Structured Acyclic Nets
Mohammed Alahmadi, Salma Alharbi, Talal Alharbi, Nadiyah Almutairi, Tuwailaa Alshammari, Anirban Bhattacharyya, Maciej Koutny, Bowen Li, Brian Randell
TL;DR
The paper addresses generalizing structured occurrence nets to model complex evolving distributed systems by introducing acyclic net frameworks. It develops nine interrelated net classes, including acyclic nets (acnet), communication nets (CSAN), and behavioural nets (BSAN), along with variants like CSON and BDCSAN, and provides precise definitions of components, subnets, and cross-component buffers. Central contributions include well-formedness criteria and scenario-based semantics that connect structural and behavioral views, enabling projection and composition across components and ensuring deterministic causal histories where appropriate. This framework advances the analysis of multifaceted systems with synchronous/asynchronous communication, upgrades, reconfigurations, and failures, with potential for improved provenance, verification, and systems engineering.
Abstract
The concept of structured occurrence nets is an extension of that of occurrence nets which are directed acyclic graphs that represent causality and concurrency information concerning a single execution of a distributed system. The formalism of structured occurrence nets has been introduced to facilitate the portrayal and analysis of the behaviours, and in particular failures, of complex evolving systems. Such systems are composed of a large number of sub-systems which may proceed concurrently and interact with each other and with the external environment while their behaviour is subject to modification by other systems. The purpose of this paper is to provide an extension of structured occurrence nets to include models built up of acyclic nets rather than occurrence nets.