A workflow is an activity involving the coordinated execution of multiple tasks performed by different processing entities [KS95]. These tasks could be manual, or automated, either created specifically for the purpose of the workflow application being developed, or possibly already existing as legacy

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 ...

Workflows management systems support the definition and execution of business processes. While business process reeingeneering tools use time information to simulate and optimize processes, the management of time is hardly supported in workflow systems. We introduce a concept for time management for workflow systems. It consists of calculating internal deadlines for all activities within a workflow, checking time constraints and monitoring time at run-time. For the calculation of internal deadlines we extend the netdiagram technique PERT to support the structures usually found in workflows. At run-time this time information is used to pro-acticely avoid time errors and reactively resolve time failures. The concept has been implemented in our prototype workflow management system Panta Rhei. 1

Abstract. In this article a general business process architecture is presented, which is based on the Architecture of Integrated Information Systems (ARIS) and which is composed of the four levels of process engineering, process planning and control, workflow control and application systems. The ARIS-House of Business Engineering encompasses the whole life-cycle range: from business process design to information technology deployment, leading to a completely new process-oriented software concept. At the same time, the architecture bridges the gap between business process modeling and workflow-driven applications,

We present the prototypical workflow management system Panta Rhei which was designed to support various types of workflows in an uniform and elegant way. The main characteristics of this system are its flexibility, the lean architecture, the integration in the Web, the transactional features and its support of process management. We discuss the basic concepts of the system, its architecture and its implementation.

Web-based workflow systems have recently received much attention because they can support dynamic business processes over heterogeneous computing systems. Most existing web-based workflow systems, however, provide minimal security services such as authentication of users and network security. In this paper we describes an experiment in injecting role-based access control (RBAC) into an existing web-based workflow system. Specifically, we ensure that each task can only be executed by users belonging to a specific role. In order to achieve this, we define a simplified RBAC model to meet our needs and describe the security architecture to be applied to an existing web-based workflow system. We describe our implementation using commercial off-the-shelf (COTS) technology to demonstrate the feasibility of this approach. Our implementation uses X.509v3 certificates with role attribute, and employs a user-pull style where the client requests a client certificate from the role-server and presen...

Abstract. Hermes is a middleware system for design and execution of activity-based applications in distributed environments. It supports mobile computation as an application implementation strategy. While middleware for mobile computing has typically been developed to support physical and logical mobility, Hermes provides an integrated environment where application domain experts can focus on designing activity workflow and ignore the topological structure of the distributed environment. Generating mobile agents from a workflow specification is the responsibility of a context-aware compiler. Hermes is structured as a component-based, agent-oriented system with a 3-layer software architecture. It can be configured for specific application domains by adding domain-specific component libraries. The Hermes middleware layer, compilers, libraries, services and other developed tools together result in a very general programming environment, which has been validated in two quite disparate application domains, one in industrial control and the other in bioinformatics. In the industrial control domain, embedded systems with scarce computational resources control product lines. Mobile agents are used to trace products and support selfhealing. In the bionformatics domain, mobile agents are used to support data collection and service discovery, and to simulate biological system through autonomous components interactions. 1

Even though currently available workflow management systems (WFMSs) offer sophisticated modeling tools for specifying and analyzing workflow processes, their time management support is rudimentary. Existing time management functionality mainly addresses process simulations (to identify process bottlenecks, analyze execution durations, etc.), assignment of deadlines to activities, and triggering of process-specific exception-handling activities (referred to as escalations) when deadlines are missed during process execution. In this paper, we address the crucial role of time management in the lifecycle of workflow processes. In particular, we describe how structural (i.e. execution order dependent) and explicit (i.e. fixed-date, periodic, upper- and lowerbound) time constraints can be modeled during process definition, validated during modeling and instantiation-times and, finally, monitored and managed during execution time. 1

Abstract. This paper describes a process-algebraic approach to specification and refinement of workflow processes. In particular, we model both specification and implementation of workflows as CSP processes. CSP’s behavioural models and their respective refinement relations not only enable us to prove correctness properties of an individual workflow process against its behavioural specification but also allows us to design and develop workflow processes compositionally. Moreover, coupled with CSP is an industrial strength automated model checker FDR, which allows behavioural properties of workflow models to be proved automatically. This paper details some CSP models of van der Aalst et al.’s control flow workflow patterns, and illustrates behavioural specification and refinement of workflow systems with a business process scenario. 1

Abstract. Personal schedules allow workflow participants to improve their performance of activity executions. Participants are no longer surprised by the entries in their work-lists but receive advance information about (potential) future activity assignments, allowing better possibilities for work-planning. The personal schedule system is based on a probabilistic workflow time management system using duration histograms. A personal schedule collects future activity assignments together with their probability and their timing requirements and allows to analyze the workload of a participant and to support the scheduling of activities with the goal of reduced turn-around times and reduced number of violations of temporal constraints.