Process optimization of service-oriented automation devices based on Petri nets

Best paper award.This paper introduces a novel method for the specification and selection of criteria-weighted operation modes for the orchestration of services in industrial automation using Petri nets. The objective is to provide to the internal decision support system of a service-oriented automation device or of another applicable computational system the capability to select the best path in a Petri net orchestration model considering different criteria to evaluate the quality of services, such as the time, energy efficiency and reliability. The transition-invariants obtained from the Petri net represent the set of possible modi operandi and these are then weighted with decision criteria. The result will be afterwards evaluated in order to select the optimal modus operandi to be executed by the device. Based on the experiments, this method permits the dynamic optimization of processes in real-time, considering available parameters from devices and other resources.The authors would like to thank the European Commission and the partners of the EU FP6 project “Service-Oriented Cross-layer infrastructure for Distributed smart Embedded devices” (SOCRADES) and the EU FP7 project “Cooperating Objects Network of Excellence” (CONET) for their support

Analysis of Autonomic Service Oriented Architecture

— Service-Oriented Architecture (SOA) enables composition of large and complex computational units out of the available atomic services. However, implementation of SOA, for its dynamic nature, could bring about challenges in terms of service discovery, service interaction, and service composition. SOA may often need to dynamically re-configure and re-organize its topologies of interactions between the web services because of some unpredictable events, such as crashes or network problems, which will cause service unavailability. Complexity and dynamism of the current and future global network systems require service architecture that is capable of autonomously changing its structure and functionality to meet dynamic changes in the requirements and environment with little human intervention. In this paper, formal models of a proposed autonomic SOA framework are developed and analyzed using Petri Net. The results showed that SOA can be improved to cope with dynamic environment and services unavailability by incorporating case-based reasoning and autonomic computing paradigm to monitor and analyze events and service requests, then to plan and execute the appropriate actions using the knowledge stored in knowledge database. Keywords— Service Oriented Architecture, autonomic computing, case-based reasoning, formal model, Petri Ne

A High-level Petri Net Based Approach for Modeling and Composition of Web Services

AbstractWeb services are modular, self-describing, self-contained and loosely coupled applications, which intercommuni-cate via messages exchanging. The evolution of the internet and the emergence of new technologies like e-business have influenced the use of these last ones, which have become popular. The composition of web services is a topic that attracts the interest of researchers. It offers complex problems process ability even with simple existing web services while cooperating with each other. However, modeling tools and formal techniques for the completion of this task are required.In this paper, we show how simple existing web services can be composed, in order to create a composite service, which offers new features. In this context, we propose an expressive object-oriented Petri net based algebra that succeeds in the complex composition of Web services