Smart Contracts’ Upgradability for Flexible Business Processes

Business process execution and support by blockchain-based systems have received increasing interest, particularly in applications where execution trace immutability and independent verifiability are needed. Recent approaches to automatically convert business process models into smart contracts have significantly streamlined blockchain support for business processes. However, the dynamic nature of business processes requires services to be adaptable to evolving conditions, activities, agreements, or regulations. Subsequent adaptation of the corresponding smart contracts is also a must. Adoption of so-called business process change patterns into smart contracts is not straightforward, as smart contracts cannot be modified once deployed. Further, smart contract upgradability patterns are not designed with business process applications in mind. In this paper, we present an approach to assess and select the most suitable smart contract upgradability pattern for a given business process change pattern, based on six software quality metrics. Moreover, we provide an assessment of the preferred upgradability patterns for each change pattern using the presented approach.