Security Mechanisms for Workflows in Service-Oriented Architectures

Die Arbeit untersucht, wie sich Unterstützung für Sicherheit und Identitätsmanagement in ein Workflow-Management-System integrieren lässt. Basierend auf einer Anforderungsanalyse anhand eines Beispiels aus der beruflichen Weiterbildung und einem Abgleich mit dem Stand der Technik wird eine Architektur für die sichere Ausführung von Workflows und die Integration mit Identitätsmanagement-Systemen entwickelt, die neue Anwendungen mit verbesserter Sicherheit und Privatsphäre ermöglicht

Patterns-based Evaluation of Open Source BPM Systems: The Cases of jBPM, OpenWFE, and Enhydra Shark

In keeping with the proliferation of free software development initiatives and the increased interest in the business process management domain, many open source workflow and business process management systems have appeared during the last few years and are now under active development. This upsurge gives rise to two important questions: what are the capabilities of these systems? and how do they compare to each other and to their closed source counterparts? i.e. in other words what is the state-of-the-art in the area?. To gain an insight into the area, we have conducted an in-depth analysis of three of the major open source workflow management systems - jBPM, OpenWFE and Enhydra Shark, the results of which are reported here. This analysis is based on the workflow patterns framework and provides a continuation of the series of evaluations performed using the same framework on closed source systems, business process modeling languages and web-service composition standards. The results from evaluations of the three open source systems are compared with each other and also with the results from evaluations of three representative closed source systems - Staffware, WebSphere MQ and Oracle BPEL PM, documented in earlier works. The overall conclusion is that open source systems are targeted more toward developers rather than business analysts. They generally provide less support for the patterns than closed source systems, particularly with respect to the resource perspective which describes the various ways in which work is distributed amongst business users and managed through to completion

Supporting Virtual Enterprise Systems Using Agent Coordination

International audienceOpen environments like the Internet or corporate intranets enable a large number of interested enterprises to access, filter, process, and present information on an as-needed basis. These environments support modern applications, such as virtual enterprises and inter-organizational workflow management systems, which involve a number of heterogeneous resources, services, and processes. However, any execution of a virtual enterprise system would yield to disjoining and error-prone behavior without appropriate techniques to coordinate the various business processes. This paper reports on the design and implementation of a flexible agent-based framework for supporting the coordination of virtual enterprises and workflow management systems. The paper also shows how an agent coordination infrastructure, which is explained by social constraints, can impact on the engineering of highly dynamic virtual enterprises and workflow management systems by presenting a simple case study

A Secure Task Delegation Model for Workflows

International audienceWorkflow management systems provide some of the required technical means to preserve integrity, confidentiality and availability at the control-, data- and task assignment layers of a workflow. We currently observe a move away from predefined strict workflow enforcement approaches towards supporting exceptions which are difficult to foresee when modelling a workflow. One specific approach for exception handling is that of task delegation. The delegation of a task from one principal to another, however, has to be managed and executed in a secure way, in this context implying the presence of a fixed set of delegation events. In this paper, we propose first and foremost, a secure task delegation model within a workflow. The novel part of this model is separating the various aspects of delegation with regards tousers, tasks, events and data, portraying them in terms of a multi-layered state machine. We then define delegation scenarios and analyse additional requirements to support secure task delegation over these layers. Moreover, we detail a delegation protocol with a specific focus on the initial negotiation steps between the involved principals

Integrating Groupware Activities into Workflow Management Systems

Computer supported cooperative work (CSCW) has been recognized as a crucial enabling technology for multi-user computer-based systems, particularly in cases where synchronous human-human interaction is required between geographically dispersed users. Workflow is an emerging technology that supports complex business processes in modern corporations by allowing to explicitly define the process, and by supporting its execution in a workflow management system (WFMS). Since workflow inherently involves humans carrying out parts of the process, it is only natural to explore how to synergize these two technologies. We analyze the relationships between groupware and workflow management, present our general approach to integrating synchronous groupware tools into a WFMS, and conclude with an example process that was implemented in the Oz WFMS and integrated such tools. Our main contribution lies in the integration and synchronization of individual groupware activities into modeled workflow processes, as opposed to being a built-in part of the workflow WFMS

Knowledge based approach to flexible workflow management systems

This thesis was submitted for the degree of Doctor of Philosophy and awarded the Korea Advanced Institute of Science and Technology (KAIST).Today's business environments are characterized by dynamic and uncertain environments. In order to effectively support business processes in such contexts, workflow management systems must be able to adapt themselves effectively. In this dissertation, the workflow is redefined in concept and represented with a set of business rules. Business rules play a central role in organizational workflows in context of cooperation among actors. To achieve business goals, they constrain the flow of works, use of resources, and responsibility mapping between tasks and actors using role concept. Business rules are explicitly modeled in the Knowledge-based Workflow Model (KWM) using frames. To increase the adaptability of workflow management system, KWM has several distinctive features. First, it increases expressiveness of workflow model so that exception handling rules and responsibility mapping rules between tasks and actors as well as task scheduling rules are explicitly modeled. Secondly, formal definition of KWM enables one to define and to analyze correctness of workflow schema. Knowledge-based approach enables more powerful analysis on workflow schema including checking consistency and compactness of routing rules as well as terminality of a workflow. Thirdly, providing change propagation mechanism which assures correctness of workflow after the modification of workflow schema increases adaptability. Change propagation rules for the modification primitives are provided to manage workflow evolution. On the other hand, metarules that control rules in KWM are used to handle exceptions that occur in a running workflow instance. Workflow participants can easily change workflow schema of a workflow instance with the support of extra rules and a metarule. Based on KWM, K-WFMS (Knowledge-based WorkFlow Management System) has been implemented in client/server architecture. Inference shell of knowledge-based systems is employed for enactment of business rules and integrated with database systems. From a real application based on the KWM architecture, it has been shown that system performance can increase notably by reducing the number of rules and facts that are used in the course of workflow enactment