Modelling and Analysis of CSCW systems: An Ontology-driven Engineering Approach

Thesis defense Modelling and Analysis of CSCW systems:An Ontology-driven Engineering Approach Supervisors: Dr. José Luis Garrido Bullejos Dra. María V. Hurtado Torres Candidate:Manuel Noguera García Departamento de Lenguajes y Sistemas InformáticosUniversidad de Granada

Outline • Introduction • Motivation • Goals • Foundations • Intended Approach • AMENITIES • Ontology-driven modelling and analysis of CSCW systems • Ontology implementation techniques • Modular design scheme to ontology development • Ontology-based reasoning • Applications of the proposal • Conclusions & Future Work

Motivation • Increment in the complexity of the tasksto be carried out with computing systems  • Involvement of several people/organizations in their accomplishment • Incorporate collaboration capabilities in the system used • Computer-supported Cooperative Work (CSCW) systems: • Intended to help people work efficiently • Strongly influenced by social (human) aspects • Require (as much as possible) complete, clearly-defined, easy-to-manage system models that • cover both structure and behavior • offer general/abstract views of the system to discuss with collaborating stakeholders • A great deal of effort in specification CSCW

Motivation • Models usually focus on selected particular aspects • Several models are needed for the whole system • Scattering of information & design decisions • Unnoticed inconsistencies between models • Semantics is often unclear or too informal • Misunderstandings • Reduce potential of knowledge shared • Difficult communication, coordination, and thus, collaboration between partners CSCW

Goals of the thesis • General goal • Specify collaborative systems through models that: • Capture both structure and behavior • Can be obtained in a systematic manner • Have a clearly-defined semantics • Allow consistency checks to be carried out • Provide a cohesive representation of the system • Secondary goals • Provide a set of techniques to systematically represent common conceptual modelling constructs • Apply the proposed methods to different domains • Develop a tool that assists analysts in the description of CSCW system models

Foundations Model-driven Engineering (MDE) approaches as new paradigms to System and Software Engineering: • Extensive use of models to system development • Aim: Raise the abstraction level of models • Foster discussion with stakeholders • Separate business logic from implementation issues • Enable the implementation of a business logic across different technological platforms  Computation and Technology Independent Models • Adopt UML as the reference modelling notation • Benefit: User-friendly, intuitive models • Drawback: • Lack formal and complete model theoretic semantics to carry out automated reasoning and validation • Spread of information and design decisions across different models (UML  13 different diagrams for system architecture) MDE

Foundations Ontology: • Originally a branch of Metaphysics (or Philosophy) • Specialized meaning in Computer Science: • Formal specifications about a domain  It is possible to talk of an ontology or several ontologies • An ontology = classes (a.k.a. concepts) + relationships (a.k.a. properties and slots) + restrictions on these relationships (a.k.a. facets) • Benefit: • Enable logic-based automated reasoning and consistency checks on the models • Drawback: • Lack user-friendly notation  not suitable to discussion with stakeholders • Focus on the structure of concepts rather than the processes to describe a domain  absence native support to describe behaviour Ontologies

Intended Approach • Ontology Driven Engineering (ODE) • Combined approach of MDE and formal ontologies • Models are formally captured in underlying ontologies • Take advantage of the benefits of both technologies: • High-abstraction level and user-friendly models to discuss with stakeholders • Formal specifications about a domain to carry out consistency checks and infer implicit knowledge • Approach: Devise and apply an ODE process to the modelling and analysis of CSCW systems may help improve their specification process MDE MDE Ontologies Ontologies ODE CSCW + = for

Starting point: AMENITIES [Garrido 2005] Requirement Models • “A MEthodology for aNalysing and desIgning collaboraTIve systEmS” • Core of the methodology: Cooperative Model (COMO) Applied Ethnography UML Use Case Functional Requirements Requirements Model Additional Requirements Cooperative Model (COMO-UML) Cooperative Model (COMO-UML) Organizational View (Organization, Roles,…) Interaction View (Protocols, Artefacts,…) Revise Cognitive View (Tasks, Actions,…) Information View (Documents, Messages,…) Revise UML Diagrams UML Statecharts Analyse Develop Refine Software Development Models (UML) Formal Model (Coloured Petri Nets)

Starting point: AMENITIES [Garrido 2005] • Conceptual framework • Domain vocabulary • Main entities in a collaborative system • Described using natural language and UML

Starting point: AMENITIES [Garrido 2005] • Views of the system Task diagrams Organization diagrams Role diagrams • Make use of and extend UML  lack a formal semantics to carry out automated consistency checks or reasoning • Approach: Representation in an ontology language

Ontology Implementation • First step: Language election • Candidates languages: KIF, LOOM, RDF, OWL... • Choice: OWL-DL(Web Ontology Language – Description Logics) • W3C standard • Machine-processable descriptions that foster interoperability between software agents • Plenty of related technologies • Reasoning capabilities based on Description Logics

Ontology Implementation • Next step: Representation of the AMENITIES conceptual framework in OWL • Process: • define classes in the ontology • arrange the classes in a taxonomic (subclass–superclass) hierarchy • define relationships • describe allowed values for these relationships • Guidance: • UML class diagram representing the conceptual framework of the methodology • Method (usual in the bibliography): • Classes  Concepts • Associations Properties • Aggregations part_of / has_part properties • Is_a  Subconcepts • Multiplicity  Cardinality restrictions

Ontology Implementation

Ontology Implementation. Limitations of the OWL language • Limitations: • Adopted solutions (design patterns): • Inability to representn-ary relationships • Reified relationships • Cardinality restrictions on transitive properties • Transitive superproperties • No native support for processes (focus put on structure rather than behaviour) • Extra classes and relationships

Organization Branch 3..4 [BankManager?] Role BankManager 1 [HeadOfRisk?] [Teller?] [Absent(BankManger)] Role Teller Role HeadOfRisk 2 1 Ontology Implementation. Representation of n-ary relationships • In OWL, all relationships are binary  Impossibility to represent n-ary relationships • Usual and useful conceptual modelling construct • In AMENITIES: e.g., transitions between roles • Situation: An actor playing a role may start playing another one under certain conditions • Three participants in the relationship: • Source role • Destination role • Guard to be satisfied • Design pattern: • A new class whose instances represent instances of the relationship • “N” new functional relationships, i.e., as much as classes participating in the n-ary relationship

Ontology Implementation. Representation of n-ary relationships destination role reified relation source role functional properties guard to evaluate • Subclasses of a new class “Reified_Relation”  Semantic information for ontology editors, software agents and system analysts

Ontology Implementation. Cardinality restrictions on transitive properties • Certain relations exhibit an intrinsic transitive nature (e.g. aggregations): • if A has_part B, B has_part CA has_part C (could be automatically inferred) • In UML it is not possible to specify transitivity (in OWL it is) • Useful to relate concepts • E.g. CSCW_Systems are composed of Organizations, Organizations are composed of Roles, etc.  which Roles make up a particular CSCW_System? • Additionally, convenience of defining certain cardinality restrictions • Organizationsshould be composed ofat least oneRole • Groups should be composed of at least twoActors • Cardinality + transitive is forbidden in OWL for decidability issues

Ontology Implementation. Cardinality restrictions on transitive properties • Design pattern: • A new relationship, “superproperty” with the same intended meaningis defined, e.g., comprises for has_part • Transitivity is declared on the superproperty (i.e., comprises) • Cardinality restrictions are placed on the subproperty (i.e., on has_part, for example)

Ontology Implementation.No native support for processes • Ontology languages lack of native support to represent processes • Essential in CSCW system specification to produce helpful models: • Tasks and activities are to be arranged in ordered sequences. Flows of activities may fork, join, jump backwards/forwards, etc. • Tasks and activities are to be reused in the same or different workflows  A task/activity should be considered irrespective of its actual execution • Unsupported in the AMENITIES conceptual framework • UML activity diagrams are subsequently used in the methodology, but order between activities is not explicitly addressed

Ontology Implementation.No native support for processes • Solution  set of extra classes and relationships: • The execution of each task is modelled as a sequence of steps(new classes) • Each step (but the final_step) may be followed_by (new relationship) one or more steps • At each step it may take place an activity, an action, a workflow fork, join, etc. first_step_1 followed_by fork_step_1 followed_by followed_by appraiser: value headOfRisk: collectApplicantData action_step_1 activity_step_1 performs performs followed_by valuationReport [Finished] inf_object_step_1 followed_by is_produced followed_by join_step_1 OWL Description UML Activity Diagram

Ontology Implementation.No native support for processes

Ontology Implementation.No native support for processes • How about guards? • Rule over the transition between two activities (steps actually...) • 3-ary relationship: source step, destination step and the guard to be evaluated • Reified relation design pattern: followed_by relationship reified in a class • Complicated? • How about the semantics? • Structurally the same as the UML metamodel for Activity Diagrams • One-to-one match • Activity/Action Class  Activity/Action Concept • ActivityNode/ActionNode  ActivityStep/ActionStep • ActivityEdge (reified) Followed_by_Relation • ControlNode (InitialNode, FinalNode, ForkNode,...)  Control_Flow_Step (First_Step, Final_Step, Fork_Step,...) decision_step_1 followed_by following_step final_step_1 followed_by_relation_2 evaluates [Refusal] [Hesitant] followed_by debtReport Status guard_refusal followed_by_relation_1 followed_by [Passed] bankManager+headOfRisk: decideConcession evaluates following_step headOfRisk: prepareDocuments activity_step_1 guard_hesitant followed_by_relation_2 following_step evaluates following_step activity_step_2 guard_passed

AMENITIES conceptual framework classes added forprocess modeling

Modularity in Ontology Design A modular, multi-tier scheme for ontology design to simplify: • Ontology refinement/updates • Modifying a module should not lead to modifications in parts of the ontology that are not conceptually related • Integration with ontologies from other organizations • Relationships between different ontology modules are controlled  no unexpected consequences • Partial reuse • Reuse only the relevant part/module of an ontology

Modularity in Ontology Design.Multi-tier Scheme Amenities-based application ontology for John F. Kennedy aiport Amenities-based application ontology document for C&C Valuation Office Amenities-based application ontology document for enterprises At the top level AMENITIES conceptual framework domain vocabulary of CSCW systems Amenities-based application ontology document for airports Finally, more specific ontologiesrelated to particular collaborative environments Amenities-based application ontology document for Branch Office nº 27 At the next level some instances or more refined classes for more specific domains would be described Amenities-based application ontology document for universities Amenitiesconceptual framework ontology document Amenities-based application ontology document for Bank of Santander Domain ontology Amenities-based application ontology document for Oxford University Amenities-based application ontology document for Notary’s Offices Amenities-based application ontology document for Branch Office nº 15 First level application ontologies Amenities-based application ontology document for Oxford University Amenities-based application ontology document for Klimt Notary’s Office Ground level application ontologies

Analysis of the Specifications. Ontology-based Reasoning • Automated reasoning procedures allow  • Help design and maintain soundontologies by: • Detecting unnoticed logic consequences or inconsistencies • Inferring non-explicit knowledge • Ontologies drive the specification and analysis of the CSCW system

Outline • Introduction • Motivation • Goals • Foundation • Intended Approach • AMENITIES • Ontology-driven modelling and analysis of CSCW systems • Implementation • Modular design • Ontology-based reasoning • Applications of the proposal • Conclusions & Future Work

Applications. Interaction observation systems: the case of COLLECE [Bravo 2007]

Applications. Design of Case-Based Reasoners (CBR)

Visual Tool for Ontology Edition • OWL syntax is rather verbose  ontology edition a cumbersome task • Diagrammatic representations help provide a general view of ontologies at a glance • Aim: Facilitate ontology edition in a modular manner

Visual Tool for Ontology Edition

Conclusions We have extended and formalized the AMENITIES conceptual framework in a formal ontology Several techniques and design patterns have been provided for systematically representing usual conceptual modelling constructs in OWL We have provided a set of classes and relationships that enable the description of workflows in the OWL language We have defined a mapping between the entities of the UML metamodel for activity diagrams and a set OWL constructs to describe workflows without information lost We have devised a modular approach for the construction of collaborative system ontologies. The resulting ontologies are formal underlying CIM’s for an ontology-driven engineering approach to the development of collaborative systems

Conclusions We have presented a formalization of collaborative-system models by means of OWL ontologies, that facilitates: Early detection of inconsistencies and/or meaningless concept structures Inference of non-explicitly declared facts Further reasoning capabilities on the order of the activities in a workflow We have devised an interaction observation system that makes use of ontologies to obtain analysis descriptors We have made used of ontologies to model the structure of case descriptions to be subsequently used by CBR systems in solution searching and retrieval Finally, we have started the development of a visual ontology editor intended to guide the designer in the modular construction of ontologies

Future Work • Definition of a service ontology • Service Oriented Computing • Transition from computation-independent to platform-independent models • Inclusion of goals in the ontology • Most of groupware fails in goal analysis • In CSCW different entities have different goals • Goals affect and even conflict one another

Selected publications • Noguera, M., Hurtado, M.V. et al.: “Ontology-driven Analysis of UML-Based Collaborative Processes using OWL-DL and CPN”. Science of Computer Programming, (in press), 2009 • Duque, R., Noguera, M. et al.: “Construction of interaction observation systems for collaboration analysis in groupware applications”. Advances in Engineering Software, Elsevier, 2009. doi:10.1016/j.advengsoft.2009.01.028 • Penichet, V.M.R., Rodríguez, M.L., Lozano, M.D., Garrido, J.L., Gallud, J.A., Noguera, M., Tesoriero, R., Hurtado, M.V.: “Extending and Supporting Featured User Interface Models for the Development of Groupware Applications”. Journal of Universal Computer Science, Vol.14, No. 19, 3053-3070, 2008 • Garrido, J.L., Noguera, M. et al.: “Definition and Use of Computation Independent Models in an MDA-Based Groupware Development Process”. Science of Computer Programming, Vol. 66, nº1, 25-43, 2007 • Duque, R., Rodríguez, M.L., Hurtado, M.V., Noguera, M., Bravo, C.: “An Architecture to Integrate Automatic Observation Mechanisms for Collaboration Analysis in Groupware”. VII International Workshop on System/Software Architectures, OTM Workshops, Monterrey, México. Springer-Verlag, LNCS 5333, 354 – 363, 2008 • Rodríguez, M.L., Garrido, J.L., Hurtado, M.V., Noguera, M., Hornos, M.J.: Design Guidelines for the Construction of User Interfaces for Collaborative Applications: A Model-Based Approach. Springer, 2009 • Garrido, J.L., Hurtado, M.V., Noguera, M., Zurita, J.M.: “Using a CBR Approach based on Ontologies for Recommendation and Reuse of Knowledge Sharing in Decision Making”. 8th International Conference on Hybrid Intelligent Systems (HIS 2008). IEEE Press, 2008, 837-842 • Duque, R., Noguera, M., Bravo, C., Garrido, J.L., Rodríguez, M.L.: “Construcción de un Sistema de Observación de la Interacción para Entornos CSCW”. IX Congreso de Interacción Persona Ordenador (AIPO) [Interacción’2008], Albacete, España, Thomsom Scientific. (2008 Jesús Lorés Award) • Noguera, M., Hurtado, M.V., Rodríguez, M.L., Chung, L., Garrido, J.L.: “Description of Collaborative Processes using OWL-DL”. The 2007 International Conference on Software Engineering Research and Practice, Las Vegas, Estados Unidos. CSREA Press, 574-580, 2007 • Rodríguez, M.L., Garrido, J.L., Hurtado, M.V., Noguera, M.: “An Approach to the Model-based Design of Groupware Multi-user Interfaces”. 13th International Workshop on Groupware (CRIWG 2007), Bariloche, Argentina. Springer-Verlag, LNCS 4715, 157-164, 2007 • Hurtado, M.V., Noguera, M., Rodríguez, M.L., Garrido, J.L., Chung, L.: “An Ontology-based Approach to the Modeling of Collaborative Enterprise Processes: Dynamic Managing of Functional Requirements”. Second International Conference on Evaluation of Novel Approaches to Software Engineering, Barcelona, España. INSTICC Press. 87-94, 2007 • Noguera, M., Hurtado, M. V., Garrido, J.L.: “An Ontology-Based Scheme Enabling the Modeling of Cooperation in Business Processes”. International Workshop on Modeling Inter-Organizational Systems, OTM Workshops, Montpellier, Francia. Springer-Verlag, LNCS 4277, ISSN: 0302-9743, 863 – 872, 2006 17 additional publications in refereed journals and conferences...

Thesis defense Modelling and Analysis of CSCW systems:An Ontology-driven Engineering Approach Supervisors: Dr. José Luis Garrido Bullejos Dra. María V. Hurtado Torres Candidate:Manuel Noguera García Departamento de Lenguajes y Sistemas InformáticosUniversidad de Granada

Tesis Doctoral Modelado y Análisis de Sistemas CSCW siguiendo un enfoque de Ingeniería Dirigida por Ontologías Directores: Dr. José Luis Garrido Bullejos Dra. María V. Hurtado Torres Doctorando: Manuel Noguera García Departamento de Lenguajes y Sistemas InformáticosUniversidad de Granada

AMENITIES 2. New conceptual framework

UML Metamodel for Activity Diagrams

Reasoning on Activity Ordering ClassAssertion(decideConcession amenities:Risky) ClassAssertion(giveApproval amenities:Supervision) declaration of the types of the activities particular actions/activities to be performed in every step specification of the control flow between activities ObjectPropertyAssertion(amenities:performs step_w decideConcession) ObjectPropertyAssertion(amenities:performs step_x prepareDocuments) ObjectPropertyAssertion(amenities:generate step_y draft) ObjectPropertyAssertion(amenities:performs step_z giveApproval) ObjectPropertyAssertion(amenities:followed_by step_w fwd_by_x) ObjectPropertyAssertion(amenities:following_step fwd_by_x step_x) ObjectPropertyAssertion(amenities:precede step_w step_x) ObjectPropertyAssertion(amenities:followed_by step_x fwd_by_y) ObjectPropertyAssertion(amenities:following_step fwd_by_y step_y) ObjectPropertyAssertion(amenities:precede step_x step_y) ObjectPropertyAssertion(amenities:followed_by step_y fwd_by_z) ObjectPropertyAssertion(amenities:following_step fwd_by_z step_z) ObjectPropertyAssertion(amenities:followed_by step_w fwd_by_x) inferred inferred inferred summary of the full reasoning process ObjectPropertyAssertion(amenities:precede step_w step_x) ObjectPropertyAssertion(amenities:precede step_x step_y) ObjectPropertyAssertion(amenities:precede step_y step_z) ObjectPropertyAssertion(amenities:precede step_w step_z) inferred

Modelling and Analysis of CSCW systems: An Ontology-driven Engineering Approach