Processing by contract: Turning the wheel within heterogeneous workflow networks

Aims to show that workflow management needs to rethink its basis of discussion in order to meet today's challenges and to provide adequate IT support for heterogeneous workflow networks.

First, the need for flexibility in relating resources in workflow management is examined in more detail. Second, some approaches to managing workflows in heterogeneous networks are inspected and it is found that all of these improve flexibility on the basis of contracting services. Third, it is elaborated how processing by contract supports decentralized resource management through dynamically interrelating social and technical services driven by a cycle (“wheel”) of execution and monitoring, evaluation and demand, as well as selecting and contracting.

Conclusions are drawn for systems architecture and implementation to guide the design of internet‐enabled workflow support.

Important questions for the research agenda are: how can one enrich application‐oriented workflow modelling languages in order to describe processes as consisting of heterogeneous services? How should one design and implement workflow engines which enable the turning of the “wheel” with the support of integrating human activities and technical agency as workflow process services?

The idea of processing by contract may lead to new workflow concepts and technology to meet the challenges of an internet economy based on the “pay as you go” principle.

Whereas the workflow paradigm of the past may be phrased as processing by definition, i.e. process execution according to predefined process patterns and resource relations, the idea of processing by contract is suggested, i.e. a mode of process execution driven by recurrent process evaluation and service contracting.