Workflow management systems (WfMSs) have been used to support various types of business processes for more than a decade now. In workflows for e-commerce and Web-services applications, suppliers and customers define a binding agreement or contract between the two parties, specifying Quality of Service (QoS) items such as products or services to be delivered, deadlines, quality of products, and cost of services. The management of QoS metrics directly impacts the success of organizations participating in e-commerce. Therefore, when services or products are created or managed using workflows, the underlying workflow system must accept the specifications and be able to estimate, monitor, and control the QoS rendered to customers. In this paper, we present a predictive QoS model that makes it possible to compute the quality of service for workflows automatically based on atomic task QoS attributes. To this end, we present a model that specifies QoS and describe an algorithm and a simulation system in order to compute, analyze and monitor workflow QoS metrics. 1

Current workflow management systems still lack support for dynamic and automatic workflow adaptations. However, this functionality is a major requirement for next-generation workflow systems to provide sufficient flexibility to cope with unexpected failure events. We present the concepts and implementation of AGENTWORK, an event-based workflow management system supporting automated workflow adaptations in a comprehensive way. In particular, AGENTWORK uses temporal estimates to determine which remaining parts of running workflows are affected by an exception and is able to predictively perform suitable workflow adaptations. This helps ensure that necessary adaptations are performed in time with minimal user interaction which is especially valuable in complex applications such as for medical treatments.

Workflow management systems (WfMSs) have been used to support various types of business processes for more than a decade now. In ecommerce processes, suppliers and customers define a binding agreement or contract between the two parties, specifying quality of service (QoS) items such as products or services to be delivered, deadlines, quality of products, and cost of service. Management of such QoS directly impacts success of organizations participating in e-commerce. Organizations operating in modem markets require an excellent degree of quality of service management. Products and services must be available to customers with well-defined specifications. A good management of quality leads to the creation of quality products and services, which in mm fulfills customer expectations and achieves customer satisfaction. Therefore, when services or products are created or managed using workflow processes, the underlying WfMS must accept the specification, be able to predict, monitor, and control the QoS rendered to customers. To achieve these objectives the first step is to develop an adequate QoS model for workflow processes and develop methods to compute QoS.

Abstract not found

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. 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.

Abstract. In grid workflow systems, existing representative checkpoint selection strategies, which are used to select checkpoints for verifying fixed-time constraints at run-time execution stage, often select some unnecessary checkpoints and ignore some necessary ones. Consequently, overall temporal verification efficiency and effectiveness can be severely impacted. In this paper, we propose a new strategy that selects only necessary and sufficient checkpoints dynamically along grid workflow execution. Specifically, we introduce a new concept of minimum time redundancy as a key reference value for checkpoint selection. We also investigate its relationships with fixed-time constraint consistency. Based on these relationships, we present our strategy which can improve overall temporal verification efficiency and effectiveness significantly. 1

Abstract. Grid workflow systems aim to support large-scale complex e-science and e-business processes. Due to the complexity of these kinds of processes, to control the execution of them in terms of time in the grid workflow execution environment, multiple fixed-date temporal constraints often need to be set simultaneously. Hence the dependency problem between them must be considered and emphasised, which affects the verification effectiveness and efficiency of the fixed-date temporal constraints. However, current relevant workflow verification works do not take into consideration this dependency. Therefore, in this paper, we explore it in depth and investigate its impact on the verification of the fixed-date temporal constraints. Furthermore, based on the temporal dependency, we develop some new temporal verification methods and algorithms. The comparison and evaluation show that these new methods and algorithms make the verification more effective and efficient. All these analyses, new methods and algorithms further strengthen the grid workflow time management. Keywords: Grid workflow, Fixed-date temporal constraints, Temporal dependency, Temporal verification 1

Abstract. The current workflow management systems do not take into consideration the mutual dependency between temporal constraints, which is affecting the effectiveness and efficiency of the temporal verification. In this paper, we investigate this dependency and its effects on the verification of temporal constraints. Furthermore, based on these analyses on the temporal dependency, we develop some new methods for more effective and efficient temporal verification. These analyses and new methods further reinforce the time management of the current workflow management systems. 1

Abstract Web-based interorganizational workflows need efficient time management. Variations of activity durations and branching distributions on or-split nodes make it necessary that we treat time management in workflows in a probabilistic way. We introduce the notion of duration histograms for capturing the available temporal information about workflow execution, define the necessary operations for computing timed execution plans for workflows and discuss the application of this new concepts for workflow design as well as time aware workflow execution management.