Workflow Management on Proof-of-Work Blockchains: Implications and Recommendations

Abstract

Blockchain technology, originally popularized by cryptocurrencies, has been proposed as an infrastructure technology with applications in many areas of business management. Blockchains provide an immutable record of transactions, which makes them useful in situations where actors must cooperate but may not fully trust each other. In this paper, we examine the use of proof-of-work blockchains for executing inter-organizational workflows. We discuss architectural options and describe two prototype implementations of a blockchain-based workflow management system (WfMS), highlighting differences to traditional WfMS. Our main contribution is the identification of potential problems raised by proof-of-work blockchain infrastructure and recommendations to address them.

Applications of Blockchain in Business Processes: A Comprehensive Review

“…The weakness to the approach is the state distinction, (discussed later in section VI). The works introduced by Härer [58] and Evermann and Kim [43] take an alternative way with the belief that smart contracts are not the only way to enable trust of BP executions. They notice that the translation of BPs into smart contracts incur unnecessary cost and error prone.…”

“…The role of BC is to track workflow instances, assuring the state of work and indicating next valid activities, such that integrity of model execution is preserved. Evermann and Kim [43] advance the work by implementing a workflow engine directly on BC and introducing standard interfaces to interact with BC infrastructure. The implications between traditional and BC-based WfMS are identified through experiments with several design choices.…”

“…However, the adaptation ability lessens the tamper-proof as it allows changes to be made at runtime [53] (L3). A solution presented by Evermann and Kim [43] uses a technique by generating all possible outputs and changes are simply done by relocating BC heads. However, it suffers resource waste as all combinations must be precalculated.…”

“…From existing literature, BP changes can be done in two ways: (1) generating outputs by anticipating all possible changes to support undo operations [43] and (2) triggering changes by adding high-level consensus using smart contracts [82]. For example, a voting mechanism can be implemented by smart contracts as an upper layer consensus to commit changes; this offers flexibility in the changes of partners and their associated tasks [73,156].…”

Addressing Scalability Issues in Blockchain: A Use case from Healthcare

“…It requires exchanging information with other similar entities/parties to arrive at a consensus. It is important that the Consensus Protocol implemented must also be suitable for certain blockchain type that has the framework and purpose for which the blockchain is used [9], [12]. Some of the major Consensus Protocols are discussed below:…”