Time in Blockchain-Based Process Execution

TL;DR

This paper explores how to incorporate and measure time in blockchain-based process execution, addressing a key gap in current smart contract capabilities for managing deadlines and delays.

Contribution

It introduces a set of time measures on blockchain platforms and systematically compares their properties to support temporal constraints in process models.

Findings

Identifies limitations of current smart contracts in handling time.

Proposes a set of time measurement methods for blockchain platforms.

Provides guidance on selecting suitable time measures for process constraints.

Abstract

The traceable execution of business processes and choreographies using smart contracts is one prominent application of blockchain technology in Business Process Management (BPM). Existing approaches support a large set of patterns, modeling languages, and blockchain architectures, which cover a wide range of practical scenarios. However, they largely neglect the important aspect of time, a crucial part of process and choreography models manifested in deadlines, delays, and other temporal constraints. We argue that this deficit is due to inherent limitations of smart contracts---in particular the absence of a natural notion of measuring time---on popular blockchain platforms used in research and practice. We introduce a set of time measures available on blockchain platforms to alleviate these issues, and systematically compare their properties. We also give hints as to their suitability for facilitating various temporal constraints commonly found in process models.