Die vorliegende Dissertation präsentiert eine umfassende Analyse und Strukturierung des Marktes für netzbasierte Dienste. Basierend auf einer detaillierten Untersuchung des ASP-Angebotes und der ASP-Nachfrage in Europa werden geeignete Institutionen und Informationssubstitute für die Anpassung (Matching) des ASP-Angebotes und der ASP-Nachfrage identifiziert und getestet. Die Strukturierung der Angebotsseite umfasst neben der Bewertung der Marktlage die Entwicklung der ASP-Wertschöpfungskette, die Einordnung in die Systematik der digitalen Güter, die Beschreibung der ASP-Technologien und -Geschäftsmodelle und den Vergleich des ASP-Geschäftsmodells mit der klassischen Softwarenutzung und dem Konzept der virtuellen Organisationen. Die Ergebnisse der Untersuchungen zeigen vorhandene Defizite in der Informations- und Kommunikationspolitik der ASP-Angebotsseite auf. Für die Strukturierung der Nachfrageseite für netzbasierte Dienste werden die Theorien der Auslagerung (Outsourcing) von Informationstechnologien, die Methoden und Instrumente der Kosten- und Nutzenmessung und die Theorie der Transaktionsphasen der Auslagerung angewendet. Kern der wissenschaftlichen Untersuchung bildet die empirische Untersuchung des ASP-Nachfragemarktes in Deutschland und anderen europäischen Ländern. Die Erkenntnisse der Analyse des ASP-Angebotes und der ASP-Nachfrage werden gegenübergestellt und Methoden zur Abstimmung von ASP-Angebot und Nachfrage mit Hilfe der Transaktionskostentheorie und den Theorien der Informations- und Institutionenökonomie abgeleitet. Barrieren, Intransparenzen und Informationsasymmetrien werden auf beiden Seiten aufgezeigt und darauf aufbauend Informationssubstitute für netzbasierte Dienste identifiziert. Erfahrungs- und Vertrauenseigenschaften werden mit Hilfe von Informationssubstituten in einem Onlinebefragungsexperiment hinsichtlich der Wahrnehmung, Wirkung und möglicher Zahlungsbereitschaften überprüft. Aus den Ergebnissen des Onlinebefragungsexperimentes werden Anforderungen an die Informations- und Kommunikationspolitik und Strategien zur Reduzierung der Informationsasymmetrie für netzbasierte Dienste entwickelt. Das Ergebnis der Arbeit ist die Ableitung relevanter Kriterien für die Darstellung und Bewertung der Leistungsbündel netzbasierter Dienste und die Entwicklung von Strategien zur Reduzierung der Transaktionsunsicherheit durch die Identifizierung und Integration von Informationssubstituten für netzbasierte Dienste. / This dissertation presents a comprehensive analysis and conceptual framework of the web-based Application Service Provider (ASP) market. Based on a detailed analysis of ASP supply and demand in Europe, appropriate institutions and information substitutes for the matching process on the ASP market are identified and evaluated. The conceptual framework for the supply side is developed by evaluating the market situation, designing an ASP value chain, classifying digital goods, describing the ASP technologies and business models. These are then compared with the classic model of software utilization and the concept of virtual organizations. The results indicate present deficits in the supply-side information and communication policy. For ASP demand, theories of outsourcing of information technologies, methods and instruments of cost-and-utility-measuring and the theory of transaction phases of outsourcing are used. The basis for both supply-side and demand-side evaluations is an empirical analysis of the European ASP market. We compare the outcome of the supply and demand analyses and derive methods for their coordination by the transaction cost theory and the theories of information and institution economy. Barriers, lack of transparencies and information asymmetries are identified on both sides and thus, information substitutes for web-based services are developed. Information substitutes for experience and trust characteristics are evaluated with an online-questionnaire completed by key participants based on their perception, action and willingness to pay. From those results, we deduce strategies for reducing the information asymmetry. The result of the work is the deduction of relevant criteria for the presentation and evaluation for the supply of web-based services and the development of strategies for reducing the transaction uncertainty by identifying and integrating information substitutes.

Coreografias de serviços Web representam uma forma mais escalável e flexível de compor serviços do que uma abordagem centralizada como a orquestração, e seu papel na integração e comunicação de sistemas de larga escala é vital para os objetivos da SOC (Computação Orientada a Serviços) e da Internet do Futuro. Atualmente coreografias de serviços Web possuem vários desafios de pesquisa, dos quais a qualidade de serviço (QoS) e o monitoramento de coreografias de serviçosWeb são linhas importantes. O objetivo deste trabalho é propor e implementar um mecanismo de monitoramento não intrusivo de coreografias de serviços Web baseado em SLAs (Acordos de Nível de Serviço) que especificam as restrições de atributos de QoS de maneira probabilística. Esta dissertação propõe um mecanismo para coreografias de serviços Web que: (1) define requisitos de QoS; (2) especifica contratos probabilísticos sobre parâmetros de QoS usando SLA; e (3) realiza um monitoramento não intrusivo de coreografias de serviços Web para detectar violações de SLA. / Web services choreographies are a more scalable and flexible way to compose services than a centralized approach like orchestrations, and its role in the integration and communication of large-scale systems is vital for the goals of SoC (Service Oriented Computing) and Future Internet. Currently,Web services choreographies have several research challenges. From all challenges, quality of service (QoS) and monitoring of Web services choreography are important research lines. The goal of this work is to propose and implement a mechanism for non-intrusive monitoring of Web services choreography based on SLAs (Service Level Agreements) that define constraints of QoS attributes in a probabilistic way. This thesis proposes a mechanism for Web services choreographies that:(1) defines QoS requirements; (2) specifies probabilistic contracts on QoS parameters using SLAs; and (3) monitors, non-intrusively, the enactment of Web services choreographies to detect SLA violations.

Les services Web (SW) sont considérés comme étant un bloc pilier pour la réalisation de transactions électroniques entre entreprises. Ainsi, de plus en plus d'entreprises utilisent des SW pour réaliser des transactions avec leurs partenaires et/ou offrir des services en ligne. Dans un tel contexte, chaque entreprise possède un ou plusieurs référentiels privés de descriptions de SW. Pour que ses SW soient consultables et puissent être découverts par d'autres entreprises, une entreprise devra rendre ses référentiels de SW publics. La solution couramment utilisée consiste à publier les descriptions de ses SW dans des annuaires de SW. En conséquence, le nombre d'annuaires disponibles peut être aussi important que le grand nombre d'entreprises et la découverte d'un SW devient ainsi une tâche fastidieuse pour un demandeur de services et coûteuse pour un système de découverte. L'objectif principal de cette thèse est de fournir des solutions pour assurer une découverte d'annuaires de SW adaptée à un environnement distribué. Pour ce faire, nous proposons tout d'abord d'organiser le réseau d'annuaires en communautés. Ensuite, afin de préserver la consistance de cette organisation face aux changements qui peuvent se produire (départ/arrivée d'annuaires), nous définissons les mécanismes de gestion nécessaires. Enfin, nous proposons une approche pour la découverte d'annuaires de SW qui utilise deux filtres pour limiter l'espace de recherche d'un demandeur de services. Les solutions proposées ont été testées par la mise en place d'un réseau de communautés d'annuaires, l'implémentation d'un gestionnaire de communautés et d'un système de découverte d'annuaires. / Web services (WS) can be seen as a pillar block for achieving electronic B2B transactions. More and more companies are using WS to achieve transactions with their partners and/or offer on-line services. These companies have to make their WS available for consultation through their own private WS registries. As a result, the number of WS registries that are made available for use can be as many as the large number of companies. This raises an old, search engine, problem in a new form: discovery mechanisms of WS are not efficient both in response times and quality of results. In this context, if appropriate solutions are not considered, "traditional" WS discovery mechanisms that consist of scanning all the registries would for instance slow down the increase rate of WS. In this thesis, we are interested in WS discovery in a distributed registry environment. To do this, we first propose to organize a registries network into communities based on functionalities offered by the WS of a registry. Then, to handle the dynamic nature of communities and their members, we define the needed management mechanisms to monitor changes and reconcile potential conflicts. Finally, we propose an approach for WS registries discovery that uses two filters to limit the search space. We first use the functional requirement of a service requester to select the appropriate registry community. Then we use the requester's non-functional requirements and his behavior to select the registries. The proposed solutions were tested by setting up a P2P network of registry communities, implementing a community manager and a discovery system.

No description available.

Coreografias de serviços Web representam uma forma mais escalável e flexível de compor serviços do que uma abordagem centralizada como a orquestração, e seu papel na integração e comunicação de sistemas de larga escala é vital para os objetivos da SOC (Computação Orientada a Serviços) e da Internet do Futuro. Atualmente coreografias de serviços Web possuem vários desafios de pesquisa, dos quais a qualidade de serviço (QoS) e o monitoramento de coreografias de serviçosWeb são linhas importantes. O objetivo deste trabalho é propor e implementar um mecanismo de monitoramento não intrusivo de coreografias de serviços Web baseado em SLAs (Acordos de Nível de Serviço) que especificam as restrições de atributos de QoS de maneira probabilística. Esta dissertação propõe um mecanismo para coreografias de serviços Web que: (1) define requisitos de QoS; (2) especifica contratos probabilísticos sobre parâmetros de QoS usando SLA; e (3) realiza um monitoramento não intrusivo de coreografias de serviços Web para detectar violações de SLA. / Web services choreographies are a more scalable and flexible way to compose services than a centralized approach like orchestrations, and its role in the integration and communication of large-scale systems is vital for the goals of SoC (Service Oriented Computing) and Future Internet. Currently,Web services choreographies have several research challenges. From all challenges, quality of service (QoS) and monitoring of Web services choreography are important research lines. The goal of this work is to propose and implement a mechanism for non-intrusive monitoring of Web services choreography based on SLAs (Service Level Agreements) that define constraints of QoS attributes in a probabilistic way. This thesis proposes a mechanism for Web services choreographies that:(1) defines QoS requirements; (2) specifies probabilistic contracts on QoS parameters using SLAs; and (3) monitors, non-intrusively, the enactment of Web services choreographies to detect SLA violations.

Dans une composition de services Web basée protocole, un ensemble de services composants se collaborent pour donner lieu à un service Composite. Chaque service est représenté par un automate à états finis (AEF). Au sein d’un AEF, chaque transition exprime l’exécution d’une opération qui fait avancer le service vers un état suivant. Une exécution du composite correspond à une séquence de transitions où chacune est déléguée à un des composants. Lors de l’exécution du composite, un ou plusieurs composants peuvent devenir indisponibles. Ceci peut produire une exécution incomplète du composite, et de ce fait un recouvrement est nécessaire. Le recouvrement consiste à transformer l’exécution incomplète en une exécution alternative ayant encore la capacité d’aller vers un état final. La transformation s'effectue en compensant certaines transitions et exécutant d’autres. Cette thèse présente une étude formelle du problème de recouvrement dans une composition de service Web basée protocole. Le problème de recouvrement consiste à trouver une meilleure exécution alternative parmi celles disponibles. Une meilleure alternative doit être atteignable à partir de l’exécution incomplète avec un nombre minimal de compensations visibles (vis-à-vis le client). Pour une exécution alternative donnée, nous prouvons que le problème de décision associé au calcul du nombre de transitions invisiblement compensées est NP-Complet. De ce fait, nous concluons que le problème de décision associé au recouvrement appartient à la classe ΣP2. / In a protocol-based Web service composition, a set of available component services collaborate together in order to provide a new composite service. Services export their protocols as finite state machines (FSMs). A transition in the FSM represents a task execution that makes the service moving to a next state. An execution of the composite corresponds to a sequence of transitions where each task is delegated to a component service. During composite run, one or more delegated components may become unavailable due to hard or soft problems on the Network. This unavailability may result in a failed execution of the composite. We provide in this thesis a formal study of the automatic recovery problem in the protocol-based Web service composition. Recovery consists in transforming the failed execution into a recovery execution. Such a transformation is performed by compensating some transitions and executing some others. The recovery execution is an alternative execution of the composite that still has the ability to reach a final state. The recovery problem consists then in finding the best recovery execution(s) among those available. The best recovery execution is attainable from the failed execution with a minimal number of visible compensations with respect to the client. For a given recovery execution, we prove that the decision problem associated with computing the number of invisibly-compensated transitions is NP-complete. Thus, we conclude that deciding of the best recovery execution is in ΣP2.

Online Communities verzeichnen seit einiger Zeit ein rasantes Wachstum. Diese Entwicklung führt zunehmend dazu, dass die Portale für bestimmte Personengruppen wichtige Funktionalitäten nicht zu Verfügung stellen können oder die Nutzer durch eine Vielzahl für sie unnötiger Funktionen überfordert werden. Als Ergebnis dieser Erfahrungen zwischen Datenflut und Überforderung durch die ansteigende Komplexität der Bedienung auf der einen Seite und Informationsmangel und fehlender Funktionalität auf der anderen Seite, begründen Gemeinschaften spezialisierte Online-Communities. Der vorliegende Artikel liefert dazu einen State-of-the-Art Überblick kostenfreier Online-Services zur Erstellung sozialer Netwerke und vergleicht sie in Hinblick auf Kollaboration und Kommunikation, Datenschutz, Kontaktmanagement, Anpassbarkeit und Administrierbarkeit.

Visualisering är en ofta förekommande metod som används vid utveckling av en ny produkt för att redan i ett tidigt stadium kunna visa den färdiga produkten i form av en prototyp eller annan digital ritning. Det är dock inte lika vanligt att visualisera själva utvecklingen av produkten eller vilken fas den befinner sig i, vilket kan leda till osäkerhet inom utvecklingsgruppen och ge det fortsatta arbetet av produkten en tvetydig bild. Projektgrupperna på företaget CGI Östersund jobbar enligt den agila systemutvecklingsmetoden Scrum där arbetet delas upp i olika delleveranser och ärenden, vilket gör det möjligt att visualisera utvecklingsprocessen. Den här undersökningen har studerat Scrum-metoden ytterligare och därefter tagit fram ett visualiseringsverktyg bestående av en REST-webbtjänst i Java och en webbklient som hämtar information från ett ärendehanteringssystem, JIRA, som företaget använder sig av. Informationen presenteras sedan i form av olika grafer beroende på vad som skall visualiseras. Verktygets funktion och konstruktion har sedan utvärderats med användbarhetstester och även jämförts med ett liknande verktyg som redan finns i den befintliga JIRA-plattformen. Användbarhetstesterna utfördes både innan och efter implementation där det första testet enbart bestod av mock-ups och det andra när verktyget hade fått ett fungerande resultat. Resultatet har visat att det fortfarande råder en del oklarhet i verktygets mer invecklade funktioner, men att helheten av de olika delsystemen är förståelig i dess användbarhet. Jämförelsen med visualiseringen i JIRA visar att liknelserna är stora och att det i nuläget finns både för- och nackdelar med att använda den här lösningen. Verktyget är i övrigt uppbyggd med moderna tekniker och står på en bra grund för vidare utveckling från företagets sida. / Visualization is a frequent method used in the development of a new product to see the finished product to an early stage in the form of a prototype or digital drawing. However, it is not as common to visualize the actual development of the product or what phase it is in, which can lead to confusion within the development team and provide further the work of the product an ambiguous picture. Project teams at the company CGI Östersund works according to the agile system development methodology Scrum where the work is divided into different partial deliveries and issues, making it possible to visualize the development process. This investigation has studied the Scrum method further and then developed a visualization tool consisting of a REST web service in Java and a web client that retrieves information from a issue tracking system, JIRA, which the company uses. The information is then presented in the form of various graphs depending on what is to be visualized. The tool's function and design has been evaluated with usability testing and also then compared with a similar tool that is already in the existing JIRA platform. Usability tests were conducted both before and after implementation, the first test consisted only of mock-ups and the second when the tool had a functioning results. The results have shown that there is still some ambiguity in the tool's more complex features, but to the whole of the various subsystems is understandable in its usability. The comparison with the visualization in JIRA shows that the parables are great and that at present there are both advantages and disadvantages of using this solution. The tool is otherwise constructed with modern techniques and stands on a good basis for further development from the company.

<p>This thesis consists of a strategy to integrate distributed systems with the aid of web services. The focus of this research involves three subjects, web services and distributed database systems and its application on a real-life project.</p><p>For defining the context in this thesis, we present the research methodology that provides the path where the investigation will be performed and the general concepts of the running environment and architecture of web services.</p><p>The mayor contribution for this thesis is a solution for the Chamber Trade in Sweden and VNemart in Vietnam obtaining the requirement specification according to the SPIDER project needs and our software design specification using distributed databases and web services.</p><p>As results, we present the software implementation and the way or software meets and the requirements previously defined. For future web services developments, this document provides guidance for best practices in this subject.</p>

運用語義網本體論來描述網路服務，實現網路服務的自動發現、調用和組合已經被證實是有效的。人工智慧規劃技術就是運用此技術描述網路服務來達到自動化網路服務組合。OWL-S支援使用OWL來描述網路服務的前提與效果，而在OWL的規則描述語言方面，則可以使用SWRL。本論文是以OntoComposer規劃工具為基礎，發展一套前置處理器來簡化其使用，讓使用者不需具備人工智慧規劃描述語言及語義網路服務描述等知識，只要尋找到符合需求之網路服務後，就可以自動轉換成支持條件分支圖規劃器之輸入文件，並在設定目標後進行規劃組合，最後讓組合之複合網路能夠在執行引擎上正確執行。 / Using Semantic Web ontologies to describe Web Services has proven to be effective for automatic service discovery, invokcation and composition. AI planning techniques have been employed to automate the composition of Web Services in this way. OWL-S supports the description of the preconditions and effects of a web service using OWL statements, and SWRL is the language for expressing OWL Rules. OntoComposer is an AI planning based tool for Combining-GraphPlan, an extension for GraphPlan so that supports condition branching. This thesis presents a preprocessor for OntoComposer to simplify its input task so that the user does not have to learn the AI Planning description language and knowledge of the semantic web service description. Just look to meet the demand of web services, our preprocessor will translate them to support branch planning for the input file. After setting the targets the OntoComposer will compose some component web services to a complex web service. Finally, let the composition of web services on the execution engine the correct execution.