Flexible Loosely Coupled Inter-Organizational Workflows using SOA

8International audienceService Oriented Architecture (SOA) is a paradigm that provides important properties for the development of business applications like flexibility and loose coupling. In our research work, we focus on the use of SOA to implement specific architectures of inter-organizational workflows (IOWF). The current paper deals with the "Loosely Coupled Workflow" specifying an IOWF-architecture that connects two or more workflows -attached to a set of business partners- communicating in an asynchronous manner according to a public communication protocol conjointly defined by all partners. The first issue of this work is to define a service based cooperation pattern called LC-IOWF pattern suitable to the architecture considered in order to obtain IOWF models flexible enough to ease their adaptation. The proposed LC-IOWF pattern is based on three main dimensions: services, control of execution and interactions. Then, we define three categories of adaptation patterns corresponding to the three dimensions exhibited. Particularly, the third category of these patterns called "Interaction adaptation patterns" concerns adaptations affecting the communication protocol and constitutes a specific type of adaptation compared with other IOWF-architectures. For implementation, we consider IOWF models specified with BPEL

Cooperation Patterns and Adaptation Patterns for Service-Based Inter-Organizational Workflows

International audienceModernization is an effective approach to making existing mainframe and distributed systems more responsive to business needs. SOA (service-oriented architecture) is an adequate paradigm that allows companies to tap into the business value in their current systems and position IT for rapid future changes to the business model. In our research works, we focus on the use of SOA to implement Inter- Organizational WorkFlows (IOWF). The goal is to take benefits from the advantages offered by the SOA paradigm like interoperability, reusability and flexibility in order to deal with workflow models easily adaptable, evolvable and reusable. This paper focuses on two specific architectures of IOWF which are the "chained execution" and the "subcontracting"; the first issue of this work is to define Service-Based Cooperation Patterns (SBCP) suitable to the two architectures considered. A SBCP is based on SOA; it is defined through three main dimensions: the distribution of services among the partner's sites, the control of instance execution and the structure of interaction between the workflows involved in the cooperation. The second issue of the paper consists of adaptation and evolution of IOWF process models obeying to the defined SBCP. Then, we state the main operations of adaptation that can be applied on these models; we focus on adaptation at process and interactional levels. Conformably to the three dimensions of SBCP, we define three classes of adaptation patterns: "service adaptation", "control flow adaptation" and "interaction adaptation" patterns. Also, we particularly distinguish some operations of adaptation called evolution of process models based on two perspectives: the expansion of the global functionality of the process and the expansion of the cooperation; we show that some evolutions are realized by reuse of existing IOWF models. For implementation, we consider IOWF process models specified with BPEL

Über die Anwendung des service-orientierten Architekturstils auf heterogene Anwendungslandschaften

This thesis investigates the application of the service-oriented architectural style in the context of industrial enterprises. This style provides a commonly perceived paradigm for organizing distributed software systems. However, beyond general attention to this style, there are only few descriptions of the difference between service orientation and more mature styles, such as component orientation. This dissertation argues that the service-oriented style is an approach that centralizes control over distributed functionality that is provided by the application systems of an organization. This means that service orientation is a paradigm for application integration. Moreover, we argue that it is not possible to fully formalize the inherent principles of service orientation as part of an architectural style description. In fact, soft design principles are a differentiator of this style. These principles, however, are rarely applied in the context of industrial enterprises. This is why we analyze how such design principles could be objectively described and what attention should be paid to them. This analysis is performed by categorizing the potential benefits of this style and assigning the respective underlying principles to the identified benefits. Subsequently, a reference architecture is defined on the basis of these findings. This architecture focuses on structuring service-oriented applications - so-called composite applications. In order to apply the defined reference architecture in the context of actual projects, we describe a design methodology for composite applications. This design methodology focuses on using business processes for designing various types of services and on describing their interconnections by the reference architecture. To achieve this, a service design algorithm is included that derives services from business processes by incorporating the results of a statistical analysis of service design principles. The result of this methodology is a platform-independent design of a composite application. It considers the restrictions of the application landscape in which a composite will be deployed. To permit the realization of composite applications, we informally map the platform-independent reference architecture to a platform that is widely used in industrial enterprises. This mapping is, together with the design methodology and the reference architecture, applied to an industry-scale use case. This way, the applicability of the concepts is demonstrated.Diese Dissertation untersucht, wie der service-orientierte Architekturstil von großen Konzernen angewandt werden kann. Dieser Architekturstil strukturiert verteilte Systeme. Neben allgemeiner Aufmerksamkeit sind jedoch nur wenige Beschreibungen verfügbar, die zeigen, wie sich dieser Stil von anderen - so z.B. von dem der Komponentenorientierung - absetzt. Die vorliegende Arbeit beschreibt, dass der service-orientierte Stil ein Ansatz zur Kontrollzentralisierung ist. Dabei zentralisiert er die Kontrolle über die Funktionalität, die von den Applikationssystemen einer Organisation bereitgestellt wird. Daher kann er auch als Integrationsansatz verstanden werden. Zusätzlich ist es nicht möglich, alle Prinzipien des service-orientierten Stils als Architekturstil zu beschreiben. Tatsächlich stellen weiche Designprinzipien das Alleinstellungsmerkmal dieses Stils dar. Diese Prinzipien werden allerdings von großen Organisationen kaum angewendet. Diese Dissertation untersucht deshalb den Stellenwert der einzelnen Prinzipien und beschreibt, wie sie objektiviert werden können. In dieser Untersuchung werden die möglichen Vorteile dieses Architekturstils zunächst kategorisiert. Danach werden diesen potentiellen Vorteilen die Prinzipien zugewiesen, die zu ihrer Erlangung beitragen. Auf Basis dieser Analyse wird danach eine Referenzarchitektur erstellt. Diese Architektur beschreibt eine Struktur für service-orientierte Applikationen, so genannte composite applications, die es erlaubt weiche Designprinzipien zu berücksichtigen. Um diese Referenzarchitektur auf reelle Problemstellungen anwenden zu können, wird außerdem eine Methodik zum Design von composite applications beschrieben. Im Fokus dieser Methodik steht es, Geschäftsprozesse als Ausgangspunkt für das Design von Services zu benutzen und deren Verbindungen zu beschreiben. Dabei orientiert sie sich an den möglichen Verbindungen, die von der Referenzarchitektur definiert werden. Um dies zu erreichen ist außerdem ein Algorithmus für das Design von Services enthalten. Dieser Algorithmus leitet aus Geschäftsprozessen Services ab und berücksichtigt dabei die Ergebnisse einer statistischen Auswertung, die die Wiederverwendbarkeit von Services als Untersuchungsziel hat. Das Ergebnis dieser Methodik ist das plattformunabhängige Design einer composite application. Dieses Design ist an einem Geschäftsprozess orientiert, berücksichtigt aber auch die Einschränkungen der Systemlandschaft, in der die Applikation betrieben werden soll. Um auf der Basis eines solchen Designs eine composite application erstellen zu können, ist weiterhin eine informelle Abbildung der plattformunabhängigen Architektur auf eine häufig eingesetzte Plattform in der Arbeit beschrieben. Zusammen mit der Methodik und der Referenzarchitektur wird diese Abbildung dann auf ein industrielles Fallbeispiel angewandt. Auf diese Weise wird die Anwendbarkeit der beschriebenen Konzepte demonstriert

Modelling Event-Based Interactions in Component-Based Architectures for Quantitative System Evaluation

This dissertation thesis presents an approach enabling the modelling and quality-of-service prediction of event-based systems at the architecture-level. Applying a two-step model refinement transformation, the approach integrates platform-specific performance influences of the underlying middleware while enabling the use of different existing analytical and simulation-based prediction techniques

Ontology-driven monitoring of patient's vital signs enabling personalized medical detection and alert

A major challenge related to caring for patients with chronic conditions is the early detection of exacerbations of the disease. Medical personnel should be contacted immediately in order to intervene in time before an acute state is reached, ensuring patient safety. This paper proposes an approach to an ambient intelligence (AmI) framework supporting real-time remote monitoring of patients diagnosed with congestive heart failure (CHF). Its novelty is the integration of: (i) personalized monitoring of the patients health status and risk stage; (ii) intelligent alerting of the dedicated physician through the construction of medical workflows on-the-fly; and (iii) dynamic adaptation of the vital signs' monitoring environment on any available device or smart phone located in close proximity to the physician depending on new medical measurements, additional disease specifications or the failure of the infrastructure. The intelligence lies in the adoption of semantics providing for a personalized and automated emergency alerting that smoothly interacts with the physician, regardless of his location, ensuring timely intervention during an emergency. It is evaluated on a medical emergency scenario, where in the case of exceeded patient thresholds, medical personnel are localized and contacted, presenting ad hoc information on the patient's condition on the most suited device within the physician's reach

Modelling Event-Based Interactions in Component-Based Architectures for Quantitative System Evaluation

This dissertation thesis presents an approach enabling the modelling and quality-of-service prediction of event-based systems at the architecture-level. Applying a two-step model refinement transformation, the approach integrates platform-specific performance influences of the underlying middleware while enabling the use of different existing analytical and simulation-based prediction techniques