Translating semantic web service based business process models

We describe a model-driven translation approach between Semantic Web Service based business process models in the context of the SUPER project. In SUPER we provide a set of business process ontologies for enabling access to the business process space inside the organisation at the semantic level. One major task in this context is to handle the translations between the provided ontologies in order to navigate from different views at the business level to the IT view at the execution level. In this paper we present the results of our translation approach, which transforms instances of BPMO to instances of sBPEL

SYMEX: A Systems Theory based Framework for Workflow Modelling and Execution

Workflow management systems enable organisations to deal with all aspects of business process management, including analysis, modelling, execution, and administration. Modelling workflow processes involves transformation of the process logic into a formal representation and it always remains a critical success factor for these systems. Workflow modelling languages provide constructs for capturing high-level descriptions of business processes, which are then have to be transformed and encoded into low-level execution semantics with the use of workflow programming languages. However, maintaining these models separately results in a number of issues, particularly when the various interdependencies between them are managed manually. This primarily creates difficulties in adaptation, in terms of identifying changes in high-level descriptions due to modifications of business conditions, and tracing the impact of those changes on the low-level execution semantics. Moreover, certain information included in the high-level descriptions is either partly encoded or omitted from the low-level execution semantics and at the same time, complicated business rules encoded at the execution level are not included in the high-level descriptions, creating major inconsistencies. The above issues result in high maintenance costs, reducing the overall efficiency and performance of workflow management systems. This thesis addresses the aforementioned problems by proposing a framework named SYMEX. SYMEX addresses the issue of integrating high and low-level descriptions in one unified format, from a Systems Theory perspective. SYMEX models have a mathematically defined formalism capable of capturing both high-level descriptions of business processes and low-level workflow execution semantics. Furthermore, SYMEX offers a concise and easy to learn and communicate set of constructs, allowing business analysts, process designers, and programmers to work on the same model, at different levels of abstraction. Apart from the theoretical framework, an XMLbased approach for the application of SYMEX is proposed, along with a constraint- based inference engine. Additionally, SYMEX models are evaluated in terms of their complexity and prove easier to read, understand, and manage than other traditional workflow modelling approaches. However, further research is required to assess the capability of the framework, with respect to modelling workflow processes in a service-oriented environment, where activities of business processes are essentially web-services exposed on the Internet

An Integrated Methodology for Creating Composed Web/Grid Services

This thesis presents an approach to design, specify, validate, verify, implement, and evaluate composed web/grid services. Web and grid services can be composed to create new services with complex behaviours. The BPEL (Business Process Execution Language) standard was created to enable the orchestration of web services, but there have also been investigation of its use for grid services. BPEL specifies the implementation of service composition but has no formal semantics; implementations are in practice checked by testing. Formal methods are used in general to define an abstract model of system behaviour that allows simulation and reasoning about properties. The approach can detect and reduce potentially costly errors at design time. CRESS (Communication Representation Employing Systematic Specification) is a domainindependent, graphical, abstract notation, and integrated toolset for developing composite web service. The original version of CRESS had automated support for formal specification in LOTOS (Language Of Temporal Ordering Specification), executing formal validation with MUSTARD (Multiple-Use Scenario Testing and Refusal Description), and implementing in BPEL4WS as the early version of BPEL standard. This thesis work has extended CRESS and its integrated tools to design, specify, validate, verify, implement, and evaluate composed web/grid services. The work has extended the CRESS notation to support a wider range of service compositions, and has applied it to grid services as a new domain. The thesis presents two new tools, CLOVE (CRESS Language-Oriented Verification Environment) and MINT (MUSTARD Interpreter), to respectively support formal verification and implementation testing. New work has also extended CRESS to automate implementation of composed services using the more recent BPEL standard WS-BPEL 2.0

Quality of (Digital) Services in e-Government

Internet growth in the nineties supported government ambition to provide better services to citizens through the development of Information and Communication Technologies based solutions. Thanks to the Lisbon conference, which in 2000 covered and investigated this topic, e-government has been recognized as one of the major priorities in Public Administration innovation process. As a matter of\ud fact in the last 10 years the number of services provided to citizens through Information and Communication Technologies has increased rapidly. Nevertheless the increasing rate, the access and usage of digital services do not follow the same trend. Nowadays Public Administrations deliver many electronic services which\ud are seldom used by citizens. Different reasons contribute to the highlighted situation.\ud The main assumption of the thesis is that quality of e-government digital services strongly affects real access to services by citizens. According to the complexity of quality in e-government, one of the main challenges was to define a suitable quality model. To reach such aim, domain-dependent characteristics on the services delivery have been investigated. The defined model refers to citizen,\ud technology and service related quality characteristics. Correspondingly a suitable way to represent, assess, and continuously improve services quality according to\ud such domain requirements has been introduced.\ud Concerning the service related quality aspects a methodology and a tool permitting to formally and automatically assess the quality of a designed service with\ud respect to the quality model has been defined. Starting from an user friendly notation, both for service and quality requirements, the proposed methodology has\ud been implemented as an user friendly tool supported by a mapping from user friendly notations to formal language. The tool allows to verify formally via model checking, if the given service satisfies one by one the quality requirements addressed by the quality model.\ud Additionally in some case an unique view on e-government service quality is quite useful. A mathematical model provides a single value for quality starting from the assessment of all the requirements defined in the quality model. It relies on the following activities: homogeneity, interaction and grouping.\ud A set of experiments has been performed in order to validate the goodness of the work. Services already implemented in a local Public Administration has\ud been considered. Literature review and domain experts knowledge were the main drivers of this work. It proofs the goodness of the quality model, the application of formal techniques in the complex field of study such as e-government and the quality aggregation via the mathematical model.\ud This thesis introduces advance research in e-government by providing the contributions that quality oriented service delivery in Public Administration promotes services used by the citizens. Further applications of the proposed approaches could be investigated in the areas of practical benchmarking and Service Level Agreement specification

at the 14th Conference of the Spanish Association for Artificial Intelligence (CAEPIA 2011)

Technical Report TR-2011/1, Department of Languages and Computation. University of Almeria November 2011. Joaquín Cañadas, Grzegorz J. Nalepa, Joachim Baumeister (Editors)The seventh workshop on Knowledge Engineering and Software Engineering (KESE7) was held at the Conference of the Spanish Association for Artificial Intelligence (CAEPIA-2011) in La Laguna (Tenerife), Spain, and brought together researchers and practitioners from both fields of software engineering and artificial intelligence. The intention was to give ample space for exchanging latest research results as well as knowledge about practical experience.University of Almería, Almería, Spain. AGH University of Science and Technology, Kraków, Poland. University of Würzburg, Würzburg, Germany

Web service composition: A survey of techniques and tools

Web services are a consolidated reality of the modern Web with tremendous, increasing impact on everyday computing tasks. They turned the Web into the largest, most accepted, and most vivid distributed computing platform ever. Yet, the use and integration of Web services into composite services or applications, which is a highly sensible and conceptually non-trivial task, is still not unleashing its full magnitude of power. A consolidated analysis framework that advances the fundamental understanding of Web service composition building blocks in terms of concepts, models, languages, productivity support techniques, and tools is required. This framework is necessary to enable effective exploration, understanding, assessing, comparing, and selecting service composition models, languages, techniques, platforms, and tools. This article establishes such a framework and reviews the state of the art in service composition from an unprecedented, holistic perspective

Formal verification of enterprise integration architectures

This is a near-finished paper to be presented in an international research conference. Weak Bisimulation is a process calculus equivalence relation, applied for the verification of communicating concurrent systems [Miln 99]. In this paper we propose the application of Weak Bisimulation for Enterprise Application Integration verification. Formal verification is carried out by taking the system specification and design models of an integrated system and converting them into value passing CCS (Calculus of Communicating Systems) processes. If a Weak Bisimulation relation is found between the two models, then it could be concluded that the EI Architecture is a valid one. The formal verification of an EI Architecture would give value to an EI project framework, allowing the challenge of cumbersome and complex testing typically faced by EI projects [Khan 05], to be alleviated, and thus increasing the possibility of a successful EI project, delivered on time and within the stipulated budgeted costs. This paper shows the applicability of value passing CCS (or equivalent) formal notation to model the EI systems characteristics, as well as investigates into the computation complexity of available weak bisimulation algorithms, in order to analyze the applicability of this proposition in real life.peer-reviewe

Supporting Quality of Service in Scientific Workflows

While workflow management systems have been utilized in enterprises to support businesses for almost two decades, the use of workflows in scientific environments was fairly uncommon until recently. Nowadays, scientists use workflow systems to conduct scientific experiments, simulations, and distributed computations. However, most scientific workflow management systems have not been built using existing workflow technology; rather they have been designed and developed from scratch. Due to the lack of generality of early scientific workflow systems, many domain-specific workflow systems have been developed. Generally speaking, those domain-specific approaches lack common acceptance and tool support and offer lower robustness compared to business workflow systems. In this thesis, the use of the industry standard BPEL, a workflow language for modeling business processes, is proposed for the modeling and the execution of scientific workflows. Due to the widespread use of BPEL in enterprises, a number of stable and mature software products exist. The language is expressive (Turingcomplete) and not restricted to specific applications. BPEL is well suited for the modeling of scientific workflows, but existing implementations of the standard lack important features that are necessary for the execution of scientific workflows. This work presents components that extend an existing implementation of the BPEL standard and eliminate the identified weaknesses. The components thus provide the technical basis for use of BPEL in academia. The particular focus is on so-called non-functional (Quality of Service) requirements. These requirements include scalability, reliability (fault tolerance), data security, and cost (of executing a workflow). From a technical perspective, the workflow system must be able to interface with the middleware systems that are commonly used by the scientific workflow community to allow access to heterogeneous, distributed resources (especially Grid and Cloud resources). The major components cover exactly these requirements: Cloud Resource Provisioner Scalability of the workflow system is achieved by automatically adding additional (Cloud) resources to the workflow system’s resource pool when the workflow system is heavily loaded. Fault Tolerance Module High reliability is achieved via continuous monitoring of workflow execution and corrective interventions, such as re-execution of a failed workflow step or replacement of the faulty resource. Cost Aware Data Flow Aware Scheduler The majority of scientific workflow systems only take the performance and utilization of resources for the execution of workflow steps into account when making scheduling decisions. The presented workflow system goes beyond that. By defining preference values for the weighting of costs and the anticipated workflow execution time, workflow users may influence the resource selection process. The developed multiobjective scheduling algorithm respects the defined weighting and makes both efficient and advantageous decisions using a heuristic approach. Security Extensions Because it supports various encryption, signature and authentication mechanisms (e.g., Grid Security Infrastructure), the workflow system guarantees data security in the transfer of workflow data. Furthermore, this work identifies the need to equip workflow developers with workflow modeling tools that can be used intuitively. This dissertation presents two modeling tools that support users with different needs. The first tool, DAVO (domain-adaptable, Visual BPEL Orchestrator), operates at a low level of abstraction and allows users with knowledge of BPEL to use the full extent of the language. DAVO is a software that offers extensibility and customizability for different application domains. These features are used in the implementation of the second tool, SimpleBPEL Composer. SimpleBPEL is aimed at users with little or no background in computer science and allows for quick and intuitive development of BPEL workflows based on predefined components