social structures in tropos manuel kolppaolo giorginijohn mylopoulos u louvain u trento u toronto u...

Social StructuresSocial Structures in Tropos in Tropos

Manuel KolpManuel Kolp Paolo GiorginiPaolo Giorgini John MylopoulosJohn Mylopoulos

U Louvain U TrentoU Louvain U Trento U Toronto U Toronto

First First TTropos Workshopropos Workshop, , Trento, 15-16 November 2001Trento, 15-16 November 2001

http://www.cs.toronto.edu/km/troposhttp://www.cs.toronto.edu/km/tropos

Social Structures in Tropos 2

MotivationMotivation

Narrowing the gapNarrowing the gap betweenbetween requirementsrequirements modeling and modeling and systemsystem

designdesign

Same concepts for Same concepts for bothboth phases: phases: Social and intentional structuresSocial and intentional structures

Coordinated & autonomous withCoordinated & autonomous with goalsgoals & social & social dependenciesdependencies

ConceptsConcepts fromfrom organizationorganization theory, …theory, … andand early requirements early requirements

modelingmodeling

OntologyOntology: : 3 levels3 levels (Macro, micro, atomic) (Macro, micro, atomic)


Social OntologySocial Ontology

3 Levels3 Levels

11 MacrolevelMacrolevel : : OrganizationalOrganizational Styles (Organization Theory) Styles (Organization Theory)

– Vertical Integration, Pyramid, Joint Venture, Structure in 5, Bidding, Vertical Integration, Pyramid, Joint Venture, Structure in 5, Bidding,

Hierarchical Contracting, Co-optation, TakeoverHierarchical Contracting, Co-optation, Takeover

22 Micro levelMicro level : : Social PatternsSocial Patterns ( (Agent, COOPISAgent, COOPIS Community) Community)

– Broker, Matchmaker, Contract-Net, Mediator, Monitor, Embassy, Broker, Matchmaker, Contract-Net, Mediator, Monitor, Embassy,

Wrapper, Master-Slave, ...Wrapper, Master-Slave, ...

33 Atomic Atomic : : Social and intentional conceptsSocial and intentional concepts – – i*i*

– goals, actors, social dependencies, …goals, actors, social dependencies, …


Organization TheoryOrganization Theory

MintzbergMintzberg, , Scott, Galbraith, …Scott, Galbraith, …

Studies alternatives andStudies alternatives and modelsmodels for (business) organizationsfor (business) organizations

Model theModel the coordinationcoordination of business stakeholders -- individuals, of business stakeholders -- individuals, physical or social systems -- to achieve common (business)physical or social systems -- to achieve common (business) goalsgoals. .


Structure in 5Structure in 5

Operational coreOperational core :: basic operationsbasic operations -- the input, processing, -- the input, processing, output associated with running the organization.output associated with running the organization.

StrategicStrategic apexapex : : executiveexecutive,, strategicstrategic decisions. decisions.

SupportSupport : : AssistsAssists the operation core for non-operational services the operation core for non-operational services outside the basic flow of operational procedures. outside the basic flow of operational procedures.

TechnostructureTechnostructure : : standardizesstandardizes the behavior of other the behavior of other components, help the system components, help the system adaptadapt to its environment. to its environment.

Middle lineMiddle line : Actors who : Actors who joinjoin the apex to the core. the apex to the core.


Structure in 5 Structure in 5 and Joint Ventureand Joint Venture


Bidding and Vertical IntegrationBidding and Vertical Integration


Structure in 5 inStructure in 5 in detail (from Mintzberg) detail (from Mintzberg)


Formal AnalysisFormal Analysis

DependencyDependency StrategicManagement StrategicManagementTypeType SoftGoal SoftGoalModeMode achieve achieveDependerDepender MiddleAgncy MiddleAgncyDepDepeendeendee Apex Apex AttributeAttribute constant objective : MiddleAgencyObjective constant objective : MiddleAgencyObjectiveCreationCreation

conditioncondition objective.strategyobjective.strategytriggertrigger Pursue(objective)Pursue(objective)

FulfillmentFulfillmentconditioncondition for depender for depender

ma-strategy: MiddleAgencyStrategy ma-strategy: MiddleAgencyStrategy (( org -strategy: OrgStrategy org -strategy: OrgStrategy

(objective.strategy=strategy ^ (objective.strategy=strategy ^ consistent(ma-strategy,org-strategy))consistent(ma-strategy,org-strategy))

[the StrategicManagement dependency is created when there is no strategy for a [the StrategicManagement dependency is created when there is no strategy for a given middle agency objective, and it is fulfilled when there exists a middle agency given middle agency objective, and it is fulfilled when there exists a middle agency strategy consistent with all the strategies of the organization]strategy consistent with all the strategies of the organization]


The Mobile Robot Case StudyThe Mobile Robot Case Study

MMobile robotobile robot activities: activities:- - AAcquiringcquiring the input the input from from sensors, sensors,

- - CControllingontrolling the motion of moveable part the motion of moveable partss, ,

- - PPlanninglanning its future path. its future path.

External External FFactorsactors::- O- Obstacles may bstacles may blockblock the path, the path,

- S- Sensor inputs may be ensor inputs may be imperfectimperfect, ,

- T- The robot may run out of he robot may run out of powerpower, ,

- M- Mechanical limitations may restrict echanical limitations may restrict accuracyaccuracy

- T- The robot may manipulate he robot may manipulate hazardoushazardous materials, materials,

- - UUnpredictablenpredictable events may leave little time for responding. events may leave little time for responding.


Conventional ArchitecturesConventional Architectures

Task TreesTask Trees : : HHierarchiesierarchies of tasks. Parent tasks of tasks. Parent tasks initiate child tasks. initiate child tasks. TemporalTemporal dependencies dependencies between tasksbetween tasks permit selective concurrency. permit selective concurrency.

LayersLayers

Control LoopControl Loop


Organizational ArchitecturesOrganizational Architectures: Structure-in-5: Structure-in-5


Quality Attributes for Mobile RobotsQuality Attributes for Mobile Robots

CoordinativityCoordinativity. A mobile robot has to coordinate the actions it . A mobile robot has to coordinate the actions it undertakes to achieve its undertakes to achieve its objectiveobjective with the reactions forced on it by the with the reactions forced on it by the environmentenvironment..

PredictabilityPredictability. . For a mobile robot, never will all the circumstances of For a mobile robot, never will all the circumstances of the operation be fully the operation be fully predictablepredictable. The architecture must provide the . The architecture must provide the framework in which the robot can act even when faced with framework in which the robot can act even when faced with incompleteincomplete information.information.

Failability-ToleranceFailability-Tolerance. . MMust prevent the failure of the robot’s operation ust prevent the failure of the robot’s operation and its environment. and its environment. LocalLocal problems like reduced power supply, problems like reduced power supply, unexpectedly opening doors should not necessarily imply the unexpectedly opening doors should not necessarily imply the failurefailure of of the the missionmission..

AdaptabilityAdaptability.. Application for mobile robots frequently requires Application for mobile robots frequently requires experimentation and experimentation and reconfigurationreconfiguration. . CChangehangess in in assignmentsassignments require require regular modification.regular modification.


Strengths and Weaknesses of Robot ArchitecturesStrengths and Weaknesses of Robot Architectures

LoopLoop LayersLayers Task TreeTask Tree S-in-5S-in-5 Joint-Vent.Joint-Vent.

CoordinativityCoordinativity -- -- ++ -- ++ ++ ++ ++

PredictabilityPredictability ++ -- ++ ++ -- ++ ++ ++

Failability-Tol.Failability-Tol. ++ ++ -- ++ ++ ++

AdaptabilityAdaptability ++ -- ++ -- ++ ++ ++ --


CoordinativityCoordinativity

Control loop:Control loop: SimplicitySimplicity is a drawback when dealing with is a drawback when dealing with complexcomplex tasks, tasks, no leverage for decomposing the software into more precise components. no leverage for decomposing the software into more precise components.

Layers:Layers: services and requests between services and requests between adjacentadjacent layers. Transactions not layers. Transactions not always straight-forward. Need to always straight-forward. Need to skipskip layers to coordinate behavior. layers to coordinate behavior.

Task trees:Task trees: clear clear separationseparation of action and reaction. Allows incorporation of of action and reaction. Allows incorporation of concurrent agents. Components have concurrent agents. Components have little interactionlittle interaction with each other. with each other.

Structure-in-5:Structure-in-5: separates separates datadata (sensor control, interpreted results, world (sensor control, interpreted results, world model) from model) from controlcontrol (motor, navigation, scheduling, planning and user- (motor, navigation, scheduling, planning and user-level) level) hierarchieshierarchies

Joint venture:Joint venture: Components Components interactinteract via the via the joint managerjoint manager for strategic for strategic decisions. They indicate their interest, the joint manager returns them decisions. They indicate their interest, the joint manager returns them such information or mediates the request to other partner component. such information or mediates the request to other partner component.


NFRNFR Analysis: Selecting Architectures Analysis: Selecting Architectures


Mobile Robot Mobile Robot Organizational EnvironmentOrganizational Environment

With the Bidding StyleWith the Bidding Style

0. task auctionned

Issuer Auctioneer

Bidder

Bidder

Bidder


Using These SocialUsing These Social Structures at Structures at AllAll Steps Steps

Early requirementsEarly requirements (organization modeling): (organization modeling): stakeholdersstakeholders

(people, organizations, systems), (people, organizations, systems), goalsgoals and and dependenciesdependencies..

Late requirementsLate requirements, the system-to-be as , the system-to-be as one or a few social one or a few social

actorsactors (blackbox) participating in the organization model. (blackbox) participating in the organization model.

Architectural designArchitectural design, the system as an , the system as an organizationorganization of actors of actors

Detailed designDetailed design, system actors transformed into agents by , system actors transformed into agents by

means of means of social patternssocial patterns

Implementation: Implementation: Multi-agent systemMulti-agent system as as societiessocieties of of

individuals individuals to achieve particular, possible common to achieve particular, possible common goalsgoals..


Media Industry: Media Industry: Early RequirementsEarly Requirements

Organization Modeling Organization Modeling with the Joint Venture with the Joint Venture StyleStyle


Media Industry: Media Industry: Late RequirementsLate Requirements

With the Vertical With the Vertical Integration StyleIntegration StyleWith the With the

Bidding StyleBidding Style


Media Industry: Media Industry: ArchitecturArchitectural Designal Design

E-business styles: E-business styles: on web, protocols, on web, protocols, technologiestechnologies

Not on business Not on business processes, NFRsprocesses, NFRs

No organization of No organization of the architecture, the architecture, conceptual high-level conceptual high-level perspectiveperspective


Social PatternsSocial Patterns

EmbassyEmbassy

MediatorMediator

Contract-NetContract-Net


Detailed Design with Social PatternsDetailed Design with Social Patterns


ConclusionConclusion

System described with concepts from requirements and System described with concepts from requirements and organization modelingorganization modeling

Narrows the gap requirements / designNarrows the gap requirements / design

Multi-Agent Architectures asMulti-Agent Architectures as social and intentional structuressocial and intentional structures

Best suited to open, dynamic and distributed applicationsBest suited to open, dynamic and distributed applications

Ontology on 3 levelsOntology on 3 levels::

– MacroMacro: : Organization StylesOrganization Styles

– MicroMicro: : Social PatternsSocial Patterns

– AtomicAtomic: : i* i* - - goals, actors, social dependencies, …goals, actors, social dependencies, …


Discussion: Problems, Suggestions Discussion: Problems, Suggestions ??????

Organization Theory Organization Theory why notwhy not Sociology, Group Dynamics, … Sociology, Group Dynamics, …

Formalization at the metalevel: Makes sense, not too abstract??Formalization at the metalevel: Makes sense, not too abstract??

Formal result: ex.: sound and complete, instantiation ethicsFormal result: ex.: sound and complete, instantiation ethics

Convincing real-world size case study: Organization Modeling, Convincing real-world size case study: Organization Modeling, Early (Business) RequirementsEarly (Business) Requirements

Styles vs Patterns Macro level <-> MicrolevelStyles vs Patterns Macro level <-> Microlevel

Convincing for organization theorists, sociologists, ontologists??Convincing for organization theorists, sociologists, ontologists??

NFR evaluation: intuitive vs formal for Requirements/ArchitecturesNFR evaluation: intuitive vs formal for Requirements/Architectures

WRT Conventional Architectures: pros & cons, reevaluationWRT Conventional Architectures: pros & cons, reevaluation

Methodology: Social Structures at all steps makes sense?Methodology: Social Structures at all steps makes sense?

social structures in tropos manuel kolppaolo giorginijohn mylopoulos u louvain u trento u toronto u...

Documents

social structures

social systems

social patterns agent

orgstrategy objective

depender mastrategy

mobile robotscoordinativity

given middle agency

organization theorymintzberg