Service orchestration with priority constraints

Business process management is an operational management approach that focuses on improving business processes. Business processes, i.e., collections of important activities in an organization, are represented in the form of a workflow, an orchestrated and repeatable pattern of activities amenable to automated analysis and control. Priority is an important concept in modeling workflows. We need priority to model cancelable and compensable tasks within transactional business processes. We use the Reo coordination language to model and formally analyze workflows. In this paper, we propose a constraint-based approach to formalize priority in Reo. We introduce special channels to propagate and block priority flows, define their semantics as constraints, and model priority propagation as a constraint satisfaction problem

Rule-Based Form for Stream Constraints

International audienceConstraint automata specify protocols as labeled transition systems that preserve synchronization under composition. They have been used as a basis for tools, such as compilers and model checkers. Unfortunately, composition of transition systems suffers from state space and transition space explosions, which limits scalability of the tools based on constraint automata. In this work, we propose stream constraints as an alternative to constraint automata that avoids state space explosions. We introduce a rule-based form for stream constraints that can avoid transition space explosions. We provide sufficient conditions under which our approach avoids transition space explosions

Soft constraint automata with memory

In this paper, we revise the notion of Soft Constraint Automata, where automata transitions are weighted and consequently each action is associated with a preference value. We first relax the underlying algebraic structure that models preferences, with the purpose to use bipolar preferences (i.e., both positive and negative ones). Then, we equip automata with memory cells, that is, with an internal state to remember and update information from transition to transition. Finally, we revise automata operators, as join and hiding

Extending paradigm with data

\u3cp\u3eWe discuss an extension of the coordination modeling language Paradigm. The extension is geared towards data-dependent interaction among components, where the coordination is influenced by possibly distributed data. The approach is illustrated by the well-known example of a bakery where tickets are issued to serve clients in order. Also, it is described how to encode Paradigm models with data in the process language of the mCRL2 toolset for further analysis of the coordination.\u3c/p\u3

Reo coordination model for simulation of quantum internet software

The novel field of quantum technology is being promoted by academia, governments and industry. Quantum technologies offer new means for carrying out fast computation as well as secure communication, using primitives that exploit peculiar characteristics of quantum physics. While building quantum computing devices remains a challenge, the area of quantum communication and cryptography has been successful in reaching industrial applications. In particular, recently, plans for building quantum internet have been put into action and expected to be launched by 2020 in the Netherlands. Quantum internet uses quantum communication as well as quantum entanglement along with classical communication. This makes design of software platform for quantum networks very challenging and a daunting task. Seamless design and testing of platforms for quantum software, thus, becomes a necessity to develop complex simulators for this kind of networks. In this short paper, we argue that using coordination models such as Reo can significantly simplify the development of software applications for quantum internet. Moreover, formal verification of such quantum software becomes possible, thanks to the separation of concerns, compositionality, and reusability of Reo models. This paper introduces an extension of a recently developed simulator for quantum internet (SimulaQron) by incorporating Reo models extended with quantum data and operations, along with classical data. We explain the main concepts and our plan for implementing this extension as a new tool: SimulaQ(reo)n

Slicing agent programs for more efficient verification

This is data related to the paper `Slicing Agent Programs for more Efficient Verification' published in the post-proceedings for the 6th International Workshop on Engineering Multi-Agent Systems (EMAS 2018). Specifically it contains the Prolog program used to slice a transformed Gwendolen Program and the logs of the verification runs used to evaluate the effectiveness of the proposed slicing method in reducing the state space for verification

On Multiplicities in Tuple-Based Coordination Languages: The Bach Family of Languages and Its Expressiveness Study

International audienceBuilding upon previous work by the authors, this paper reviews and proposes extensions of Linda-like languages aiming at coordinating data-intensive distributed systems. The languages manipulate tokens associated in different ways with a notion of multiplicity. Thanks to De Boer and Palamidessi’s notion of modular embedding, we establish expressiveness hierarchies. We also discuss implementation issues and argue that the more expressive the language is the more expensive is its implementation