Information Systems
Analyzing process models using graph reduction techniques
Information Systems - The 11th international conference on advanced information systems engineering (CAiSE*
Constraint-directed techniques for scheduling alternative activities
Artificial Intelligence
Applying Propositional Logic to Workflow Verification
Information Technology and Management
Automatic Control of Workflow Processes Using ECA Rules
IEEE Transactions on Knowledge and Data Engineering
YAWL: yet another workflow language
Information Systems
Nested Precedence Networks with Alternatives: Recognition, Tractability, and Models
AIMSA '08 Proceedings of the 13th international conference on Artificial Intelligence: Methodology, Systems, and Applications
Handling alternative activities in resource-constrained project scheduling problems
IJCAI'07 Proceedings of the 20th international joint conference on Artifical intelligence
Executing reactive, model-based programs through graph-based temporal planning
IJCAI'01 Proceedings of the 17th international joint conference on Artificial intelligence - Volume 1
TAAI '11 Proceedings of the 2011 International Conference on Technologies and Applications of Artificial Intelligence
| Hi-index | 12.05 |
Workflows are used to formally describe processes of various types such as business and manufacturing processes. One of the critical tasks of workflow management is automated discovery of possible flaws in the workflow - workflow verification. In this paper, we formalize the problem of workflow verification as the problem of verifying that there exists a feasible process for each task in the workflow. This problem is tractable for nested workflows that are the workflows with a hierarchical structure similar to hierarchical task networks in planning. However, we show that if extra synchronization, precedence, or causal constraints are added to the nested structure, the workflow verification problem becomes NP-complete. We present a workflow verification algorithm for nested workflows with extra constraints that is based on constraint satisfaction techniques and exploits an incremental temporal reasoning algorithm. We then experimentally demonstrate efficiency of the proposed techniques on randomly generated workflows with various structures and sizes. The paper is concluded by notes on exploiting the presented techniques in the application FlowOpt for modeling, optimizing, visualizing, and analyzing production workflows.