Managing Modern Organizations With Information Technology 267 Copyright © 2005, Idea Group Inc. Copying or distributing in print or electronic forms without written permission of Idea Group Inc. is prohibited. A Comparative State-of-the-Art for Flexible Workflow Modeling Selmin Nurcan Université Paris 1 - Panthéon - Sorbonne, Centre de Recherche en Informatique, 90, rue de Tolbiac 75634 Paris cedex 13 France nurcan@univ-paris1.fr Awatef Hicheur CNAM, 292 rue Saint-Martin 75141 Paris cedex 03 France, a_hicheur@yahoo.fr ABSTRACT Durring the early 90’s, workflow technologies were the only ones to offer a transversal integration capacity to the enterprise applications. However, formalisms proposed for workflow specifications were almost systematically activity oriented. Most of the usual modeling formal- isms, as well as standards defined by WfMC, are all based on organiza- tional and operational concepts. Consequently, resulting process defi- nitions have the advantage to be easily transformable in executable code but the disadvantage of being prescriptive and rigid. More recent works highlight requirements in term of flexible and adaptive workflows, whose execution can evolve according to situations that cannot always be prescribed. This paper presents the state of the art for flexible workflow management systems and criteria for comparing them. It also introduces a conceptual framework for flexible business process modeling. INTRODUCTION In all management challenges, information systems should be continu- ously adapted to changing business practices and needs. This can be achieved by developing process-centric solutions. The paradigm of ‘Business Process Management’ stresses the importance of integrating entire processes rather than simply integrating data or applications [6]. The process-oriented business management requires appropriate con- cepts to design business processes and their supporting IS. The aim is to define and control the organizational structures in a flexible way so they can rapidly evolve according to changing conditions. Since the beginning of the application of the Business Process Reengineering [13] as a management method for transforming organi- zations, Workflow Management Systems (WFMS) have often been positioned as an appropriate technological solution to satisfy the objectives set by this management method. Workflow technologies allow integrating process islands at a high level so that they can collaboratively provide business solutions that each individual applica- tion is unable to provide. However commercial workflow solutions offer only limited evolution facilities. The objective of the research in progress is measure the capacity of the studied modeling formalisms to represent various types of business processes and to support their evolution. This paper is organized as follows: Section 2 discusses some limits of the current workflow technologies which offer an automated support to the enactment of business processes. Section 3 presents a survey on flexible workflow modeling. Section 4 gives an overview of our conceptual framework which allows us to describe the invariants (or the minimal definition) of business processes before specifying the manner of making them operational in particular organizational contexts. AUTOMATED SUPPORT FOR DEFINING AND EXECUTING BUSINESS PROCESSES Business processes can be roughly classified into two categories. The first concerns well-defined and -often- repetitive processes having impor- tant coordination and automation needs. The second category concerns ill-defined processes. The essential preoccupation with the latter is the information and knowledge sharing between the actors implied in the processes more than the coordination of their tasks. For many organi- zations, well-defined and ill-defined processes coexist and must be handled in the final business model [25]. According to [38], a process definition is “the representation of a business process in a form that supports automated manipulation, such as modelling or enactment by a WFMS. The process definition consists of a network of activities and their relationships, criteria to indicate the start and termination of the process, and information about the individual activities, such as participants performing them, IT applica- tions supporting them, etc”. This definition corresponds to a prescrip- tive process model in the sense that “how things must/should/could be done” should be pre-defined before the enactment of the process definition. By opposition, a descriptive process model aims at recording and providing a trace of what happens during the business process [12]. Several classifications have been proposed for workflow applications. The commonly used divides them into four classes, depending on the nature of the business processes they support and the value these processes have for the enterprise [2]: • Production workflows involve repetitive and predictable business processes. They implement the core processes of the enterprise and incorporate accesses to various information systems. They form the closest category to the existing commercial WFMS solutions and the generic workflow product structure adopted by WfMC [38]. • Administrative workflows involve repetitive, predictable processes with simple task coordination rules and do not concern the core processes of the enterprise. • Ad hoc workflows have no predefined structure. Workflow support is limited to communication mechanisms to route case data between workers and possibly some support for logging and state tracking. They are created to deal with exceptions, or where there is no set pattern for moving information among people. The coordination of the activities is controlled by human participants. • Collaborative workflows, unlike the other categories, includes iterative tasks over the same step until some form of agreement has been made. It seems very difficult to model such a process using classical WFMSs since it is impossible to predefine the steps to follow. Most of the co-ordination is done by human participants. Most of the existing workflow modelling formalisms are prescriptive ones. In terms of automated support for executing business process 701 E. Chocolate Avenue, Suite 200, Hershey PA 17033, USA Tel: 717/533-8845; Fax 717/533-8661; URL-http://www.idea-group.com ITP5180 IDEA GROUP PUBLISHING This paper appears in Managing Modern Organizations Through Information Technology, Proceedings of the 2005 Information Resources Management Association International Conference, edited by Mehdi Khosrow-Pour. Copyright 2005, Idea Group Inc.