115 research outputs found
Der Lösungsbeitrag von Metadatenmodellen beim Vergleich von Workflowmanagementsystemen
Die DV-gestĂŒtzte ProzeĂabwicklung mittels Workflowmanagementsystemen erlaubt die Auslagerung der Ablaufsteuerung aus Anwendungssystemen. Mittlerweile ist eine Vielzahl an Systemen mit unterschiedlicher Entwicklungsgeschichte (Dokumentenmanagement, Vorgangssteuerung etc.) verfĂŒgbar. Damit stellt sich das Problem der Auswahl eines bedarfsgerechten Workflowmanagementsystems. Im Rahmen dieses Arbeitsberichts soll der diesbezĂŒgliche Lösungsbeitrag des Vergleichs der Metadatenmodelle von Workflowmanagementsystemen evaluiert werden. Nach allgemeinen AusfĂŒhrungen zur Metamodellierung werden hierzu exemplarisch die Metadatenmodelle fĂŒr die Workflowmanagementsysteme WorkParty (SNI) und FlowMark (IBM) skizziert und verglichen.<br/
Grid service orchestration using the Business Process Execution Language (BPEL)
Modern scientific applications often need to be distributed across grids. Increasingly
applications rely on services, such as job submission, data transfer or data
portal services. We refer to such services as grid services. While the invocation
of grid services could be hard coded in theory, scientific users want to orchestrate
service invocations more flexibly. In enterprise applications, the orchestration of
web services is achieved using emerging orchestration standards, most notably
the Business Process Execution Language (BPEL). We describe our experience
in orchestrating scientific workflows using BPEL. We have gained this experience
during an extensive case study that orchestrates grid services for the automation of
a polymorph prediction application
A language and toolkit for the specification, execution and monitoring of dependable distributed applications
PhD ThesisThis thesis addresses the problem of specifying the composition of distributed applications
out of existing applications, possibly legacy ones. With the automation of business processes
on the increase, more and more applications of this kind are being constructed. The resulting
applications can be quite complex, usually long-lived and are executed in a heterogeneous
environment. In a distributed environment, long-lived activities need support for fault tolerance
and dynamic reconfiguration. Indeed, it is likely that the environment where they are run will
change (nodes may fail, services may be moved elsewhere or withdrawn) during their
execution and the specification will have to be modified. There is also a need for modularity,
scalability and openness. However, most of the existing systems only consider part of these
requirements. A new area of research, called workflow management has been trying to address
these issues.
This work first looks at what needs to be addressed to support the specification and
execution of these new applications in a heterogeneous, distributed environment. A co-
ordination language (scripting language) is developed that fulfils the requirements of specifying
the composition and inter-dependencies of distributed applications with the properties of
dynamic reconfiguration, fault tolerance, modularity, scalability and openness. The architecture
of the overall workflow system and its implementation are then presented. The system has been
implemented as a set of CORBA services and the execution environment is built using a
transactional workflow management system. Next, the thesis describes the design of a toolkit
to specify, execute and monitor distributed applications. The design of the co-ordination
language and the toolkit represents the main contribution of the thesis.UK Engineering and Physical Sciences Research Council,
CaberNet,
Northern Telecom (Nortel)
AnsÀtze zur Entwicklung von Workflow-basierten Anwendungssystemen:eine vergleichende Darstellung
Workflow-Management-Systeme werden entscheidende Impulse fĂŒr die Gestaltung von Informationssystemen der nĂ€chsten Generation geben. Ăhnlich wie Datenbank-Systeme heute werden Workflow-Systeme zukĂŒnftig als Basistechnologie in komplexen Informationssystemen verwendet werden. Sie ermöglichen eine geschĂ€ftsprozeĂnahe Darstellung der betrieblichen Ablauflogik und die explizite und zentrale Abbildung dieser GeschĂ€ftsprozeĂlogik mittels spezialisierter Softwarekomponenten im Gegensatz zu der heute ĂŒblichen impliziten Codierung der ProzeĂlogik in Applikationen. AnsĂ€tze zur Entwicklung von Workflow-basierten Anwendungen sind somit von groĂem Interesse. Anhand eines Vorgehens-Meta-Modells stellt der Beitrag zunĂ€chst wichtige in der Literatur vorgeschlagene Vorgehensmodelle zur Entwicklung von Workflow-Anwendungen einheitlich und klassifizierend dar. Darauf aufbauend erfolgt eine vergleichende Einordnung der verschiedenen AnsĂ€tze anhand von Kriterien, die basierend auf dem Meta-Modell hergeleitet werden.<br/
CORBA-Integration des Workflow-Management-Systems IBM FlowMark
Im Rahmen des Projektes 'HematoWork' sollen Workflow-Management-Systeme zur Ăerwachung von onkologischen Behandlungsabl'Ă€ufen genutzt werden. Im Rahmen des zu schaffenden Gesamtsystems werden neben dem WfMS verschiedene Applikationen eingesetzt. Als Middleware wird im Projekt die Anwendbarkeit von CORBA untersucht. Damit wurde es nötig, das Zusammenspiel von CORBA und WfMS, speziell am Beispiel von IBM FlowMark zu untersuchen. Um Methoden von CORBA-Objekten als Applikationen oder in Ăbergangsbedingungen im KontrollfluĂ von WfMS verwenden zu können, werden in der Arbeit sowohl Aspekte zur Workflow-Definitionszeit als auch zur Laufzeit untersucht. Neben einer neuen, von technischen Aspekten des CORBA- Methodenaufrufs abstrahierenden Workflow-Modellierungssprache und einem entsprechenden Compiler in die Workflow-Modellierungssprache von IBM FlowMark wurde eine Datenbank eingefĂŒhrt, die dem Management der Lebensdauer und GĂŒltigkeit von Daten, die durch CORBA-Objekte erzeugt oder reprĂ€sentiert werden, dient
Model-driven dual caching For nomadic service-oriented architecture clients
Mobile devices have evolved over the years from resource constrained devices that supported only the most basic tasks to powerful handheld computing devices. However, the most significant step in the evolution of mobile devices was the introduction of wireless connectivity which enabled them to host applications that require internet connectivity such as email, web browsers and maybe most importantly smart/rich clients. Being able to host smart clients allows the users of mobile devices to seamlessly access the Information Technology (IT) resources of their organizations. One increasingly popular way of enabling access to IT resources is by using Web Services (WS). This trend has been aided by the rapid availability of WS packages/tools, most notably the efforts of the Apache group and Integrated Development Environment (IDE) vendors. But the widespread use of WS raises questions for users of mobile devices such as laptops or PDAs; how and if they can participate in WS. Unlike their âwiredâ counterparts (desktop computers and servers) they rely on a wireless network that is characterized by low bandwidth and unreliable connectivity.The aim of this thesis is to enable mobile devices to host Web Services consumers. It introduces a Model-Driven Dual Caching (MDDC) approach to overcome problems arising from temporarily loss of connectivity and fluctuations in bandwidth
The future of enterprise groupware applications
This paper provides a review of groupware technology and products. The purpose of this review is to investigate the appropriateness of current groupware technology as the basis for future enterprise systems and evaluate its role in realising, the currently emerging, Virtual Enterprise model for business organisation. It also identifies in which way current technological phenomena will transform groupware technology and will drive the development of the enterprise systems of the future
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