this paper may be "long running" or not. Other related terms used in the database literature are task flow, multitransaction activities [7], multi-system applications [1], application multiactivities, and networked applications [4]. Some related issues are also addressed in various relaxed transaction models.

Workflow systems hold the promise of facilitating the everyday operation of many enterprises and work environments. As a result, many commercial workflow management systems have been developed. These systems, although useful, do not scale well, have limited fault-tolerance, and are inflexible in terms of interoperating with other workflow systems. In this paper, we discuss the limitations of contemporary workflow management systems, and then elaborate on various directions for research and potential future extensions to the design and modeling of workflow management systems. 1 Introduction Workflow management is one of the areas that, in recent years, has attracted the attention of many researchers, developers and users. For the users, it has finally made commercially available tools and functionality for which there has been an important demand for quite some time. Concepts such as computer supported cooperative work, paperless office, form processing, cooperative systems, and offic...

The full potential of the web as a medium for electronic commerce can be realized only when multiple partners in a supply chain can route information among themselves in a seamless way. Commerce on the Internet is still far from being "friction-free" because business partners cannot exchange information about their business processes in an automated manner. In this paper, we propose the design for an eXchangeable Routing Language (XRL) using XML syntax. XML (eXtendible Markup Language) is a means for trading partners to exchange business data electronically. The novel contribution of our work is to show how XML can also be used to describe workflow process schemas to support flexible routing of documents in the Internet environment. The design of XRL is grounded in Petri nets, which is a wellknown formalism. By using this formalism, it is possible to analyze correctness and performance of workflows described in XRL. Architectures to facilitate inter-operation through loose and tight integration are also discussed. Examples illustrate how this approach can be used for implementing interorganizational electronic commerce applications. As a proof of concept we have also developed XRL/flower, a prototype implementation of a workflow management system based on XRL.

We present a replication-based approach to fault-tolerant distributed stream processing in the face of node failures, network failures, and network partitions. Our approach aims to reduce the degree of inconsistency in the system while guaranteeing that available inputs capable of being processed are processed within a specified time threshold. This threshold allows a user to trade availability for consistency: a larger time threshold decreases availability but limits inconsistency, while a smaller threshold increases availability but produces more inconsistent results based on partial data. In addition, when failures heal, our scheme corrects previously produced results, ensuring eventual consistency. Our scheme uses a data-serializing operator to ensure that all replicas process data in the same order, and thus remain consistent in the absence of failures. To regain consistency after a failure heals, we experimentally compare approaches based on checkpoint/redo and undo/redo techniques and illustrate the performance trade-offs between these schemes. 1.

this paper we present the Exotica Research Project, currently in progress at the IBM Almaden Research Center. One of the goals of the project is to bring together industrial trends and research issues in the workflow area. It is for this reason that we have focused on a particular commercial product, FlowMark, IBM's workflow product. However, our results are easily generalized to general workflow management systems since FlowMark's y

This paper presents five run-time architectures for implementing a Workflow Management System (WFMS). The architectures range from highly centralized to fully distributed. Two of the architectures have been implemented at the Large Scale Distributed Information Systems (LSDIS) Lab at The University of Georgia. All the WFMS architectures are designed on top of a Common Object Request Broker Architecture (CORBA) implementation. The paper also discusses the advantages and disadvantages of the architectures and the suitability of CORBA as a communication infrastructure. A minor extension to CORBA's Interface Definition Language (IDL) is proposed to provide an alternative means of specifying workflows. Simplified examples from the healthcare domain are given to illustrate our technology. 1 1 INTRODUCTION Competition and economic pressures force modern business corporations to look for new information technologies to support their business process management. Since workflow technology prov...

Key limitations of the state-of-art workflow products and research prototypes include the lack of adequate support for functioning in heterogeneous environments that involve humans and automated tasks distributed across enterprises, limited scalability, and the lack of adequate support for dealing with errors and failures in real-world organizational settings. Emergence of network computing based on Web and distributed object management provide an attractive infrastructure to address these issues. Workflow management techniques developed in the METEOR 2 project are intended to reliably support coordination of user and automated tasks in real-world multi-enterprise heterogeneous computing environments. Key capabilities of the METEOR 2 workflow management system (WFMS) include a comprehensive toolkit for building workflows (map/data/task design) and supporting high-level process modeling, detailed workflow specification, and automatic code generation for its workflow enactment ...

Workflow Management Systems (WFMS) are a first generation of products that attempt to manage the execution of business processes by large numbers of users distributed over a wide area and using heterogeneous resources. They are a very promising venue for collaborative systems but, in most cases, the autonomy of the users is greatly restricted due to architectural and design considerations. This is a severe restriction, especially when considering the emergence of mobile computing, and the increase in use of laptops and small computers which are connected to a network only occasionally. In this paper, we discuss how disconnected workflow clients can be supported while preserving the correctness of the overall execution and allowing coordinated interactions between the different users. Disconnected client support provides a great deal of flexibility in the usability of a WFMS and enhances the system's resilience to failures. 1 Introduction The recent increase in the availability of pow...

This dissertation proposes micro-workflow, a new workflow architecture that bridges the gap between the type of functionality provided by current workflow systems and the type of workflow functionality required in object-oriented applications. Micro-workflow provides a better solution when the focus is on customizing the workflow features and integrating with other systems. In this thesis I discuss how micro-workflow leverages object technology to provide workflow functionality. As an example, I present the design of an object-oriented framework which provides a reusable micro-workflow architecture and enables developers to customize it through framework-specific reuse techniques. I show how through composition, developers extend micro-workflow to support history, persistence, monitoring, manual intervention, worklists, and federated workflow. I evaluate this approach with three case studies that implement processes with different requirements

Internet-based electronic commerce is becoming the next frontier of new business opportunities. However, commerce on the Internet is seriously hindered by the lack of a common language for collaborative commercial activities. Although XML (Extensible Markup Language) allows trading partners to exchange semantic information electronically, it does not provide support for document routing. In this paper, we describe various interorganizational electronic commerce applications and discuss their needs for workflow support. Then, we propose a blueprint for XRL, an Extensible Routing Language that enables routing of commercial documents over the Internet and helps in creating truly intelligent documents. This routing language is simple, yet powerful enough to support flexible routing of documents in the Internet environment. 1. Introduction The Internet and the World Wide Web (WWW) have changed the landscape of networked computing and have become the de facto environment for electronic co...