Towards Reusable Smart Contracts for Trustworthy Collaborative Processes (Discussion Paper) Ada Bagozi 1 , Devis Bianchini 1 , Valeria De Antonellis 1 , Massimiliano Garda 1 , and Michele Melchiori 1 University of Brescia, Dept. of Information Engineering Via Branze 38, 25123 - Brescia (Italy) a.bagozi@unibs.it, devis.bianchini@unibs.it, valeria.deantonellis@unibs.it, m.garda001@unibs.it, michele.melchiori@unibs.it Abstract. In collaborative environments, where enterprises interact each other’s without a centralised authority that ensures trust among them, the ability of providing cross-organisational services must be enabled also between mutually untrusting participants. Blockchain platforms and smart contracts have been proposed to implement trustworthy collabo- rative processes. However, current solutions are constrained to a spe- ciﬁc blockchain technology and deployed on-chain the whole process, thus increasing the execution costs of smart contracts on permissionless blockchains. In this paper, we propose an approach that includes criteria to identify trust-demanding objects and activities in collaborative pro- cesses, a model to describe smart contracts in a technology-independent way and guidelines to deploy them on a blockchain. To this aim, a three- layered model is used to describe: (i) the collaborative process, repre- sented in BPMN, where the business expert is supported to add annota- tions that identify trust-demanding objects and activities; (ii) Abstract Smart Contracts, based on trust-demanding objects and activities only and independent from any blockchain technology; (iii) Concrete Smart Contracts, that implement abstract ones and are deployed over a spe- ciﬁc blockchain. Flexibility and cost reduction brought by approach are discussed in the context of a case study on remote monitoring services for the digital factory. Keywords: blockchain, smart contract, collaborative processes 1 Introduction In collaborative environments enterprises provide cross-organisational services to deliver integrated oﬀerings of products and services, ensuring additional value Copyright c  2020 for this paper by its authors. Use permitted under Creative Com- mons License Attribution 4.0 International (CC BY 4.0). This volume is published and copyrighted by its editors. SEBD 2020, June 21-24, 2020, Villasimius, Italy.