Showing papers by "Dimitrios Georgakopoulos published in 2000"

Modeling and Composing Service-Based nd Reference Process-Based Multi-enterprise Processes

Abstract: Multi-enterprise processes (MEPs) are workflows consisting of a set of activities that are implemented by different enterprises Tightly coupled Virtual Enterprises (VEs) typically agree on abstract MEPs (reference MEPs), to which each enterprise contributes single-enterprise processes (SEPs) that implement and refine the activities in the reference MEP On the other end of the spectrum, loosely coupled VEs use service-based MEPs that fuse together heterogeneous services implemented and provided by different enterprises Existing process models usually couple activities with their implementation Therefore, they cannot effectively support such MEPs In this paper, we introduce a Polymorphic Process Model (PPM) that supports both reference process- and service-based MEPs To accomplish this, PPM decouples activity interface from activity implementation, and provides process polymorphism to support their mapping In particular, PPM determines activity types from the activity interfaces, permits activity interface subtyping, and provides for the mapping of MEP activity types to concrete implementations via interface matching We illustrate that these key PPM capabilities permit the late binding and use of multiple activity implementations within a MEP without modifying the MEP at run time or enumerating the alternative implementation at specification time

Workflow Migration Supporting Virtual Enterprises

Abstract: Multi-enterprise processes (MEPs) are the means by which Virtual Enterprises (VEs) may efficiently coordinate their resources and establish and manage their supply chains. The Collaboration Management Model (CMM) developed in MCC provides a framework for modeling and implementing MEPs. In this paper we propose to extend the CMM with workflow migration, that is, with the ability of workflows to transfer their code and execution state to another host during run time. This permits the enterprises in a VE to agree upon abstract workflows that consist of placeholder activities capturing the need for inter-enterprise services. Abstract workflow execution involves its migration to the enterprise sites that provide the services its requires. At each such site, abstract workflow execution involves (1) refinement and extension of activity placeholders based on local knowledge and (2) enactment of the resulting concrete workflows. The migration of workflows improve the collaboration between organizations with strong local decision autonomy and specialization, since it allows refining the workflow specification during its execution and enables dynamic choices of different implementations of the same activities. The migrating workflows are naturally suitable for mobile environments, where disconnection of hosts is normal and the network bandwidth is at premium.

Process-based service integration for zero latency supply chains in virtual enterprises

Abstract: Supply chains provide composite services or products by utilizing autonomous, heterogeneous and/or conversational services provided by independent enterprises. In this paper, we propose a service-oriented process (SOP) model that can model and construct efficient multi-enterprise supply chains as multi-enterprise processes (MEPs). In particular, the SOP model supports service activities for modeling the services themselves, primitives for composing supply chains from services, and primitives for automating service coordination as required by a supply chain. One of the most important aspects of service modeling in SOP is decoupling the service interface from the service implementation. This enables MEPs and the corresponding supply chains to include placeholders, i.e. activities specified only by an abstract interface. These placeholders are substituted at run-time with one of the available services that implement the specified abstract interface. The SOP service selection policy uses a semantic broker that has knowledge about the service capabilities and quality. Therefore, a MEP (and hence its supply chain) is capable of on-the-fly choice of the service providers that are best suited to its objectives (e.g. cheapest, fastest, or just available).