1. Department of Computer Science and Engineering Southern Methodist University 03/17/081 LiGuo Huang lghuang@engr.smu.edu Department of Computer Science & Engineering Southern Methodist University Modeling Value-Based Process with Object Petri-Nets

2. Department of Computer Science and Engineering Southern Methodist University 03/17/082 Value-Based Software Quality Achievement (VBSQA) Process

3. Department of Computer Science and Engineering Southern Methodist University 03/17/083 Neusoft DIMS Upgrade Project Document and Image Management System (DIMS) upgrade from version 6.0 to 7.0 Change of database schema –add, remove or update DB attributes Change of database platforms –new capability of data migration

4. Department of Computer Science and Engineering Southern Methodist University 03/17/084 Initial Experiment of VBSQA Process Application Objective: Tailor VBSQA process framework to ERP software development in China Two week tutorials on VBSQA Process and WinWin Spiral Model –Developed a process instance composed of 22 ERP software development activities  6 misplaced activities due to misinterpretation  4 missing activities

5. Department of Computer Science and Engineering Southern Methodist University 03/17/085 Experience of Initial VBSQA Process Application Feedback from project managers of ERP solution providers –Shorten the new process learning curve –Maintain the flexibility of the process –Identify the flaws in a process instance –Tradeoffs among conflicting software Q-attributes –Determine stakeholders’ perspectives and interaction points

6. Department of Computer Science and Engineering Southern Methodist University 03/17/086 Model VBSQA Process Using Object Petri Nets (OPN) Inherit the merits of Petri Nets (PN) –Formal semantics despite the graphical nature –State-based instead of event-based –Abundance of analysis techniques –Model concurrent process activities Support separation of concerns among various stakeholders’ perspectives –Object-oriented approach –Model VBSQA Process Framework as the System Net (SN) –Model each stakeholder’s process instance in a separate Object Net (ON)  Process activities in ONs are inherited from process steps/milestones in SN –Interaction/negotiation among stakeholders and the SN/ON synchronization can be defined, analyzed, and integrated concurrently

7. Department of Computer Science and Engineering Southern Methodist University 03/17/087 Value-Based Process and OPN

8. Department of Computer Science and Engineering Southern Methodist University 03/17/088 Formal Definitions of VBSQA-OPN An OPN is a 3-tuple –System Net: is a Petri Net with its tokens referring to Object Nets –Object Nets: (n>1) –SN and ON s synchronize via “channels” ρ VBSQA-OPN = –System Net:, VBSQA Process Framework or its tailoring –Object Nets: (n>1) represents a set of process instances of stakeholders, –Synchronization relation between SN and ON s :, a mapping between VBSQA process framework steps/milestones and ERP software development activities. –Guard functions: activation condition(s) of transitions –Constraint 1: Inheritance of chronological order –Constraint 2: Critical Path Dependency

9. Department of Computer Science and Engineering Southern Methodist University 03/17/089 OPN Notations ElementsDescriptionSoftware Process Modeling Place: current state (the marking) of a system; places contain tokens Token: pre- or post- condition of firing a transition Place: current state (the marking) of the System Net (VBSQA process framework) or an object net (a stakeholder’s process instance) Token: 1) pre- or post- condition of activating a process step/milestone in System Net (SN) or an activity in Object Net (ON); 2) refer to an object net Transition: events or actions which cause the change of system state System Net: steps and milestones of VBSQA process framework or its tailoring Object Net: activities of ERP software development Arc: connects a place with a transition or a transition with a place

10. Department of Computer Science and Engineering Southern Methodist University 03/17/0810 VBSQA-OPN System Net – VBSQA Process Framework

11. Department of Computer Science and Engineering Southern Methodist University 03/17/0811 Developer’s Object Net System Acquirer’s Object Net VBSQA-OPN Object Nets – Stakeholders ’ Process Instances

12. Department of Computer Science and Engineering Southern Methodist University 03/17/0812 VBSQA Process Generator – Based on VBSQA-OPN Model

13. Department of Computer Science and Engineering Southern Methodist University 03/17/0813 VBSQA Process Creator – Map ERP Software Development Activities into VBSQA Process Framework VBSQA Process Framework Steps/Milestones (System Net) ERP Software Development Activities (Object Nets) Project cost/benefit analysisEstimate system upgrade cost & develop DMR results chain (Developer) Verify system upgrade cost (System Acquirer) SCS define acceptable & desired values for Q-attributes Requirement elicitation meeting Groupware WinWin negotiation LCA ReviewSelected architecture internal review (Developer) Selected architecture external review CCDInternal core capability demo (Developer) Onsite core capability demo Objectives: To shorten the VBSQA process learning curve To reduce the flaws in generated process instances To adapt to the changes in ERP software development activities and/or workflows

14. Department of Computer Science and Engineering Southern Methodist University 03/17/0814 VBSQA Process Creator – Creating an ERP VBSQA Process Instance

15. Department of Computer Science and Engineering Southern Methodist University 03/17/0815 VBSQA Process Checker – Identifying the Flaws in a VBSQA Process Instance Maintain the flexibility of the process –Allow to remove a step in SN (VBSQA process framework)  Violate critical path activity dependencies due to missing activities VBSQA Process Checker –Formal properties defined in VBSQA-OPN System Net (SN) and implemented in the VBSQA Process Checker Examples of the activity dependency constraints in the SN –SCS define acceptable & desired values for Q-attributes must be completed before Risk analysis & architecture/technology evaluation –Risk analysis & architecture/technology evaluation must be completed before System top-level design –System top-level design must be completed before LCO Review

16. Department of Computer Science and Engineering Southern Methodist University 03/17/0816 VBSQA Process Simulator ROI of Synchronous Stakeholder Interaction Activities –ROI = (Value – Cost)/Cost –Value: V: the total value of the project; E ij (0-1): the effectiveness of a specific process activity on mitigating the risk of Q-attribute i if it is performed in phase j; R i (0-1): the risk of Q-attribute i to the total value of the project. –Cost = Activity Cost + Rework Cost Various combinations of synchronous stakeholder interaction activities and developer internal activities

17. Department of Computer Science and Engineering Southern Methodist University 03/17/0817 VBSQA Process Simulator – ROI of Synchronous Stakeholder Interaction Activities DIMS Top-Priority Q-attributes: Performance, Evolvability

18. Department of Computer Science and Engineering Southern Methodist University 03/17/0818 VBSQA Process Simulator – ROI of Synchronous Stakeholder Interaction Activities

19. Department of Computer Science and Engineering Southern Methodist University Value/Petri Process Costs and Benefits

20. Department of Computer Science and Engineering Southern Methodist University 03/17/0820 Discussion

21. Department of Computer Science and Engineering Southern Methodist University Process V&V Enforce the chronological order of process steps and milestones Identify the violation of critical path activity dependency 03/17/0821

22. Department of Computer Science and Engineering Southern Methodist University Ambiguity Tolerance Process framework: steps, milestones and their order – Process checker: defect identification Pre and post conditions – Process simulation 03/17/0822

23. Department of Computer Science and Engineering Southern Methodist University Scalability Number of process steps: 12 Number of stakeholders/process instances: 4 Model cross-organizational processes 03/17/0823

24. Department of Computer Science and Engineering Southern Methodist University Extensibility Need expertise on Petri-Nets in modeling new capabilities 03/17/0824

25. Department of Computer Science and Engineering Southern Methodist University Flexibility Separation of concerns of different stakeholders/parties on the process Can add activities for individual process instance Support coordination among process instances 03/17/0825

26. Department of Computer Science and Engineering Southern Methodist University Coverage Process simulator –estimate project schedule –estimate project budget –analyze quality attribute tradeoffs –optimize the project plan in terms of ROI –possible future extension: generate templates for deliverables Model multi-views of processes Model cross-organizational processes 03/17/0826

27. Department of Computer Science and Engineering Southern Methodist University Dynamism Defect introduction and removal 03/17/0827