New mobile technologies such as Bluetooth or Wi-Fi suffer from many limitations and problems, especially when they are used in combination, whereas they are quite stable in small networks. The lack of specialised mobi...
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New mobile technologies such as Bluetooth or Wi-Fi suffer from many limitations and problems, especially when they are used in combination, whereas they are quite stable in small networks. The lack of specialised mobile middleware requires new methods in the design and execution of mobile information systems. We propose a two-phase approach to manage a mobile business process by partitioning a given workflow into several workflows, with each one governed by a controller. In the first phase, we introduce synchronisation tasks between different controllers. In the second phase, we create for each controller a local process view. Thanks to added tasks, the overall execution of all local workflows achieve the same result as the original one. The mobile scenario and the necessity for more automation lead us to choose the Business Process Execution Language for Web Services (BPEL4WS) as the language for the process definition.
The design and implementation of a workflow management system is typically a large and complex task. Decisions need to be made about the hardware and software platforms, the data structures. the algorithms, and networ...
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The design and implementation of a workflow management system is typically a large and complex task. Decisions need to be made about the hardware and software platforms, the data structures. the algorithms, and network interconnection of various modules utilized by various users and administrators. These decisions are further complicated by requirements such as flexibility robustness, modifiability, availability, performance, and usability. As the size of workflow systems increases, organizations (ire finding that the standard server/client architectures, and off-the-shelf solutions are not adequate. We can further see that in the future, vend large-scale work-flow systems (VLSW) will become more complex, and more prevalent. Thus, one fia-ther requirement is an emphasis of this document: scalability. For the purposes of our scalable workflow investigations, we describe a framework. a taxonomy, a model, and a methodology to investigate the performance of various workflow architectures as the size of the system (number of workcases) grows very large. First, this paper presents a novel workflow architectural framework and taxonomy. We survey some example current workflow products and research prototype systems, illustrating some of the taxonomical categories. In fact. most current workflow architectures fall into only one of the many categories of this taxonomy: the centralized server/client category. The paper next explains a performance analysis methodology useful,for exploring this taxonomy. The methodology deploys a layered queuing model, and performs mathematical analysis on this model using a modified MOL me(hod of layers) combined with a linearization algorithm. Finally. the paper utilizes this methodology to compare rind contrast the various architectural categories, providing interesting results about performance as the number of workcases increases. Our analytic results suggest that (a) for VLSW performance determination. software architecture is as important
Support of distributed workflow execution and scalability are important issues for workflow management systems. Many cooperating workflow servers should build up a distributed workflow management system to meet the re...
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This paper describes WebFlow, an environment that supports distributed coordination services on the World Wide Web. WebFlow leverages the HTTP Web transport protocol and consists of a number of tools for the developme...
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This paper describes WebFlow, an environment that supports distributed coordination services on the World Wide Web. WebFlow leverages the HTTP Web transport protocol and consists of a number of tools for the development of applications that require the coordination of multiple, distributed servers. Typical applications of WebFlow include distributed document workspaces, inter/intra-enterprise workflow, and electronic commerce. In this paper we describe the general WebFlow architecture for distributed coordination, and then focus on the environment for distributed workflow.
The OSF distributed Computing Environment (DCE) has been established as an industry standard for open distributed computing based on the client/server model. Using the case of a distributed workflow approach, it is sh...
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The OSF distributed Computing Environment (DCE) has been established as an industry standard for open distributed computing based on the client/server model. Using the case of a distributed workflow approach, it is shown that DCE is a sound technological base, but that an extended higher-level object-oriented system support is better suited for such applications. Based on these observations, experiences with the distributed object-oriented environment DC++ on top of DCE are presented. The main goal of this system case study is to illustrate how a conventional distributed environment such as DCE can be enhanced with object interaction mechanisms and object mobility support without specific system-level modifications. Finally, future requirements and current research directions for supporting mobile communication in the context of distributed object-oriented systems are outlined.
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