=Paper=
{{Paper
|id=Vol-395/paper-7
|storemode=property
|title=Designing MAS Organisation through an Integrated MDA/Ontology Approach
|pdfUrl=https://ceur-ws.org/Vol-395/paper05.pdf
|volume=Vol-395
|dblpUrl=https://dblp.org/rec/conf/models/OkouyaPSSDC08
}}
==Designing MAS Organisation through an Integrated MDA/Ontology Approach==
https://ceur-ws.org/Vol-395/paper05.pdf
Designing MAS Organisation through an
integrated MDA/Ontology Approach?
Daniel Okouya1 and Loris Penserini1 and Sébastien Saudrais2 and Athanasios
Staikopoulos2 and Virginia Dignum1 and Siobhán Clarke2
1
Universiteit Utrecht, The Netherlands,{maatari,loris,virginia}@cs.uu.nl
2
Trinity College Dublin, Computer Science, Ireland
{Athanasios.Staikopoulos, Sebastien.Saudrais, Siobhan.Clarke}@cs.tcd.ie
Abstract. The increasing complexity of distributed applications, soft-
ware services that can be dynamically deployed, adjusted and composed,
paves the way for new challenges in software and service engineering. This
paper describes a novel approach that combines the flexibility of MDE
techniques to deal with the conceptual modelling of MAS and the expres-
sive power of OWL based ontologies to deal with semantics constraints
verification as well as domain knowledge provision of MAS models. We
will illustrate these ideas through the modeling of a crisis management
scenario, using a first prototype of our future Design tool: OperettA.
1 Introduction
Nowadays’ distributed applications based on the notion of service-oriented sys-
tems –which can dynamically adapt, organise, and compose to satisfy with their
networked stakeholders’ needs– are fostering the software engineering research
area with new challenges. As these distributed systems have to be deployed
within real organisational contexts, adhering with organisational rules, and meet-
ing stakeholders’ expectations, it is crucial to characterise the software architec-
tural and functional requirements in terms of their correlations with the actual
environment. To deliver on this aim, a promising approach in software engineer-
ing has been to build methodologies along with conceptual modelling languages
that better reflect and describe the complex social and human organisational
context where the system-to-be has to be deployed [1][2][3]. For example, in [3]
and [4], an ontology based on the Telos language has been presented to describe
the conceptual model of the Tropos methodology.
In this paper, we describe some achievements and future improvements of
a MAS development framework, OperettA [5], which is based on the OperA
methodology [1]. Using a simplified crisis management scenario, we will illus-
trate how the Operetta’s conceptual modelling language –which adheres to a
?
This work has been performed in the framework of the FP7 project ALIVE IST-
215890, which is funded by the European Community. The authors would like
to acknowledge the contributions of their colleagues from ALIVE Consortium
(http://www.ist-alive.eu)
Model Driven Engineering approach– can be integrated with ontology represen-
tation languages as OWL. Moreover, this approach allows designers for both the
verification of the semantics and the provision of domain specific knowledge of
the MAS design models.
Model Driven Engineering (MDE) refers to the systematic use of models as
primary artefacts throughout the Software Engineering lifecycle. The defining
characteristic of MDE [6] is the use of models to represent the important artefacts
in a system, be they requirements, high-level designs, user data structures, views,
interoperability interfaces, test cases, or implementation-level artefacts such as
pieces of source code. The Model Driven Development promotes the automatic
transformation of abstracted models into specific implementation technologies,
by a series of pre-defined model transformations.
The paper is organised as follows: Section 2 presents the methodological con-
text of our approach with a motivation example. Section 3 provides an overview
of our approach. Section 4 summarises the main characteristics and benefits of
the approach adopted, which is partially implemented within the OperettA tool.
2 A Methodological Context
2.1 OperA overview
OperA [1] is an engineering methodology based on organisational abstractions,
suitable both to model and study existing societies, as well as to develop new
systems that participate in an organisational context. The main focus of OperA
enable a suitable balance between global aims and requirements agent autonomy,
their coordination needs, and environmental stakeholders’ needs.
The development framework for agent societies, proposed in OperA, is com-
posed of three conceptual design models: Organisational Model, Social Model,
and Interaction Model, as detailed in [1]. In this paper, we illustrate our ideas by
only using some concepts and diagrams belonging to theOrganisational Model. It
contains the description of the roles, relations and interactions in the organisa-
tion. It is constructed based on the functional requirements of the organisation.
The social model and the interaction model are the link between the organisa-
tional description and the executing agents.
2.2 Running scenario
Using an example taken from the Dutch procedures for crisis management, we
provide a conceptual model based on organisational and social concepts. The
modelling phase is conducted according to the OperA methodology [1] using
the OperettA tool [5] for graphical representation and verification of the model.
This scenario will be used along the paper to explain the development framework
properties.
The structure diagram depicted in Figure 1 represents the crisis situation. It
specifies the responsibilities and goals of each role, e.g., each time an emergency
call occurs to the Emergency Call Center, this role alerts the Fire Station entity,
informing about the location in which the (possible) disaster is taking place. The
Fire Station is responsible to build the appropriate fire brigade and depends on
the established Firefighter Team in order to achieve the objective extinguish the
fire. When the team arrives at the accident location, it has to decide (based on
its personal experience) the severity of the disaster. Only after this evaluation
is reported, an intervention decision is taken. For example, according to local
rules, the evaluation should comply with some standardised emergency levels,
as established by the Dutch Ministry of Internal Affairs. For the sake of sim-
plicity, we consider that Firefighter Team sets up a strategic intervention based
on the results of two evaluation criteria: damage evaluation and fire evaluation.
Based on the number of wounded, Firefighter Team decides on the necessity or
not to ask for ambulance service. Moreover, the Firefighter Team checks if the
damage involves building structures in which case police intervention is neces-
sary to deviate traffic. From the fire evaluation criterion, Firefighter Team can
decide whether it is the case or not to ask Fire Station for a Firefighting Truck
intervention. As described in [1], the Social Structure is further detailed by in-
teraction structure diagrams to model activities among and within roles in order
to achieve their objectives. Such activities are called scenes.
Fire_Station
(fs)
First_Aid_
(ef) (el)
Station
(fas) (as)
Firefighter_ Emergency
Team _Call_Center
(ft) (ecc)
(dt) (dbf)
Firefighting
Police_Station
_Truck
(ps) (fft)
Fig. 1. Social Structure diagram: Fire Station organisation (O) example.
Notice that, the specification provided at this time is not sufficient to give a
complete picture about the know how required to software systems to achieve
the modelled organisational objectives. Nevertheless, the level of abstraction
achieved provides enough anchor points for agents to coordinate their activity
without fully pre-specifying the capabilities of the agents and therefore limiting
flexibility.
3 Approach overview
3.1 A meta-level view of conceptual models
In order to effectively deal with the MAS development, the proposed approach
takes into account both the syntax and the semantics of a MAS, through an
integration of MDA with Reasoning and Domain Knowledge specification Based
on Ontology. Fig. 2 illustrates the architecture of our approach. The central
part corresponds to the OperA metamodel, which provides the syntax of MAS.
The right part provides the actual semantics of MAS, which is described by
the OperA ontology. The MAS ontology instantiation will be automatically pro-
duced from the MAS model, which is created with the OperettA tool. Next,
the MAS ontology instantiation will be semantically checked against the OperA
ontology, see section 3.2. The left part provides an interaction between existing
domain ontologies and MAS models. The interaction is maintained by defining
transformations relation between the OperA metamodel and EODM3 . EODM is
an implementation of the ODM standard from OMG, defining metamodels for
RDF(S) and OWL, see section 3.3.
Relations Associated with
EODM
Opera Metamodel Opera Ontology M2
Metamodel
Conforms to
Conforms to
Conforms to
Ontology
Import/export Produces MAS ontology
Domain ontology MAS Model
instantiation M1
Model (e.g.: FireStation)
(e.g.: FireStation)
External domain modelling MAS modelling Semantic constraints verification
Fig. 2. Overview of our approach.
3.2 Reasoning with models compliant with OperA ontology
The first aspect of our integrated approach is directed toward reasoning on our
models using logics, with description logic as our language mainly dedicated
at reasoning on the structural aspect of our models. This will provide us with
the ability to use the power of descriptive logic along with associated reasoners,
combined with techniques to formally analyse our models and enhance their
quality.
At the meta-level, the abstract syntax is defined through metamodelling and
the semantics is based on description logic. This results in the OperA ontology,
which formalises OperA conceptual framework concepts and their relationships,
as well as domain independent OperA semantics constraints. Meanwhile, the
integration of the metamodelling and ontologies supports domain specific lan-
guages and also offers the opportunity to query the models. Indeed, as the OperA
metamodel is associated to the OperA ontology, a MAS model is associated to
a MAS ontology instantiation. Consequently, the semantics of our models are
stored in the MAS ontology instantiation, which is automatically produced using
3
http://www.eclipse.org/modeling/mdt/?project=eodm
the MAS model (following a straightforward transformation). Hence, it allows for
the designer, the verification and validation of models using ontologies; namely,
the application of description logics for reasoning about the OperA language. In
the following, some examples of semantics constraints, that we are interested in
verifying, have been proposed.
– Checking if the objective of a dependency is an objective or a sub-objective
of the dependency’s initiator. For instance, in the running scenario, this
would mean verifying that the role fire-station possesses an objective or sub-
objective extinguish fire as it appears to be dependent on Firefighter Team
for it.
– Checking if each dependency is realised by at least one scene.
– Checking if roles are involved in a dependency, do indeed cooperate in at least
one realisation scene of that dependency. Again, referring to the scenario,
there must be at least one realisation scene of objective deal with big fires
dependency in which Firefighter Team and Firefighter Truck must cooperate.
– Checking that each role posses at least one dependency link.
The approach described above has been partly implemented in and illustrated
by the OperettA prototype [5]. The results obtained with that prototype have
encouraged us to move towards a more standardised and accessible version of
the tool. The actual version is currently under development using Eclipse.
3.3 Conforming design models to domain ontology
The second aspect of our approach permits the use of ontology within our models
as the source of domain specific related knowledge, necessary for the description
and support of roles interaction and communication in OperA organisation and
at a lesser extend, domain specific semantics constraints enrichment. That is,
domain ontologies are integrated at the model level. They are defined, used and
imported within the OperA modelling language as well as exported from it.
For the latter two, a relation is defined at the meta-level, between the Eclipse
Ontology Definition Metamodel and the OperA metamodel enabling the interaction
with standard ontology representation languages like OWL. Meanwhile, in the
ontological world the integration is at the same level. That is, the OperA ontology
and domain ontology are at the same level within logic hierarchy; paving the way
for the analysis of the overall structural aspect of the organisation, consisting in
querying one knowledge base being the combination of the OperA ontology, the
Domain Ontology and the derived MAS ontology instantiation.
Firstly, a vocabulary is available for describing interactions and supporting
communications related to a domain. Referring back to our Fire Station organ-
isation, given the equivalent formal notation for the objective extinguish –e.g.,
Extinguish-Fire(L : location)– of the Firefigther Team role, the concept of Lo-
cation must be defined in the Domain ontology, otherwise the parameter type
will not be available when defining the objective. Furthermore, at run-time, this
ontology will be used by members of the organisation in order to communicate.
Secondly, the OperA Ontology can be enlarged by further modelling domain-
specific constraints enriching the generic semantic constraints. It provides the op-
portunity to define modelling rules within the domain ontology as (re)configuration
rules e.g., a specific domain could forbid more than 2 dependencies between two
specific roles.
This second aspect provides a separation of concerns for knowledge taking
into account its domain specific part and enabling at the same time the tool to
tailor himself based on it.
4 Conclusions
This paper describes the features of an implemented design tool, OperettA,
based on the OperA methodology. This enables the construction of a devel-
opment framework to support software and services engineering. Besides, this
contributes to the achievements of a more general research objective established
within the ALIVE project. Specifically, the ALIVE project combines cutting
edge Coordination technology and Organisation theory mechanisms to provide
flexible, high-level means to model the structure of inter-actions between services
in the environment.
The proposed approach (partly) implemented in OperettA deals with tech-
niques to integrate features of the model driven architecture (MDA) with fea-
tures of the ontology languages (OWL). Main benefits of our approach come
from the fact that it provides a model driven approach for the specification of a
MAS dealing with its semantics and its provision of domain specific knowledge.
Hence, our approach allows designers for powerful reasoning mechanisms to be
employed as well as a smart integration of domain specific knowledge that comes
first to refine and enrich (along with further constraints) the specification of the
design model.
References
1. V. Dignum. A Model for Organizational Interaction: based on Agents, founded in
Logic. PhD thesis, Universiteit Utrecht, 2004.
2. Brian Henderson-Sellers and Paolo Giorgini, editors. Agent-Oriented Methodologies.
Idea Group Inc., 2005.
3. A. Fuxman, P. Giorgini, M. Kolp, and J. Mylopoulos. Information systems as social
structures. In FOIS ’01: Proceedings of the international conference on Formal
Ontology in Information Systems, pages 10–21, New York, NY, USA, 2001. ACM.
4. J. Mylopoulos, A. Borgida, M. Jarke, and M. Koubarakis. Telos: representing knowl-
edge about information systems. ACM Trans. Inf. Syst., 8(4):325–362, 1990.
5. D. M. Okouya and V. Dignum. A prototype tool for the design, analysis and
development of multi-agent organizations. In DEMO Session: Proc. of the 7th Int.
Joint Conf. on Autonomous Agents and Multiagent Systems (AAMAS-08). ACM,
2008.
6. J. Bézivin, N. Farcet, J.-M. Jézéquel, B. Langlois, and D. Pollet. Reflective model
driven engineering. In UML, pages 175–189, 2003.