A tuplespace based execution model for decentralized workflow enactment: applied for BPEL

The ability to cope with change is one of the biggest challenges companies arefacing today [JLN08]. Methods to increase business agility, such as outsourcingor off-shoring of non-core parts of the business are practiced already and willcontinue to play an important role in the future. A change in business howeveralways means to also change the underlying IT infrastructure, which thereforeneeds to be designed in a way to be able to support flexible re-arrangementof its support for business operations. IT systems today are integrated usingso called workflow management systems, that execute a business process inthe form of “orchestrations” of the individual applications used for carrying outbusiness functions.These processes today are enacted centrally, i.e. the workflow engine acts asa central point of control governing the lifecycle of all activities of a process.This way of enacting processes has certain drawbacks, revealed when executingchange such as outsourcing parts of a process. Using state-of-the-art workflowengines, this results in development of process partitions that need to bemaintained separately and were not created because the original business goalhas changed, but because the used workflow engine does not allow for flexibledeployment of a single process model to multiple process engines.This thesis proposes a fundamentally new execution model for decentralizedworkflow enactment that does not have these drawbacks. It allows for flexible