Let's Go All the Way: From Requirements via Colored Workflow Nets to a BPEL Implementation of a New Bank System Wil M. P. van der Aalst Jens Bæk Jørgensen Kristian Bisgaard Lassen

© Kristian Bisgaard Lassen, CoopIS 2005 Bankdata Make software for banks (15 banks and 300 employees) –They provide daily operation of their systems Bankdata in transition from data oriented to process oriented systems design Case: Blanc loan application work process

© Kristian Bisgaard Lassen, CoopIS 2005 Approach ”Bridging the Gap” T0: Manual, Executable Use Case, by Bankdata + authors T1: Manual, by the authors T2: Semi-automatic, by the authors real world (a bank) T0T2 () requirements model textual description Requirements CPNRCPN animation AP system BPEL T1 Colored Workflow Net workflow model (CWN) ()focus on contextprocesses and organization (focus on realizationsystem and software )

© Kristian Bisgaard Lassen, CoopIS 2005 Requirements Model Consists of –Textual description –Requirements CPN –Animation Animation used for prototyping the future workflow Describes the system in its environment and includes –Actions that will remain manual –Actions to be supported by the system –Actions fully automated by the system

© Kristian Bisgaard Lassen, CoopIS 2005 Executable Use Case Requirements CPN Word document Informal flow diag.

© Kristian Bisgaard Lassen, CoopIS 2005 Snapshot of the Animation Customer Advisers Manager Animation interface Loan requests Example animation : Recommendation

© Kristian Bisgaard Lassen, CoopIS 2005 Requirements CPN

© Kristian Bisgaard Lassen, CoopIS 2005 Workflow Model Model of the system Contains only actions to be supported by the system Support the three workflow perspectives Modeling language: Colored Workflow Nets Task (Process definition) Case Resource Work item Activity

© Kristian Bisgaard Lassen, CoopIS 2005 Places Colored Workflow Nets (CWN) Introduction Restriction on Colored Petri Nets Conceptual workflow language Example: Place Types Transition Guard Code segment Arc expressions Markings Arcs

© Kristian Bisgaard Lassen, CoopIS 2005 Colored Workflow Nets Overview Only three kinds of places: –Case : (id,attributes) –Resource : (id,roles,organizational units) –CaseXResource : (case,resource) A CWN without resources places should correspond to a Sound Workflow Net

© Kristian Bisgaard Lassen, CoopIS 2005 Colored Workflow Nets Guidelines Naming convention for variables –c, c1, c2, r, r1, r2, (c,r), (c1,r1), (c2,r2) Arc expressions should only be guiding; e.g. on the form –c, c1, c2, c3 –r, r1, r2, r3 –(c,r), (c1,r1), (c2,r2), (c3,r3) Use only predefined functions –has_role, has_org_unit, etc Only change cases in code segments

© Kristian Bisgaard Lassen, CoopIS 2005 Requirements model vs. Workflow model Requirements modelWorkflow model Describe the system in its environment Describe the workflow system Actions: 1. Manual 2. Supported by the system 3. Automated by the system Actions: 1.Supported by the system 2.Automated by the system No restrictions on expression, uses concepts with no counterpart in the system Restricted vocabulary; e.g., case, resource, various modeling guidelines etc. Focus is on context; process and organization Focus is on realization; system and software

© Kristian Bisgaard Lassen, CoopIS 2005 Colored Workflow Net

© Kristian Bisgaard Lassen, CoopIS 2005 T2’ Workflow net AP system A BPEL skeleton specification –No WSDL specification Meant as template code –Not executable –Should be intuitive for the BPEL programmer Translation to the AP system T2 AP system BPEL Colored Workflow Net workflow model (CWN) T2’’

© Kristian Bisgaard Lassen, CoopIS 2005 While component … (links) Example of the translation: WFN to BPEL Flow component <invoke name=“t 2 ”/> <while condition=“expr3 and not expr4”> <invoke name=“t 5 ”/> </while> <invoke name=“t 7 ”/> Switch component t c2 t c1

© Kristian Bisgaard Lassen, CoopIS 2005 BPEL skeleton

© Kristian Bisgaard Lassen, CoopIS 2005 Conclusion & Future Work Introduced a new bridge from the real world to a running system Colored Workflow Nets needs further work –Theoretical –Tool support (CPN Tools) –Visualization of CWN Prototype new workflow systems on the fly

Questions?

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