An Algorand-based Approach for Flexible Execution of BPMN Choreographies

Blockchain technology has enabled secure and decentralized execution of inter-organizational business processes. Such processes define distributed interactions which can be designed using Business Process Model and Notation (BPMN) choreographies, encoded as smart contracts and executed in the blockchain. However, such processes may need to change at runtime to deal with unforeseen situations. This leads to the need for flexibility mechanisms, permitting the adaptation of the choreography specification and consequently the blockchain implementation. However, the immutability of blockchain poses challenges in this direction, as smart contract code typically cannot be updated once deployed. While some solutions as redeployment and patterns, are available, these introduce high costs and increased complexity. With the recent advent of the Algorand blockchain, intrinsic update capabilities are available, opening for novel solutions addressing flexibility needs. For this reason, we use Algorand to enable flexible execution of BPMN choreographies. Our approach modularly encodes choreographies as Algorand smart contracts, giving the means to allow and control runtime adaptation of the implementation. By changing the initial choreography, corresponding updates are reflected in the underlying smart contract, providing a novel solution that eliminates the need for complex gas-intensive patterns.