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Market-Based Workflow Management

Andreas Geppert, Markus Kradolfer, Dimitrios Tombros

Technical Report 97.15
November 1997

Department of Computer Science, University of Zurich


This paper presents market-based workflow management, a novel approach to workflow specification and execution which regards activities contained in a workflow as goods traded on an electronic market. Information about expected cost and execution time is considered for activity specifications, and is used at runtime to execute workflows such that actual cost and execution times are balanced and optimized. To that end, task assignment uses a bidding protocol, in which each eligible processing entity specifies at which price and in which time interval he/she can execute the activity. The winner of a specific bidding process is requested execute the activity, and earns the amount specified in the corresponding bid. Market-based workflow management thus not only allows to optimize workflow executions with respect to execution time and overall cost; but the trading of activities represents an incentive for processing entities to engage in a workflow.

1 Introduction and Motivation

Workflow management has recently found great attention in the information systems field, as it allows to capture knowledge about business processes, to define workflows in a formal language/framework, and to enact workflows according to their specification. Hereby, a workflow specification defines the structure of workflows (e.g., atomic activities/steps), processing entities responsible/capable of executing these activities, and further constraints such as execution or temporal dependencies. Workflow management systems (WFMS) are the software systems that support the specification and the execution of workflows.

Workflow management is often pursued as a consequence of business process reengineering, which attempts to restructure and optimize processes, to improve the quality of services and products, and to decrease time to market. Inherent to these objectives is the notion of optimality in the sense that a process should produce the same result at a lower cost and/or in a shorter time than was possible before process redesign. Alternatively, a result of a higher quality may be produced, in which case quality has to be defined in a business-dependent way.

Some WFMS allow the definition of expected execution times and costs for workflows (e.g., Ultimus [21]) which can be used for simulation purposes. Others are able to recognize that a workflow will probably not meet a deadline, and can then try to ?escalate? the workflow execution [15]. However, the objective of cost/time optimization is typically not addressed by WFMS, neither at the workflow specification nor at the execution level.