118 research outputs found

    Flexible modeling and execution of choreographies

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    Approaches to address domain specific problems often share overlapping requirements but typically satisfy them in a unique manner for example using service-oriented concepts. The notion of Collaborative, Dynamic & Complex (CDC) systems has been proposed in literature to address the requirements of application domains such as eScience and Collective Adaptive Systems in a unified, generic manner. CDC systems are characterized by dealing with potentially large amounts of data and/or participating applications which engage in complex interactions specified by some collaboration protocol. Furthermore, the need for adaptation mechanisms is a common requirement and users from these application domains are typically no IT experts. The choreography concept originally known from collaborations in the business domain captures the interaction between independent parties from a global perspective. Each party is denoted as a choreography participant, which is implemented by a workflow or a service. This concept provides a way to model and execute for example complex eScience experiments involving multiple scientific fields, scientific methods, and time and/or length scales as a set of coupled workflows. However, typical choreography concepts as described in literature do not provide the desired level of flexibility and ease of use in both modeling and execution to address the requirements of users in CDC system application domains such as eScience. Thus, existing choreography concepts have to be considerably extended by introducing the Model-as-you-go for Choreographies approach in this thesis as a central notion providing capabilities for the flexible modeling and execution of choreographies. In the context of this approach, we provide a concept for fostering reuse in choreography modeling in the form of so-called choreography fragments. Such fragments can be extracted from existing and inserted into new choreography models in order to save time as well as reuse established and approved logic by inexperienced modelers in a less error-prone manner. Furthermore, we provide support for the user-driven control of the complete choreography life cycle. This effectively allows users to automatically deploy the workflow models implementing a choreography as well as starting, pausing, resuming, and terminating a choreography instance, which is formed through the collective execution of workflow instances. Most importantly, the underlying complexity of managing a set of coupled workflow instances is completely hidden from the users. Additional flexibility is given by a concept that allows to re-run already executed choreography logic in order to enforce the convergence of a calculation towards a particular result or to react to errors with parameter changes. The proposed concepts are implemented in a message-based system, the ChorSystem, which is able to handle the challenges of choreography life cycle management from deployment, to run time control and the re-run of logic. Furthermore, the modeling and run time monitoring are integrated into one graphical tool supporting the seamless transition from modeling to execution of choreographies. The concepts, their supporting algorithms, and the prototypical ChorSystem are validated by a set of case studies from different CDC system application domains and evaluated by performance measurements showing the practical applicability

    Survey on Choreography for Web Services

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    Web service choreography is used to interchange the message between source and destination. The transfer message is based on the data type and transmission sequence. For many years, organizations have been developing solutions for automating their peer-to-peer collaborations, within or across their trusted domain, in an effort to improve productivity and reduce operating costs. Web Services are a key component of the emerging, loosely coupled, Web-based computing architecture. A Web Service is an autonomous, standards-based component whose public interfaces is defined and described using XML. Other systems may interact with a Web Service in a manner prescribed by its definition, using XML based messages conveyed by Internet protocols

    A software architecture for electro-mobility services: a milestone for sustainable remote vehicle capabilities

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    To face the tough competition, changing markets and technologies in automotive industry, automakers have to be highly innovative. In the previous decades, innovations were electronics and IT-driven, which increased exponentially the complexity of vehicle’s internal network. Furthermore, the growing expectations and preferences of customers oblige these manufacturers to adapt their business models and to also propose mobility-based services. One other hand, there is also an increasing pressure from regulators to significantly reduce the environmental footprint in transportation and mobility, down to zero in the foreseeable future. This dissertation investigates an architecture for communication and data exchange within a complex and heterogeneous ecosystem. This communication takes place between various third-party entities on one side, and between these entities and the infrastructure on the other. The proposed solution reduces considerably the complexity of vehicle communication and within the parties involved in the ODX life cycle. In such an heterogeneous environment, a particular attention is paid to the protection of confidential and private data. Confidential data here refers to the OEM’s know-how which is enclosed in vehicle projects. The data delivered by a car during a vehicle communication session might contain private data from customers. Our solution ensures that every entity of this ecosystem has access only to data it has the right to. We designed our solution to be non-technological-coupling so that it can be implemented in any platform to benefit from the best environment suited for each task. We also proposed a data model for vehicle projects, which improves query time during a vehicle diagnostic session. The scalability and the backwards compatibility were also taken into account during the design phase of our solution. We proposed the necessary algorithms and the workflow to perform an efficient vehicle diagnostic with considerably lower latency and substantially better complexity time and space than current solutions. To prove the practicality of our design, we presented a prototypical implementation of our design. Then, we analyzed the results of a series of tests we performed on several vehicle models and projects. We also evaluated the prototype against quality attributes in software engineering

    Business rules based legacy system evolution towards service-oriented architecture.

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    Enterprises can be empowered to live up to the potential of becoming dynamic, agile and real-time. Service orientation is emerging from the amalgamation of a number of key business, technology and cultural developments. Three essential trends in particular are coming together to create a new revolutionary breed of enterprise, the service-oriented enterprise (SOE): (1) the continuous performance management of the enterprise; (2) the emergence of business process management; and (3) advances in the standards-based service-oriented infrastructures. This thesis focuses on this emerging three-layered architecture that builds on a service-oriented architecture framework, with a process layer that brings technology and business together, and a corporate performance layer that continually monitors and improves the performance indicators of global enterprises provides a novel framework for the business context in which to apply the important technical idea of service orientation and moves it from being an interesting tool for engineers to a vehicle for business managers to fundamentally improve their businesses

    SERVICE-BASED AUTOMATION OF SOFTWARE CONSTRUCTION ACTIVITIES

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    The reuse of software units, such as classes, components and services require professional knowledge to be performed. Today a multiplicity of different software unit technologies, supporting tools, and related activities used in reuse processes exist. Each of these relevant reuse elements may also include a high number of variations and may differ in the level and quality of necessary reuse knowledge. In such an environment of increasing variations and, therefore, an increasing need for knowledge, software engineers must obtain such knowledge to be able to perform software unit reuse activities. Today many different reuse activities exist for a software unit. Some typical knowledge intensive activities are: transformation, integration, and deployment. In addition to the problem of the amount of knowledge required for such activities, other difficulties also exist. The global industrial environment makes it challenging to identify sources of, and access to, knowledge. Typically, such sources (e.g., repositories) are made to search and retrieve information about software unitsand not about the required reuse activity knowledge for a special unit. Additionally, the knowledge has to be learned by inexperienced software engineers and, therefore, to be interpreted. This interpretation may lead to variations in the reuse result and can differ from the estimated result of the knowledge creator. This makes it difficult to exchange knowledge between software engineers or global teams. Additionally, the reuse results of reuse activities have to be repeatable and sustainable. In such a scenario, the knowledge about software reuse activities has to be exchanged without the above mentioned problems by an inexperienced software engineer. The literature shows a lack of techniques to store and subsequently distribute relevant reuse activity knowledge among software engineers. The central aim of this thesis is to enable inexperienced software engineers to use knowledge required to perform reuse activities without experiencing the aforementioned problems. The reuse activities: transformation, integration, and deployment, have been selected as the foundation for the research. Based on the construction level of handling a software unit, these activities are called Software Construction Activities (SCAcs) throughout the research. To achieve the aim, specialised software construction activity models have been created and combined with an abstract software unit model. As a result, different SCAc knowledge is described and combined with different software unit artefacts needed by the SCAcs. Additionally, the management (e.g., the execution of an SCAc) will be provided in a service-oriented environment. Because of the focus on reuse activities, an approach which avoids changing the knowledge level of software engineers and the abstraction view on software units and activities, the object of the investigation differs from other approaches which aim to solve the insufficient reuse activity knowledge problem. The research devised novel abstraction models to describe SCAcs as knowledge models related to the relevant information of software units. The models and the focused environment have been created using standard technologies. As a result, these were realised easily in a real world environment. Softwareengineers were able to perform single SCAcs without having previously acquired the necessary knowledge. The risk of failing reuse decreases because single activities can be performed. The analysis of the research results is based on a case study. An example of a reuse environmenthas been created and tested in a case study to prove the operational capability of the approach. The main result of the research is a proven concept enabling inexperienced software engineers to reuse software units by reusing SCAcs. The research shows the reduction in time for reuse and a decrease of learning effort is significant

    ECLAP 2012 Conference on Information Technologies for Performing Arts, Media Access and Entertainment

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    It has been a long history of Information Technology innovations within the Cultural Heritage areas. The Performing arts has also been enforced with a number of new innovations which unveil a range of synergies and possibilities. Most of the technologies and innovations produced for digital libraries, media entertainment and education can be exploited in the field of performing arts, with adaptation and repurposing. Performing arts offer many interesting challenges and opportunities for research and innovations and exploitation of cutting edge research results from interdisciplinary areas. For these reasons, the ECLAP 2012 can be regarded as a continuation of past conferences such as AXMEDIS and WEDELMUSIC (both pressed by IEEE and FUP). ECLAP is an European Commission project to create a social network and media access service for performing arts institutions in Europe, to create the e-library of performing arts, exploiting innovative solutions coming from the ICT

    Monitoring and Information Alignment in Pursuit of an IoT-Enabled Self-Sustainable Interoperability

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    To remain competitive with big corporations, small and medium-sized enterprises (SMEs) often need to be more dynamic, adapt to new business situations, react faster, and thereby survive in today‘s global economy. To do so, SMEs normally seek to create consortiums, thus gaining access to new and more opportunities. However, this strategy may also lead to complications. Due to the different sources of enterprise models and semantics, organizations are experiencing difficulties in seamlessly exchanging vital information via electronic means. In their attempt to address this issue, most seek to achieve interoperability by establishing peer-to-peer mappings with different business partners, or by using neutral data standards to regulate communications in optimized networks. Moreover, systems are more and more dynamic, frequently changing to answer new customer‘s requirements, causing new interoperability problems and a reduction of efficiency. Another situation that is constantly changing is the devices used in the enterprises, as the Enterprise Information Systems, devices are used to register internal data, and to be used to monitor several aspects. These devices are constantly changing, following the evolution and growth of the market. So, it is important to monitor these devices and doing a model representation of them. This dissertation proposes a self-sustainable interoperable framework to monitor existing enterprise information systems and their devices, monitor the device/enterprise network for changes and automatically detecting model changes. With this, network harmonization disruptions are detected in a timely way, and possible solutions are suggested to regain the interoperable status, thus enhancing robustness for reaching sustainability of business networks along time

    Designing and experimenting coordination primitives for service oriented computing

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    Service Oriented Architecture (SOA) and Web Services (WS) are becoming a widely accepted device for designing and implementing distributed systems. SOAs have given an important contribution to software engineering providing a model where applications are defined by assembling together certain functionalities, called services, possibly provided by remote suppliers. The characterizing issue of SOAs consists of defining common principles to make services accessible and usable regardless their execution context. Nevertheless, the architectural specification is far from giving a complete reference application model on which systems should rely on. The specification just includes principles for achieving interoperability and reusability of services; other aspects are left to the implementing platforms. As a consequence, it is understood how services are specified in isolation and how their functionalities are made available to the requesters, but the definition of languages for describing service composition are far from being widely accepted and reveals to be an impelling challenge. In the last years, several solutions have been proposed for describing aggregated services. However, they often lack a formally defined semantics. Moreover, these solutions are often specific for a platform (e.g. WSs) and are difficult to adapt to other platforms since they rely on low level assumptions that are out of the SOA specifications. This thesis aims at providing new methodologies for implementing the coordination of services. Our framework proposes to be flexible enough to support high level languages and to provide reliable tools for testing correctness of implementation. Our approach relies on a formal model that takes the form of a process calculus specifically designed to deal with services and their coordination. The process calculus has been the main tool driving the specification issues as well the implementation issues. Indeed, it acts as a bridge between the high level specification language and the run-time environment. A distinguished feature of our proposal is that our formal model, i.e. the process calculus, describes distributed processes relying on an event notification mechanism as machinery for interactions. Services are represented by certain components that embody local computations and react to changes of the overall environment in which they are involved. The adoption of event notification results particularly fashionable for tackling service coordination. The principles studied at specification level are from one side understood within a theoretical framework that provides instruments for checking correctness of interaction policies and from the other side offers the core model for implementing and experimenting a programming middleware
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