Cohesion-Driven Decomposition of Service Interfaces without Access to Source Code

International audience—Software cohesion concerns the degree to which the elements of a module belong together. Cohesive software is easier to understand, test and maintain. In the context of service-oriented development, cohesion refers to the degree to which the operations of a service interface belong together. In the state of the art, software cohesion is improved based on refactoring methods that rely on information, extracted from the software implementation. This is a main limitation towards using these methods in the case of Web services: Web services do not expose their implementation; instead all that they export is the Web service interface specification. To deal with this problem, we propose an approach that enables the cohesion-driven decomposition of service interfaces, without information on how the services are implemented. Our approach progressive decomposes a given service interface into more cohesive interfaces; the backbone of the approach is a suite of cohesion metrics that rely on information, extracted solely from the specification of the service interface. We validate the approach in 22 real-world services, provided by Amazon and Yahoo. We assess the effectiveness of the proposed approach, concerning the cohesion improvement, and the number of interfaces that result from the decomposition of the examined interfaces. Moreover, we show the usefulness of the approach in a user study, where developers assessed the quality of the produced interfaces

Cohesion-Driven Decomposition of Service Interfaces Without Access to Source Code

Software cohesion concerns the degree to which the elements of a module belong together. Cohesive software is easier to understand, test and maintain. Improving cohesion is the target of several refactoring methods that have been proposed until now. These methods are tailored to operate by taking the source code into consideration. In the context of service-oriented development, cohesion refers to the degree to which the operations of a service interface belong together. In this context, we propose an approach for the cohesion-driven decomposition of service interfaces. The very philosophy of services dictates that all that is exported by a service is the service specification. Hence, our approach for the cohesion-driven decomposition of service interfaces is not based on how the services are implemented. Instead, it relies only on information provided in the specification of the service interfaces. We validate the approach in 22 real-world services provided by Amazon and Yahoo. We show the effectiveness of the proposed approach, concerning the cohesion improvement and the size of the produced decompositions. Moreover, we show that the proposed approach is useful, by conducting a user study, where developers assessed the quality of the produced decompositions

Design Principles for B2B Services – An Evaluation of Two Alternative Service Designs

A service-oriented architecture (SOA) promises a more flexible intra- and interorganizational integration of heterogeneous application systems. The central design element of a SOA consists of services which encapsulate existing application logic, and can be dynamically combined to form business processes. This paper aims at contributing to the emerging discipline of “service engineering ” by investigating the design principles for B2B services. The authors draw on an analysis of the literature to derive the main design principles for services and evaluate two alternative design proposals for a concrete application scenario in the automotive industry. The results comprise on the one hand statements on the quality of the service design in the concrete case and on the other the outlook for future topics of research in “service engineering”. 1

Incorporating an Element of Negotiation into a Service-Oriented Broker Application

The Software as a Service (SaaS) model is a service-based model in which a desired service is assembled, delivered and consumed on demand. The IBHIS broker is a ‘proof of concept’ demonstration of SaaS which is based on services that deliver data. IBHIS has addressed a number of challenges for several aspects of servicebased software, especially the concept of a ‘broker service’ and service negotiation that is only used in establishing end-user access authorizations. This thesis investigates and develops an extended form of service-based broker, called CAPTAIN (Care Planning Through Auction-based Information Negotiation). It extends the concepts and role of the broker as used in IBHIS, and in particular, it extends the service negotiation function in order to demonstrate a full range of service characteristics. CAPTAIN uses the idea of the integrated care plan from healthcare to provide a case study. A care planner acting on behalf of a patient uses the broker to negotiate with providers to produce the integrated care plan for the patient with the broker and the providers agreeing on the terms and conditions relating to the supply of the services. We have developed a ‘proof of concept’ service-oriented broker architecture for CAPTAIN that includes planning, negotiation and service-based software models to provide a flexible care planning system. The CAPTAIN application has been evaluated that focuses on three features: functions, data access and negotiation. The CAPTAIN broker performs as planned, to produce the integrated care plan. The providers’ data sources are accessed to read and write data records during and after service negotiation. The negotiation model permits the broker to interact with the providers to produce an adaptable plan, based on the client’s needs. The primary outcome is an extendable service-oriented broker architecture that can enable more scalable and flexible distributed information management by adding interaction with the data sources

Rahmenwerk zur integrativen Gestaltung von Services: Modellgetriebene Servicebeschreibung

Die vorliegende Arbeit befasst sich mit der modellgetriebenen Servicebeschreibung, einem Ansatz zur integrativen Beschreibung bzw. Modellierung von Services. Ausgehend von der Prämisse, dass die Natur von Services nur schwer zu erfassen ist und eine Disziplinen-übergreifende Positiv-Definition nicht erreicht werden kann, soll mit dem Ansatz eine Syn-these bisher vorhandener Modellierungsansätze erfolgen. Das Ziel liegt dabei nicht in einem erneuten Versuch, ein vollständiges Modell zur Beschreibung von Services zu entwickeln, sondern vielmehr vorhandene Perspektiven so zu integrieren, dass ein vollständiges Bild als eine Art Mosaik entsteht. Den Kern der Arbeit bildet das Service Modeling Framework. Als Rahmenwerk umfasst es Anforderungen und Restriktionen für die Arbeit mit unter-schiedlichen Servicemodellen, definiert Methoden zur Integration und bietet Werkzeuge, mit deren Hilfe die darin enthaltenen Konzepte umgesetzt werden. Ziel der Konstruktion des Rahmenwerks ist es Nutzer in die Lage zu versetzen mittels mo-dellgetriebener Verfahren eine Zusammenführung von Modellen zu ermöglichen. Auf Basis einer fachlichen, nicht nur syntaktischen Beschreibung von Beziehungen zwischen Model-len und Modellelementen sollen Zusammenhänge modelliert werden, die einen Informati-onsaustausch zwischen Modellen realisieren. Dadurch werden Abhängigkeiten zwischen Modellen explizit formuliert oder aber die Entwicklung neuer Modelle auf Basis bereits bestehender Modelle vorangetrieben. Der Beitrag dieser Arbeit besteht in der Erarbeitung der notwendigen Konzepte und in der Bereitstellung geeigneter Verfahren sowie Werkzeugen zur Umsetzung. Insbesondere stellt diese Arbeit einen Metamodell-basierten Ansatz zur Verfügung, mit dem Modelle über ein Domänen-neutrales Basismetamodell zueinander in Beziehung gesetzt werden können. Zugehörige Werkzeuge, wie Editoren, zeigen eine prototypische Umsetzbarkeit

A Reference Architecture for Service Lifecycle Management – Construction and Application to Designing and Analyzing IT Support

Service-orientation and the underlying concept of service-oriented architectures are a means to successfully address the need for flexibility and interoperability of software applications, which in turn leads to improved IT support of business processes. With a growing level of diffusion, sophistication and maturity, the number of services and interdependencies is gradually rising. This increasingly requires companies to implement a systematic management of services along their entire lifecycle. Service lifecycle management (SLM), i.e., the management of services from the initiating idea to their disposal, is becoming a crucial success factor. Not surprisingly, the academic and practice communities increasingly postulate comprehensive IT support for SLM to counteract the inherent complexity. The topic is still in its infancy, with no comprehensive models available that help evaluating and designing IT support in SLM. This thesis presents a reference architecture for SLM and applies it to the evaluation and designing of SLM IT support in companies. The artifact, which largely resulted from consortium research efforts, draws from an extensive analysis of existing SLM applications, case studies, focus group discussions, bilateral interviews and existing literature. Formal procedure models and a configuration terminology allow adapting and applying the reference architecture to a company’s individual setting. Corresponding usage examples prove its applicability and demonstrate the arising benefits within various SLM IT support design and evaluation tasks. A statistical analysis of the knowledge embodied within the reference data leads to novel, highly significant findings. For example, contemporary standard applications do not yet emphasize the lifecycle concept but rather tend to focus on small parts of the lifecycle, especially on service operation. This forces user companies either into a best-of-breed or a custom-development strategy if they are to implement integrated IT support for their SLM activities. SLM software vendors and internal software development units need to undergo a paradigm shift in order to better reflect the numerous interdependencies and increasing intertwining within services’ lifecycles. The SLM architecture is a first step towards achieving this goal.:Content Overview List of Figures....................................................................................... xi List of Tables ...................................................................................... xiv List of Abbreviations.......................................................................xviii 1 Introduction .................................................................................... 1 2 Foundations ................................................................................... 13 3 Architecture Structure and Strategy Layer .............................. 57 4 Process Layer ................................................................................ 75 5 Information Systems Layer ....................................................... 103 6 Architecture Application and Extension ................................. 137 7 Results, Evaluation and Outlook .............................................. 195 Appendix ..........................................................................................203 References .......................................................................................... 463 Curriculum Vitae.............................................................................. 498 Bibliographic Data............................................................................ 49