Surveying Workflow Modeling Techniques Ahmed Mohamed Gamal-Edeen Teaching Assistant Department of Information Systems Al-Obour High Institute for Management, and Informatics Galal Hassan Galal-Edeen, PhD Associate Professor of Information Systems Head, Department of Information Systems Faculty of Computers and Information, Cairo University Cairo, Egypt February, 2007

23 June June June th ESISACT Conference - Cairo Surveying Workflow Modeling Techniques 2 Outline Introduction Overview of Workflow Systems History of Workflow Technology Categories of Workflow Management Systems Workflow Standards WfMSs vs. Other Applications Workflow Model Concepts Workflow Modeling Techniques Current Work References

23 June June June th ESISACT Conference - Cairo Surveying Workflow Modeling Techniques 3 Introduction Although interest in WF has started some time ago, its importance has been stressed by interest in EIS. The Automation of business processes was the motivation for the foundation of Business Process Management (BPM) and Workflow Management (WfM) applications. WfMSs help business to automate business tasks by routing right information to right people at the right time. The aim of our research is to build a Framework for Evaluating Workflow Modeling Techniques.

23 June June June th ESISACT Conference - Cairo Surveying Workflow Modeling Techniques 4 Overview of Workflow Systems  What is A Workflow? “The automation of a business process, in whole or part, during which documents, information or tasks are passed from participant to another for action, according to a set of procedural rules” (WfMC, 1999).  What is A Workflow Management System? WfMS determines the flow of work according to predefined business process definition. Also, WfMS manages the resources such as applications, data, people required to meet goals and provides monitoring facilities and control capabilities (zur Muehlen and Allen, 2000a).

23 June June June th ESISACT Conference - Cairo Surveying Workflow Modeling Techniques 5 Overview of Workflow Systems Cont. Figure (1) Terms in Workflow Management (adapted from WfMC, 1999)

23 June June June th ESISACT Conference - Cairo Surveying Workflow Modeling Techniques 6 History of Workflow Technology Information System passed through many generations from start until now In the 60’s, Stand-alone Applications In the 70’s, Database Management Systems In the 80’s, User Interface In the 90’s, Workflow Technology Figure (2) WfMSs Foundation (adapted from Aalst, 1998)

23 June June June th ESISACT Conference - Cairo Surveying Workflow Modeling Techniques 7 History of Workflow Technology Cont. Workflow Generations 1 st Generation - Office Procedure Systems Monolithic Applications such as image or document management systems Monolithic Applications such as image or document management systems 2 nd Generation - Image Management Applications Script Language to represent the workflow specifications (Abbot and Sarin, 1994, cited in Veijalainen et al., 1995) 3 rd Generation - Open Workflow Engine Graphical User Interface and is interpreted by the workflow engines (McCarthy and Bluestein, 1991, cited in Du and Elmagarmid, 1997)

23 June June June th ESISACT Conference - Cairo Surveying Workflow Modeling Techniques 8 Categories of Workflow Management Systems Criteria for Workflow Types: Functionality Functionality Deployment or (Integration) Deployment or (Integration) Process Structure Process Structure First, we consider the work of (Kobielus, 1996, cited in DiCterino and Larsen, 1997) for dividing WfMSs according to their Functionality. 1.Production Workflow Systems 2.Messaging-based or (Administrative) Workflow Systems 3.Web-based Workflow Systems 4.Suite-based Workflow Systems

23 June June June th ESISACT Conference - Cairo Surveying Workflow Modeling Techniques 9 Categories of Workflow Management Systems Cont. Second, we consider the work of zur Muehlen and Allen (2000b) for dividing WfMSs according to their Deployment or Integration 1.Autonomous Workflow Systems is functional without any additional application software. Application systems that are external to the WfMS are invoked at runtime. 2.Embedded Workflow Systems is only functional if integrated with ERP Systems. 3.Multi-level Workflow Systems It is considered to be a hybrid workflow system that consists of two types.

23 June June June th ESISACT Conference - Cairo Surveying Workflow Modeling Techniques 10 Categories of Workflow Management Systems Cont. Third, we consider the work of Huth et al. (2001) for dividing WfMSs according to their Process Structure. 1.Structured Workflow Systems The processes are completely predefined, well-structured such as application of consumer credit. 2.Semi-Structured Workflow Systems The processes in semi-structured workflow are highly recurrent, partially predefined such as consumer credit application with particular customer requests. 3.Ad hoc Workflow Systems The processes in ad hoc workflow express the daily business life which requires modifications and can be determined in advance. The processes in ad hoc are characterized by urgent, exceptional, and confidential such as new type of request for customer.

23 June June June th ESISACT Conference - Cairo Surveying Workflow Modeling Techniques 11 Workflow Standards The Workflow Management Coalition (WfMC) founded in August 1993 to promote the use of workflow through the establishment of standards for software terminology, interoperability and connectivity between workflow products. Also, WfMC is a non profit, global organization of developers, consultants, analysts and university research groups engaged in WfMSs and BPMSs; for more details about the WfMC Structure and publications see

23 June June June th ESISACT Conference - Cairo Surveying Workflow Modeling Techniques 12 Workflow Reference Model Cont. The WfMC Reference model focuses on the five interfaces between the workflow enactment service and the tools. Also, for each of these interfaces and some related areas, standards have been produced. Figure (3) The Workflow Reference Model (adapted from Hollingsworth, 1995)

23 June June June th ESISACT Conference - Cairo Surveying Workflow Modeling Techniques 13 WfMSs vs. Other Applications WfMS vs. ERP We exhibit the relationship between WfMS and other systems such as Enterprise Resource Planning (ERP), Groupware Systems or Computer Supported Cooperative Work (CSCW), and Business Process Management Systems (BPMS). WfMS vs. ERP Cardoso et al. (2004) have developed a comparison between WfMS and ERP Systems. WfMSERP Domain Scope  Customized processes  Domain independence  Ad-hoc or dynamic domains  No international settings  Embedded processes  Domain specific  Static domains  International settings Technological Scope  Process- centric  Heterogeneous & autonomous environments  Process & Data-centric  Homogeneous environments with common data infrastructures System Implementation  Manually designed & corresponding code is automatically generated  Based on "off- the-shelf" components Table (1) WfMS vs. ERP (adapted from Cardoso, 2004)

23 June June June th ESISACT Conference - Cairo Surveying Workflow Modeling Techniques 14 WfMSs vs. Other Applications WfMS vs. Groupware WfMS vs. Groupware Systems According to work of Chaffey (1998), we develop a comparison between WfMSs and Groupware systems. WfMSGroupware Focus  Process- Centric  Sharing Information Similarities & Products o Both WfMS and Groupware systems are commonly used for collaboration.. o WfMSs products such as Oracle WF, SAP, COSA, etc. o Groupware products such as Lotus Notes, o Groupware products such as Lotus Notes, Novell Groupwise, and MS Exchange Differences  WfMSs help in managing business processes.  WfMSs assigning tasks to actors automatically.  Monitoring processes & remind agents for their tasks through Worklist.  Groupware provides people with functions of - Communicati on - Collaboration - Coordination “Three Cs”.  Allows group discussion, e- meetings, decision support. Table (2) WfMS vs. Groupware Systems

23 June June June th ESISACT Conference - Cairo Surveying Workflow Modeling Techniques 15 WfMSs vs. Other Applications WfMS vs. BPMS WfMS vs. BPMS According to work of Plesums (2005 ), we develop a comparison between WfMSs and BPMSs. Both WfMS and BPMS products are the same in managing a business processes; but they may be very different internally. The difference in architecture of each product may give advantages for each of them according to the situation. WfMSBPMS Focus  Content that required human judgment/ processing  Computer Transactions Similarities o Both define, test, and use business processes o Both WF and BPM vendors are intending to apply integration between the two products Differences  Optimized for semi- automated processes  It defines & manages business process, but has delay associated with humans.  Optimized for automated processes  It defines & manages overall business process whenever it is enacted Table (3) WfM vs. BPM Systems

23 June June June th ESISACT Conference - Cairo Surveying Workflow Modeling Techniques 16 WfMSs vs. Other Applications Our Perspective Figure (4) WfM vs. Other Applications Structured Groupware BPM WfMS Process Structure ERP Ad-hoc Semi- structured Data-driven Process-driven Focus Centric

23 June June June th ESISACT Conference - Cairo Surveying Workflow Modeling Techniques 17 Workflow Model Concepts According to zur Muehlen (1999), the success of a WfMS stands on the quality of the Wf systems and the quality of Wf models that can be modeled by using these systems. Now, we present common concepts which appear in workflow modeling techniques 1. Case It is a specific instance of the business that workflow handle. e.g. an insurance claim, an order, or a patient in a hospital e.g. an insurance claim, an order, or a patient in a hospital 2. Task It is a logical unit of work. By identifying tasks. Also, a task has different types: manual, automatic, and semi-automatic. e.g. assessing an evaluation report, or filing a complaint 3. Process Process consists of interrelated tasks should be executed. The lifecycle of a case is defined by a process. e.g. handling complaint of customers, or holiday request

23 June June June th ESISACT Conference - Cairo Surveying Workflow Modeling Techniques 18 Workflow Model Concepts Cont. 4. Routing Routing determines in which order tasks need to be performed. There are four basic constructs: A.Sequential B.Parallel C.Selective or choice D.Iteration 5. Allocation Allocation addresses the issue of who will be performing the work during execution of a workflow either Humans or Machines. 6. Enactment The Enactment determines when the resources will actually execute the work that has been allocated to them. Aalst and Hee (2002), and Reijers (2002)

23 June June June th ESISACT Conference - Cairo Surveying Workflow Modeling Techniques 19 Workflow Modeling Techniques Workflow design is focused on finding the structure of workflow processes. Workflow Modeling involves defining of “how” an organization performs its business activities. Workflow Modeling diagrams include detailed information about How each activity is triggered How each activity is triggered What resources are used to complete the activity What resources are used to complete the activity What deliverables are created by the activity What deliverables are created by the activity There are many Workflow Modeling Techniques are used to model business processes such as 1.Petri Nets (PNs). 2.Event-driven Processes Chains (EPCs). 3.UML Activity Diagrams.

23 June June June th ESISACT Conference - Cairo Surveying Workflow Modeling Techniques 20 Petri Nets Petri Nets (PNs) were devised in 1962 by Carl Adam Petri as a Formal tool for modeling and analyzing processes. Also, Petri Nets are called Classical Petri Nets. PNs enable to describe processes graphically. PNs have a strong mathematical basis. A Petri net consists of places and transitions. Arcs either run from place to transition or run from transition to place only. Places may contain tokens indicated using black dots. Tokens represent objects which contain information or parameters move from one state to another. Aalst and Hee (2002)

23 June June June th ESISACT Conference - Cairo Surveying Workflow Modeling Techniques 21 Petri Nets Cont. Transitions are active components (i.e. an Event). The places are passive components (i.e. Location, or Condition). PNs extended in High-level Petri Nets to handle complex business processes. The most important extensions of HPNs are Colour extension, Time extension and Hierarchical extension. The most important extensions of HPNs are Colour extension, Time extension and Hierarchical extension. Aalst (1998), there are several reasons for using (PNs) in modeling workflow such as: [Formal semantics - Graphical nature - Routing constructs - Well-known properties - Analysis techniques - Vendor independent] There are some workflow tools uses PNs such as COSA, INCOME, and LEU.

23 June June June th ESISACT Conference - Cairo Surveying Workflow Modeling Techniques 22 Petri Nets Simple Case Case in Brief Handling Complaints Process aimed to manage (CRM), customer make a complaint for a particular service and determines responsible department. Figure (5) Handling Complaint Process represented by Petri Nets Notations

23 June June June th ESISACT Conference - Cairo Surveying Workflow Modeling Techniques 23 Event-driven Process Chains Event-driven Process Chains (EPCs) were introduced by Keller, Nüttgens and Scheer in 1992 as a Graphical business process description language. EPCs enable to describe processes graphically. EPC consists of Functions, Events, and Logical connectors. Functions are the basic building blocks which need to be executed. Events may correspond to the post-condition of one function and act as a pre-condition of another function. Aalst (1999)

23 June June June th ESISACT Conference - Cairo Surveying Workflow Modeling Techniques 24 Event-driven Process Chains Cont. Logical connectors can be used to connect activities and events. There are three types of logical connectors: (And – OR – XOR) EPCs suffer from the syntax and the semantics are not well defined. EPCs have become a widespread process modeling technique. EPCs are used in many different tools such as SAP R/3, ARIS, LiveModel/ Analyst and Visio Function XOR v ^ Logical Connectors Event

23 June June June th ESISACT Conference - Cairo Surveying Workflow Modeling Techniques 25 Event-driven Process Chains Simple Case Case in Brief Handling Orders Process aimed to manage the Orders of a Customer. Figure (6) Handling Orders Process represented by EPCs Notations

23 June June June th ESISACT Conference - Cairo Surveying Workflow Modeling Techniques 26 UML Activity Diagrams Unified Modeling Language (UML) was introduced by Booch and Rumbough of Rational Software Corporation in 1994 for unifying Object Modeling Techniques (OMT). In 1995, Ivar Jacobson has contributed by his work on Object-Oriented Software Engineering (OOSE) to UML project within Rational. They have decided UML as a standard language for Object-Oriented Modeling. UML 1.3 provides many types of diagrams, each diagram is used for specific purpose such as –Use Case Diagram –Class Diagram –Sequence Diagram –Collaboration Diagram –Statechart Diagram –Activity Diagram (Close to WF Model) –Component Diagram, and –Deployment Diagram Suites

23 June June June th ESISACT Conference - Cairo Surveying Workflow Modeling Techniques 27 UML Activity Diagrams Cont. According to Aalst and Hee (2002) UML Activity diagrams are used for enterprise modeling, WF modeling, and BPR. Activity diagram depends on Swimlanes and Collaboration diagrams for representation of business processes. A swimlane enables for partitioning the process into roles or organizational units. A collaboration diagram focuses on the organizations of objects that participate in an interaction. Activity Diagrams Shapes Branch Activity Control Flow Object Flow

23 June June June th ESISACT Conference - Cairo Surveying Workflow Modeling Techniques 28 UML Activity Diagrams Simple Case Case in Brief Holiday Request Process aimed to manage the request and approval of holidays for employees. Figure (7) Handling Employee Request for a Holiday represented by UML Activity Diagrams Notations

23 June June June th ESISACT Conference - Cairo Surveying Workflow Modeling Techniques 29 Current Work First, Complete the survey of workflow modeling techniques. Second, Present some issues related to workflow model such as Flexibility, Interoperability, etc. Third, Build an Evaluation Framework for workflow modeling techniques. Finally, Applying framework on a real world Case Study.

23 June June June th ESISACT Conference - Cairo Surveying Workflow Modeling Techniques 30 Workflow Modeling Techniques An Evaluation Framework [Initial] (PNS)(EPCs)Activity DiagramOthers Focus/Basis Notations WF Patterns WF Perspectives Process Structure Analysis Tech. End-User Comm. ………. MT FC Table (4) Initial Evaluation Framework for Workflow Modeling Techniques

23 June June June th ESISACT Conference - Cairo Surveying Workflow Modeling Techniques 31 Acknowledgements I wish to express my thankfulness and gratefulness to my Supervisor Dr. Galal Hassan Galal-Edeen for his invaluable guidance, his helpful suggestions and his great continuous efforts. Also, I wish to introduce my thanks for Prof. Dr. Mohamed El Hadi for his supporting Youth Researchers to present their work in ESISACT Conference. Thank you for all Attendees.

23 June June June th ESISACT Conference - Cairo Surveying Workflow Modeling Techniques 32 References Aalst, W.M.P. van der. (1998). "The Application of Petri Nets to Workflow Management", The Journal of Circuits, Systems and Computers, Vol (8), No (1), pp Aalst, W.M.P. van der. (1999). "Formalization and Verification of Event-driven Process Chains", The Journal of Information and Software Technology, Vol (41), No (10), pp Aalst, W.M.P. van der, and Hee, K.M. van. (2002). "Workflow Management: Models, Methods, and Systems", The MIT Press Cambridge, Massachusetts London, England. Avison, D., and Fitzgerald, G. (2003). "Information Systems Development: Methodologies, Techniques, and Tools", 3rd Edition, McGRAW-Hill, London, England. Cardoso, J., Bostrom, R. P., and Sheth, A. (2004). "Workflow Management Systems and ERP Systems: Differences, Commonalities, and Applications", Journal of Information Technology and Management, Vol (5), No (3), pp Chaffey, D. (1998). "Groupware, Workflow and Intranets: Reengineering the Enterprise with Collaborative Software", Butterworth-Heinemann, Newton, MA, USA.

23 June June June th ESISACT Conference - Cairo Surveying Workflow Modeling Techniques 33 References Cont. DiCaterino, A., and Larsen, K. (1997). "An Introduction to Workflow Management Systems", Center for Technology in Government, Albany / SUNY University. Du, W., and Elmagarmid, A. (1997). "Workflow Management: State of the Art vs. State of the Products", In the Proceedings of NATO Advanced Study Institute on Workflow Management Systems, Istanbul, Turkey, HP Laboratories Technical Report, HPL Hollingsworth, D. (1995). "Workflow Management Coalition: The Workflow Reference Model", Workflow Management Coalition (WfMC), TC , Winchester, UK. [Available at [Available at Huth, C., Erdmann, I., and Nastansky, L. (2001). "GroupProcess: Using Process Knowledge from the Participative Design and Practical Operation of Ad Hoc Processes for the Design of Structured Workflows", In the Proceedings of 34th Annual Hawaii International Conference on Systems Science, (CD-ROM), Computer Society Press. Jablonski, S. (1995). "On the Complementarity of Workflow Management and Business Process Modeling", ACM SIGOIS Bulletin, Vol (16), No (1), pp Karagiannis, D. (1995). "BPMS: Business Process Management Systems", ACM SIGOIS Bulletin, Vol (16), No (1), pp

23 June June June th ESISACT Conference - Cairo Surveying Workflow Modeling Techniques 34 References Cont. Mangan, P., and Sadiq, S. (2002). "On Building Workflow Models for Flexible Processes", In the Proceedings of the 13th Australasian Database Conference (ADC), Vol (5), pp , Melbourne, Australia. Oren, E., and Haller, A. (2005). "Formal Frameworks for Workflow Modelling", Digital Enterprise Research Institute (DERI), National University of Ireland, Technical Report, DERI-TR , Galway. Plesums, C. (2005). "Workflow in the World of BPM: Are They the Same?", Workflow Handbook 2005, In Layna Fischer (Ed.), Lighthouse Point, Florida, USA, pp Reijers, H.A. (2002). "Design and Control of Workflow Processes: Business Process Management for the Service Industry", Ph.D. thesis, Eindhoven University of Technology, Eindhoven, Netherlands. Wamelink, J.W.F., Stoffele, M., and Aalst, W.M.P. van der. (2002). "Workflow Management in Construction: Opportunities for the Future", In the Proceedings of Conference of Distributing Knowledge in Building (CIB W78), Vol (78), pp , Aarhus, Denmark. WfMC. (1999). “Workflow Management Coalition Terminology & Glossary”, WfMC- TC-1011, Issue (3.0) Draft, Winchester, UK. [Available at [Available at

23 June June June th ESISACT Conference - Cairo Surveying Workflow Modeling Techniques 35 References Cont. Veijalainen, J., Lehtola, A., and Pihlajamaa, O. (1995). "Research Issues in Workflow Systems", In the 8th ERCIM Database Research Group Workshop on Database Issues and Infrastructure in Cooperative Information System, Norway. zur Muehlen, M. (1999). "Evaluation of Workflow Management Systems Using Meta Models", In the Proceedings of the 32nd Hawaii International Conference on System Sciences (HICSS), Wailea, HI. zur Muehlen, M., and Allen, R. (2000a). "Embedded vs. Autonomous Workflow - Putting Paradigms into Perspective", Excellence in Practice, Vol (IV), In Layna Fischer (Ed.), Lighthouse Point, Florida, pp zur Muehlen, M., and Allen, R. (2000b). "Workflow Management Coalition Classification: Embedded and Autonomous Workflow Management Systems", Workflow Management Coalition (WfMC), Lighthouse Point, Florida. [Available at [Available at EndNote for This Paper EndNote for This Paper

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