Adapting Workflow Management Systems to BFT Blockchains -- The YAWL Example

Blockchain technology provides an auditable and tamper-proof distributed storage infrastructure for information records. This can be leveraged to support distributed workflow management. Compared to proof-of-work consensus, popularized by Bitcoin and Ethereum, blockchains based on BFT (byzantine fault tolerance) ordering consensus trade scalability for immediacy and finality of consensus. This makes them easier to use as distribution infrastructure, as applications need not be adapted to deal with eventual consistency and delayed consensus of proof-of-work blockchains. Hence, applications such as workflow engines can be easily ported to such a blockchain infrastructure to take advantage of their decentralized integrity assurance and information distribution model. In this paper we describe how the YAWL workflow engine can be used on a BFT based blockchain infrastructure to enable collaborative workflows across different organizations.