Composition of Petri nets models in service-oriented industrial automation

In service-oriented systems, composition of services is required to build new, distributed and more complex services, based on the logic behavior of individual ones. This paper discusses the formal composition of Petri nets models used for the process description and control in service-oriented automation systems. The proposed approach considers two forms for the composition of services, notably the offline composition, applied during the design phase, and the online composition, related to the synchronization of Petri nets models on the fly. An experimental case study is used to illustrate the proposed composition approach.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

Toward synchronization between decentralized orchestrations of Composite Web Services

International audienceWeb service paradigm and related technologies have provided favorable means for the realization of collaborative business processes. From both conceptual and implementation points of view, the business processes are based on a centralized management approach. Nevertheless, it is very well known that the enterprise-wide process management where processes may span multiple organizational units requires particular considerations on scalability, heterogeneity, availability and privacy issues, that in turn, require particular consideration on decentralization. In a previous work , we have described a flexible methodology for splitting a centralized process specification into a form that is amenable to a distributed execution. The approach is based on the computation of very basic dependencies between process elements. In this paper, we extend this approach to support advanced patterns such as Loops, Multiple instances and Discriminator, and incorporate the necessary synchronization between the different processing entities. We also detail our interconnection mechanism and explain how to handle control and data dependencies between activities of the different partitions through asynchronous message exchanges. The proposed methodology preserves semantics of the centralized process with a peer-to peer interactions among the derived decentralized processes

A transformation-based approach to business process management in the cloud

Business Process Management (BPM) has gained a lot of popularity in the last two decades, since it allows organizations to manage and optimize their business processes. However, purchasing a BPM system can be an expensive investment for a company, since not only the software itself needs to be purchased, but also hardware is required on which the process engine should run, and personnel need to be hired or allocated for setting up and maintaining the hardware and the software. Cloud computing gives its users the opportunity of using computing resources in a pay-per-use manner, and perceiving these resources as unlimited. Therefore, the application of cloud computing technologies to BPM can be extremely beneficial specially for small and middle-size companies. Nevertheless, the fear of losing or exposing sensitive data by placing these data in the cloud is one of the biggest obstacles to the deployment of cloud-based solutions in organizations nowadays. In this paper we introduce a transformation-based approach that allows companies to control the parts of their business processes that should be allocated to their own premises and to the cloud, to avoid unwanted exposure of confidential data and to profit from the high performance of cloud environments. In our approach, the user annotates activities and data that should be placed in the cloud or on-premise, and an automated transformation generates the process fragments for cloud and on-premise deployment. The paper discusses the challenges of developing the transformation and presents a case study that demonstrates the applicability of the approach

Engineering of service-oriented automation systems: a survey

The evolution of manufacturing systems and the emergence of decentralised control require flexibility at various levels of their lifecycle. New emerging methods, such as multi-agent and service-oriented systems are major research topics in the sense of revitalizing the traditional production procedures. This paper takes an overview of the serviceoriented approach in terms of platform and engineering tools, from the perspective of automation and production systems. From the basic foundation to the more complex interactions, service-oriented architectures and its implementation in form of web services provide diverse and quality proved features that are welcome to different states of the production systems’ life-cycle. Key elements are the concepts of modelling and collaboration, which enhance the automatic binding and synchronisation of individual low-value services to more complex and meaningful structures. Such interactions can be specified by Petri nets, a mathematically well founded tool with features that enhance towards the modelling of systems. The right application of different methodologies together should motivate the development of service-oriented manufacturing systems that embrace the vision of collaborative automation.The authors would like to thank the European Commission and the partners of Network of Excellence “Innovative Production Machines and Systems” (http://www.iproms.org/) and the SOCRADES project (http://www.socrades.eu) for their support.info:eu-repo/semantics/publishedVersio

Engineering of service-oriented automation systems: a survey

The evolution of manufacturing systems and the emergence of decentralised control require flexibility at various levels of their lifecycle. New emerging methods, such as multi-agent and service-oriented systems are major research topics in the sense of revitalizing the traditional production procedures. This paper takes an overview of the serviceoriented approach in terms of platform and engineering tools, from the perspective of automation and production systems. From the basic foundation to the more complex interactions, service-oriented architectures and its implementation in form of web services provide diverse and quality proved features that are welcome to different states of the production systems’ life-cycle. Key elements are the concepts of modelling and collaboration, which enhance the automatic binding and synchronisation of individual low-value services to more complex and meaningful structures. Such interactions can be specified by Petri nets, a mathematically well founded tool with features that enhance towards the modelling of systems. The right application of different methodologies together should motivate the development of service-oriented manufacturing systems that embrace the vision of collaborative automation.The authors would like to thank the European Commission and the partners of Network of Excellence “Innovative Production Machines and Systems” (http://www.iproms.org/) and the SOCRADES project (http://www.socrades.eu) for their support.info:eu-repo/semantics/publishedVersio

Towards Distributed BPEL Orchestrations

Web services are imposing as the technology to integrate highly heterogeneous systems. BPEL, the standard technology to compose services, assumes a single âorchestratorâ that controls the execution flow and coordinates the interactions with selected services. This centralized approach simplifies the coordination among components, but it is also a too heavy constraint. To this end, the paper introduces the idea of distributed orchestrations and presents a proposal to couple BPEL and distributed execution in mobile settings. The approach âexemplified on a simple case studyâ transforms a centralized BPEL process into a set of coordinated processes. An explicit meta-model and graph transformation supply the formal grounding to obtain a set of related processes, and to add the communication infrastructure among the newly created processes. The paper also presents a communication infrastructure based on tuple spaces to make the different orchestrators interact in mobile contexts. Keywords: WS-BPEL, Grap

A flexible approach for automatic process decentralization using dependency tables

International audienceWeb service paradigm and related technologies have provided favorable means for the realization of collaborative business processes. From both conceptual and implementation points of view, the business processes are based on a centralized management approach. Nevertheless, it is very well known that the enterprise-wide process management where processes may span multiple organizational units requires particular considerations on scalability, heterogeneity, availability and privacy issues, that in turn, require particular consideration on decentralization. In this paper, our aim is to reconcile the decentralization of processes as a step towards the enterprise-wide solutions. We propose a methodology for transforming a centralized process specification into a form that is amenable to a distributed execution and to incorporate the necessary synchronization between different processing entities. The proposed technique has the advantage of being flexible that it computes the abstract constructs and provides a generalized approach to the decentralization of processes

On Evolving Partitioned Web Service Orchestrations

International audienceMany researches argue that centralized Web Service (WS) orchestrations stop short in dealing with key requirements such as scalability, privacy and reliability. Consequently, fragmentation and decentralization have been proposed to overcome these limitations. In detail, the centralized orchestration is fragmented into behaviorally equivalent distributed partitions such that their combined execution recreates the function of the original orchestration. However, the evolving nature of business processes as well as the necessity to adapt to market changes created the need for an efficient change support. Since the decentralization leads to the distribution of the activities, the control and data flows, it becomes difficult to specify the changes directly on the derived partitions. Therefore, it is more judicious to specify the changes on the centralized orchestration model and propagate the changes to the derived partitions. In this paper, we propose a comprehensive change framework for partitioned WS orchestration scenarios and demonstrate how to specify and propagate the changes from the centralized model to its resulting decentralized partitions. The main advantage of such an approach is that only partitions that are related to the specified changes are affected. There is no need to re-compute the whole orchestration and re-deploy all the distributed partitions