Résultat de la recherche
Preserving the Context of Interrupted Business Process Activities
The capability to safely interrupt business process activities is an important requirement for advanced processaware information systems. Indeed, exceptions stemming from the application environment often appear while one or more application-related process activities are running. Safely interrupting an activity consists of preserving its context, i.e., saving the data associated with this activity. This is important since possible solutions for an exceptional situation are often based on the current data context of the interrupted activity. In this paper, a data classification scheme based on data relevance and on data update frequency is proposed and discussed with respect to two different real-world applications. Taking into account this classification, a correctness criterion for interrupting running activities while preserving their context is proposed and analyzed.
Addressing Dynamism in E-negotiations by Workflow Management Systems
Workflows (Wfs) are a major enabling technology for e-commerce. In our research, a Combined Negotiation (CN) is modeled and enacted using Wf technology. The model-ing task captures the sequencing of the individual negotia-tions as well as the dependencies between them, and the enacting task runs the model. A CN support system (CON-SENSUS) is used by the user to perform both tasks. Sup-porting dynamic modifications to the model during run-time should increase the benefits of our approach. In this paper, we highlight the need for such support by identify-ing the dynamic aspects that can occur while negotiating the different items of a package (i.e., the CN object). To address these aspects, we experimented using ADEPT, a Wf Management System supporting dynamism. This leads us to discuss the Wf Reference Model of the Wf Manage-ment Coalition, and suggest a “dynamic” extension to the current functional areas and architecture.
Dynamic Server Selection in Distributed Object Computing Systems
In this paper, we address the problem of dynamic server selection among a set of objectservers, as the ones defined by CORBA and DCOM, providing the same service type. Theseservers are not necessarily replicas but may have different interfaces and belong to differentservice providers. As a solution, we propose a novel architecture that we call LoDACE. Thisarchitecture has been designed to allow dynamic server selection and load sharing indistributed object computing environments. Specifically, the architecture prevents theoccurrence of major load imbalances that can cause failures in distributed applications. Thearchitecture is based on both the use of a trading service and the monitoring of the servers’load. Our interest in the trader is motivated by the need to discover object serversdynamically. LoDACE allows service requests to be processed by lightly loaded serversselected dynamically. The expected results are better performances in terms of responsivenessand availability of servers.
A Workflow-Oriented System Architecture for the Management of Container Transportation
In this paper, we introduce a workflow-oriented system architecture for the processing of client requests (CRs) for container transportation. In the context of multi-transfer container transportation, the processing of CRs can be achieved by specific sequences of interdependent activities. These sequences need to be just-in-time created. They also need to be adapted to deal with unexpected events that may occur. Workflow technology is used to model and to manage the processing of CRs. The creation and the adaptation of activity sequences require first, an optimized scheduling of a limited number of resources (by also respecting CRs constraints); and second, a number of special workflow concepts and functionality to correctly manage activity sequences. Optimization models are involved to take care of the resource management and of the activity scheduling. Enhancements of workflow concepts and functionality for workflow management systems are investigated to deal with an activity sequence creation and adaptation. Finally, the proposed architecture includes a rule processing part to reduce the time-consuming manual interaction with the system.
Towards Electronic Marketplaces: A Progress Report
Market design is becoming a very important research topic in the context of the electronic economy. Two factors explain this trend: (1) the creation of new markets to facilitate deregulation (telecommunication frequencies, electric power, etc.) and (2) the emergence of strategic analysis and of experimental economics. E-commerce tools will contribute to the emergence of more structured marketplaces. Private service providers will begin offering price-discovery and demand-and-supply equilibrating mechanisms. Market design issues are therefore becoming important for private e-commerce service providers. The TEM (Towards Electronic Marketplaces) project investigates issues related to the design of virtual marketplaces, whether these marketplaces are centralised or decentralised. In this paper, we present the global objectives of the TEM project, along with its specific goals, and current results. In particular, we focus on the challenges for electronic markets and on the approaches used to meet these challenges.
A Dynamic Approach to Multi-transfer Container Management
This paper introduces a dynamic approach to manage the processing of client requests in a multi-transfer container transportation (MTCT) system. At the operational level, this type of system is faced with a continuously changing environment. In this context, the need for dynamic creation and adaptation of solutions is of utmost importance. The adopted approach is based on a two-layer framework that exploits workflow technology. The latter proposes a formalism to describe sequences of activities to be enacted when processing requests, hence reducing the need for manual, time-consuming management and organi-zation. The proposed two-layer framework has a workflow layer that encapsulates the set of concurrently running workflows associated to client requests. A coordination layer is mainly responsible for the instan-tiation of new workflows to be inserted in the workflow layer and for modifications of running ones. These modifications are motivated by resource sharing issues or triggered by unanticipated/unexpected events. According to this two-layer framework, an implementation of a prototype for a MTCT system is finally presented.
The Design of a Trader based CORBA Load Sharing Service
In the context of CORBA, standard services for naming, transaction processing, and alike have been defined. However, no standard support is provided to handle load imbalances that may occur in distributed object applications where several object servers are used to provide the same service type. To address this shortcoming, we have designed a CORBA-compliant had sharing service (LSS). Preliminary experiments with LSS show that L^SS allows for the uniform load distribution among servers. Furthermore, we report that load sharing via US S performs better than the approaches based on the random and the round robin server selection methods, in terms of the average response time for client requests.