1. © Eric Yu 2001 1 Strategic Actor Relationships Modelling with i* Eric Yu University of Toronto December 13-14, 2001 IRST, Trento, Italy

2. © Eric Yu 2001 2 Agenda Session 1 – Introduction December 13, 14:30-16:30 Background and Motivations Basic concepts –The Strategic Dependency Model –The Strategic Rationale Model More Examples –Software process modelling –Software architecture –Business redesign Homework

3. © Eric Yu 2001 3 Agenda Session 2 – Workshop December 14, 14:30-16:30 Example –Intellectual Property Management Discussions of Exercises References –http://www.cs.toronto.edu/km/istarhttp://www.cs.toronto.edu/km/istar –http://www.cs.toronto.edu/km/OMEhttp://www.cs.toronto.edu/km/OME –http://www.fis.utoronto.ca/~yu

4. © Eric Yu 2001 4 Agent-Oriented Software Engineering: A Requirements Engineering Perspective Eric Yu University of Toronto September 2001 IRST Seminar

5. © Eric Yu 2001 5 Agent-Oriented Software Situated  sense the environment and perform actions that change the environment Autonomous  have control over their own actions and internal states  can act without direct intervention from humans Flexible  responsive to changes in environment, goal-oriented, opportunistic, take initiatives Social  interact with other artificial agents and humans to complete their tasks and help others Jennings, Sycara, Wooldridge (1998) A Roadmap of Agent Research & Development. Autonomous Agents & Multi-Agent Systems journal.

6. © Eric Yu 2001 6 But why Agent Orientation? The “world” (application environment) has become more distributed, autonomous, networked…  I.e. the agent properties are being found in the world.  E.g. E-commerce, e-health, e-learning, groupwork, kn mgt Question is: how to make the software systems meet these desired properties (in the world) That’s the job of RE (and SE).  But previously, no way of expressing these properties.  RE languages need to be social, intentional.  Most AOSE methodologies focus the system, not on relationship to the world

7. © Eric Yu 2001 7 Requirements Engineering relationship between system and environment.  Bubenko (1980), Greenspan (1982), Jackson (1983)… Traditional focus:  consistency, completeness, …  e.g., “Three Dimensions of RE” Pohl (1993) informal -> formal (representation) opaque -> complete (specification) personal view -> common view (agreement)  Suitable for a more stable, non-distributed world Recent:  goals, scenarios, agents  See overview in van Lamsweerde (ICSE 2000)

8. © Eric Yu 2001 8 Ontologies for Modelling Static Ontologies Dynamic Ontologies Intentional OntologiesIntentional Ontologies Social OntologiesSocial Ontologies [J. Mylopoulos CAiSE 97 Keynote] Most current conceptions and models of information systems are based on static and dynamic ontologies. business process models workflow models enterprise models … UML

9. © Eric Yu 2001 9 A typical process model … but we need deeper understanding! Automobile insurance claims example

10. © Eric Yu 2001 10 … a deeper understanding about processes Car owner wants car to be repaired Insurance company wants to minimize claims payout Car owner wants fair appraisal of repairs Insurance agent wants to maintain good customer relations

11. © Eric Yu 2001 11 Modelling Strategic Actor Relationships and Rationales - the i* modelling framework –have goals, beliefs, abilities, commitments –depend on each other for goals to be achieved, tasks to be performed, resources to be furnished –are semi-autonomous -- not fully knowable / controllable

12. © Eric Yu 2001 12 Strategic Dependency Relationship Actor A I want … Actor B I can … DD Car Be Repaired

13. © Eric Yu 2001 13 i* objectives, premises, key concepts Actors are semi-autonomous, partially knowable Strategic actors, intentional dependencies have choice, reasons about alternate means to ends means-ends alternatives DD wants and abilities

14. © Eric Yu 2001 14 i* modeling 1.explicit intentionality  goals 2. implicit intentionality  agents functional decomposition means-ends alternatives wants and abilities inputs outputs DD

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20. © Eric Yu 2001 20 Development-World model refers to and reasons about… Operational-World models Alt-1 Alt-2 To-be As-is Strategic Rationale Model Strategic Dependency Models

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24. © Eric Yu 2001 24 Softgoal Operationalizations: Contribution Relationship Side-effects to softgoals: Correlation Relationship

25. © Eric Yu 2001 25 Analysis and Design Support opportunities and vulnerabilities –ability, workability, viability, believability –insurance, assurance, enforceability –node and loop analysis design issues –raising, evaluating, justifying, settling –based on qualitative reasoning [Chung Nixon Yu Mylopoulos (2000) Non-Functional Requirements in Software Engineering. Kluwer Academic Publishers.]

26. © Eric Yu 2001 26 Sample i* representation for an actor (in Telos) TELL Class Physician IN PositionClass ISA ProfessionalPosition WITH resDepends, committedTo fs: FeeForTreatment WITH dependee cm:ClaimsManager end goalDepended, commitsTo td: $Treated(p.injury)$ WITH depender p:Patient end taskDepends, committedTo tm: TakeMedication(p.med) WITH dependee p:Patient end covers tp: TreatingPatient(p) bi: Billing(p.insurCo) integrityConstraint correctClaimsManager: $cm=p.insurCo.claimsMgr$ end

27. © Eric Yu 2001 27 The Strategic Rationale Model - a partial schema

28. © Eric Yu 2001 28 Another Example: Meeting Scheduler From: E. Yu. Towards Modelling and Reasoning Support for Early- Phase Requirements Engineering 3rd IEEE Int. Symp. on Requirements Engineering (RE'97) Jan. 6- 8, 1997, Washington D.C., USA. pp. 226-235.

29. © Eric Yu 2001 29 “Strategic Dependency” Model Meeting Scheduling Example [Yu RE97]

30. © Eric Yu 2001 30 Revealing goals, finding alternatives Ask “Why”, “How”, “How else”

31. © Eric Yu 2001 31 Scheduling meeting …with meeting scheduler

32. © Eric Yu 2001 32 “Strategic Rationale” Model with Meeting Scheduler SR2