Eleanna Kafeza

Workflow View Based E-Contracts in a Cross-Organizational E-Services Environment

In an e-service environment, workflow involves not only a single organization but also a number of business partners. Therefore, workflow inter-operability in such an environment is an important issue for enacting workflows. In this article, we introduce our approach of using workflow views as a fundamental support for E-service workflow inter-operability and for controlled visibility of (sub-)workflows by external parties. We discuss various aspects of a workflow view, and their semantics with example usage. Furthermore, we develop a contract model based on workflow views and demonstrate how management of e-contracts can be facilitated, with an Internet start-up E-service inter-organization workflow example.

View-Based Contracts in an E-Service Cross-Organizational Workflow Environment

In an e-service environment, workflow involves not only a single organization but also a number of business partners. Workflow interoperability is therefore an important issue for workflow enactment in such an environment. In this paper, we introduce a novel concept of workflow views as a fundamental support for E-service workflow inter-operability and for controlled visibility by external parties. Furthermore, we develop a contract model based on workflow views and demonstrate how management of contracts can be facilitated, with an Internet start-up E-service inter-organization workflow example.

Temporally Constrained Workflows

Although temporal aspects during a workflow execution are of major importance, it is only recently that the problem of temporal coordination of workflow activities is being addressed. As the demand for time management in workflow applications increases, temporal coordination can no longer be limited to being a result of value dependencies between activities. It must be conceptualized, modeled and supported as a part of the WFMS. In this work, we propose a temporal process specification model and develop formalism to determine the consistency of the specification. In the execution level, we show that finer control on activities execution can be achieved by exploiting their temporal constraints. Furthermore, we discuss different scheduling policies to illustrate the trade-off between temporal-constraint violation and missed deadline.

Speeding Up CapBasED-AMS Activities through Multi-Agent Scheduling

Activity management systems have been employed in large organization to facilitate production time business processes (or workflows). An activity consists of interdependent tasks. Exactly one agent (human, hardware/software system) executes a task. CapBasEDAMS is a capability based and event driven activity management system that supports specification and execution of activities using cooperative information systems paradigm. For each business process to be executed an activity instant is created and executed in CapBasEDAMS. Each task of an activity instant is assigned to an agent that executes the task. Therefore, when there are many activity instances executing at the same time many tasks are queued up at agents for execution. In order to speed up the completion of business process, the user can request that certain activity instances be speeded up. In this paper, we design algorithms for speeding up multiple activity instances at the same time by rescheduling activities in multiple agent queues. We evaluate these algorithms for both one-time speed up and multiple times speed up. Our results show that the multiple speed-up algorithm outperform the one-time speed-up algorithm.

Speeding up electronic commerce activities using CapBasED-AMS

CapBasED-AMS is a capability based and event driven activity management system that supports specification and execution of activities using the cooperative information systems paradigm. In CapBasED, an activity consists of interdependent tasks (atomic activities) that are executed by an agent. When there are many activity instances executing at the same time many tasks are queued up at agents for execution. In this paper, we propose a multi-agent system model, introduce a measurement of speed-up/slow-down, and develop different scheduling policies that allow for faster executions based on users requests. Our scheduling framework is developed under the assumption that there are no additional resources for speeding-up the activities and it is based on re-scheduling activities in agents queues.

Gaining Control over Time in Workflow Management Applications

The need for explicit time management in workflow environments has been recently identified. Although the concept of time is inherent in workflow applications, time management until now has been treated by the same general-purpose structures of the workflow system. This traditional approach does not allow for explicitly specifying timing correctness requirements, temporal consistency checking, immediate control over the diverse set of time constraints that workflow applications exhibit and timely monitoring of the environment. In this paper, we extend the existing workflow specification based on the requirements posed by real-life applications such as health systems. We argue that time management should be an integral part of the workflow management system and not performed by a general-purpose temporal reasoner. We incorporate a subset of interval algebra that allows for efficient consistency checking, while providing expressiveness of temporal constraints. We show that static scheduling for meeting temporal constraints is inadequate for a large class of workflow applications. We show how global scheduling based on temporal constraints can be combined with agent scheduling policies. We demonstrate through examples the working of the scheduling algorithms.

A framework for speeding up workflow instances by exploiting alternate paths

Workflow systems have been deployed in organizations to facilitate efficient, consistent, and accurate handling of business processes. As in real life, there are many different ways to do work, with varying cost and completion times. We augment workflow systems by providing modelling support for alternate paths with models for calculating the completion times and the cost for executing a workflow. Further, we design scheduling algorithms to facilitate execution of workflow instances to meet user requirements on completion times and cost of execution.