A Trustworthy decentralized Change Propagation Mechanism for Declarative Choreographies

Blockchain technologies have emerged to serve as a trust basis for the monitoring and execution of business processes, particularly business process choreographies. However, dealing with changes in smart contract-enabled business processes remains an open issue. For any required modification to an existing smart contract (SC), a new version of the SC with a new address is deployed on the blockchain and stored in a contract registry. Moreover, in a choreography, a change in a partner process might affect the processes of other partners. Thus, the change effect must be propagated to partners of the choreography affected by the change. In this paper, we propose a new approach overcoming the limitations of SCs and allowing for the change management of blockchain-enabled declarative business process choreographies modeled as DCR graphs. Our approach allows a partner in a running blockchain-based DCR choreography instance to change its private DCR process. A change impacting other partners is propagated to their affected processes using a SC. The change propagation mechanism ensures the compatibility checks between public DCR processes of the partners. We demonstrate the approach’s feasibility through an implemented prototype.