Comprehensive Monitor-Oriented Compensation Programming

Compensation programming is typically used in the programming of web service compositions whose correct implementation is crucial due to their handling of security-critical activities such as financial transactions. While traditional exception handling depends on the state of the system at the moment of failure, compensation programming is significantly more challenging and dynamic because it is dependent on the runtime execution flow - with the history of behaviour of the system at the moment of failure affecting how to apply compensation. To address this dynamic element, we propose the use of runtime monitors to facilitate compensation programming, with monitors enabling the modeller to be able to implicitly reason in terms of the runtime control flow, thus separating the concerns of system building and compensation modelling. Our approach is instantiated into an architecture and shown to be applicable to a case study.Comment: In Proceedings FESCA 2014, arXiv:1404.043

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

Service-oriented SCADA and MES supporting petri nets based orchestrated automation systems

The fusion of mechatronics, communication, control and information technologies has allowed the introduction of new automation paradigms into the production environment. The virtualization of the production environment facilitated by the application of the service-oriented architecture paradigm is one of major outcomes of that fusion. On one side, service-oriented automation works based on exposition, subscription and use of automation functions represented by e.g. web services. On the other side, the evolution of traditional industrial systems, particularly in the production area, as a response to architectural and behavioural (functional) viewpoints of the ISA95 enterprise architecture, where a close inter-relation between SCADA, DCS and MES systems facilitate the management and control of the production environment. Automation functions are increasingly performed by the composition and orchestration of services. Among other methods, the application of formal Petri net based orchestration approaches is being industrially established. This paper presents the major characteristics that such a Petri net based orchestration presents when it is developed, implemented and deployed in an industrial environmentThe research leading to these results has received funding from the European Union's Seventh Framework Programme (FP7/2007-2013) under grant agreement 258682 (IMC-AESOP: ArchitecturE for Service-Oriented Process - Monitoring and Control) and 224053 (CONET: Cooperating Objects NETwork of excellence)

Recovery within long running transactions

As computer systems continue to grow in complexity, the possibilities of failure increase. At the same time, the increase in computer system pervasiveness in day-to-day activities brought along increased expectations on their reliability. This has led to the need for effective and automatic error recovery techniques to resolve failures. Transactions enable the handling of failure propagation over concurrent systems due to dependencies, restoring the system to the point before the failure occurred. However, in various settings, especially when interacting with the real world, reversal is not possible. The notion of compensations has been long advocated as a way of addressing this issue, through the specification of activities which can be executed to undo partial transactions. Still, there is no accepted standard theory; the literature offers a plethora of distinct formalisms and approaches. In this survey, we review the compensations from a theoretical point of view by: (i) giving a historic account of the evolution of compensating transactions; (ii) delineating and describing a number of design options involved; (iii) presenting a number of formalisms found in the literature, exposing similarities and differences; (iv) comparing formal notions of compensation correctness; (v) giving insights regarding the application of compensations in practice; and (vi) discussing current and future research trends in the area.peer-reviewe

Engineering framework for service-oriented automation systems

Tese de doutoramento. Engenharia Informática. Universidade do Porto. Faculdade de Engenharia. 201

Service-oriented control architecture for reconfigurable production systems

Evolvable and collaborative production systems are becoming an emergent paradigm towards flexibility and automatic re-configurability. The reconfiguration of those systems requires the existence of distributed and modular control components that interact in order to accomplish control activities. This paper focuses on service-oriented production systems, which behavior is regulated by the coordination of services that are provided and required by control components with different roles. Internally, these components are independent of the implementations, but an internal modular and event based structure is presented. Individual control and interaction is achieved by using embedded or inter-service control processes for which High-Level Petri Nets are proposed. Supporting the predefined control, decision support systems are used to provide conflict resolution and other decision-making functions

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

Engineering methods and tools for cyber–physical automation systems

Much has been published about potential benefits of the adoption of cyber–physical systems (CPSs) in manufacturing industry. However, less has been said about how such automation systems might be effectively configured and supported through their lifecycles and how application modeling, visualization, and reuse of such systems might be best achieved. It is vitally important to be able to incorporate support for engineering best practice while at the same time exploiting the potential that CPS has to offer in an automation systems setting. This paper considers the industrial context for the engineering of CPS. It reviews engineering approaches that have been proposed or adopted to date including Industry 4.0 and provides examples of engineering methods and tools that are currently available. The paper then focuses on the CPS engineering toolset being developed by the Automation Systems Group (ASG) in the Warwick Manufacturing Group (WMG), University of Warwick, Coventry, U.K. and explains via an industrial case study how such a component-based engineering toolset can support an integrated approach to the virtual and physical engineering of automation systems through their lifecycle via a method that enables multiple vendors' equipment to be effectively integrated and provides support for the specification, validation, and use of such systems across the supply chain, e.g., between end users and system integrators