Département Informatique

Computer Science Department of Telecom SudParis

New paper “Trustworthy Cross-Organizational Collaborations with Hybrid On/Off-Chain Declarative Choreographies” at ICSOC’2021

Authors: Tiphaine Henry, Amina Brahem, Nassim Laga, Julien Hatin, Walid Gaaloul and Boualem Benatallah


Business Process Management communities increasingly adopt the blockchain technology to support trustworthy decentralized execution of processes. In this context, the interest in business process choreographies rises as they offer a distributed way to compose and control cross-organizational processes. In choreographies, the process view is distributed between participants to limit privacy leakages. Hence, the process observability (i.e., who knows what) is challenging. On one side, partners have no insight into each other’s orchestration and communicate peer-to-peer via the public view. On the other side, they have to maintain their internal orchestrations’ states consistent with the choreography’s global state. The need to ensure a privacy-preserving method to enforce a blockchain-based execution thus rises. In the present work, we propose a unified solution for the hybrid on/off-chain generation and execution of business process choreographies. The public view, shared understanding of the cross-organizational process, is triggered by the on-chain smart contract. Participants generate their private views off-chain using this on-chain public view. They execute afterward the private views in their off-chain process execution engine. Our prototypical implementation demonstrates the feasibility of the approach .

PhD thesis defense of David Oudart on May 7 2020: “Model driven engineering applied to Smart Grids design: Cosimulation with FMI approach”

Model driven engineering applied to Smart Grids design: Cosimulation with FMI approach


Smart Grids are cyber-physical systems that interface power grids with information and communication technologies to monitor them, automate decision making and balance production with consumption. We want to use simulation to easily evaluate and compare several solutions before deployment in a real environment. The objective of this thesis is thus to propose tools and methods to model and simulate a Smart Grid in an industrial context. We have identified two main issues: How to combine heterogeneous models of a Smart Grid to simulate it? How to ensure consistency between the models produced by different stakeholders during the design of a Smart Grid? To address these issues, we propose a cosimulation approach, using the Functional Mockup Interface (FMI) standard. Our first two contributions are the proposal of a method to allow the exchange of discrete signals between several FMUs, and an extension of the OMNeT++ telecommunications simulation software implementing this method, called fmi4omnetpp. A third contribution is the development of the Smart Grid Simulation Framework tooled environment, which automates a number of repetitive tasks in order to ensure consistency between different simulation models. Finally, a fourth contribution is the formalization of an iterative design approach for the cosimulation of a Smart Grid, and how to integrate our Smart Grid Simulation Framework into it. To do so, we explain the different steps of the approach and the role of the actors involved in the design process, then we present its application to a real case study for which we use our Smart Grid Simulation Framework.