=Paper=
{{Paper
|id=Vol-223/paper-27
|storemode=property
|title=Modeling Holonic Systems with an Organizational approach
|pdfUrl=https://ceur-ws.org/Vol-223/73.pdf
|volume=Vol-223
|authors=Sebastian Rodriguez (UTBM),Nicolas Gaud (UTBM),Vincent Hilaire (UTBM),Abder Koukam (UTBM)
|dblpUrl=https://dblp.org/rec/conf/eumas/RodriguezGHK06
}}
==Modeling Holonic Systems with an Organizational approach==
https://ceur-ws.org/Vol-223/73.pdf
Modeling Holonic Systems with an Organizational approach
Sebastian Rodriguez a Nicolas Gaud a Vincent Hilaire a
Abderrafiâa Koukam
a
Systems and Transport Laboratory, UTBM, 90010 Belfort Cedex - France
Abstract
Complex Systems often exhibit hierarchical structures and multiple levels of abstraction,
and MultiAgent Systems, even if they have proved their adequacy to model such systems,
still remains in their larger part at one or two abstraction levels. It seems uncertain in this
context that MAS will be able to catch efficiently the whole complexity of such systems.
Holonic Multi-Agent Systems and their intrinsic hierarchical structure appears as a natural
alternative. In this paper we propose a generic framework for HMAS modeling based upon
an organizational approach. The means to model a compound holon using organizations and
how to conciliate in a generic way the holonic structure with problem-dependent behaviors, are
detailed. Different aspects related to the holon dynamics : holon creation, members integration
and self-organization are also studied.
1 Introduction
Multi-Agent systems are growing, both in size and complexity [14]. Such systems are considered
today to be well suited to model and simulate complex systems. However, in Complex Systems we
usually find a great number of entities in interaction, acting at different levels of abstraction. In
this context, it seems improbable that MAS will be able to faithfully represent complex systems
without multiple granularities.
For this reason, holonic systems have attracted the attention of researchers. And we can count
today an important number of works dedicated to their study. Their domains of application range
from Manufacturing systems[13], Transports[3], cooperative work[1] or yet radio mobile mesh di-
mensioning [18].
The term holon was coined by A. Koestler in 1967. A holon is a self-similar structure composed
of holons as sub-structures. This hierarchical structure composed of holons is called a holarchy.
A holon can be seen, depending on the level of observation, either as an autonomous ”atomic”
entity, or as an organization of holons. This duality is sometimes called the Janus Effect 1 , in
reference to the two faces of a holon. A holon is a whole-part construct that is composed of other
holons, but it is, at the same time, a component of a higher level holon. Considering the interest
Holonic MAS have suggested, it is not surprising that a number of models and frameworks have
been proposed. However, these models are usually strongly related to their domain of application
and based on specific agent architectures. Few approaches propose a methodology of engineering
for such systems. In [7] authors adopt a methodology inspired from INGENIAS [8] but they lack
support for self-organization and do not detail the interactions dedicated to the holonic point of
the view of the system. In this paper we propose a generic framework for HMAS modeling based
upon an organizational approach. This organizational framework emphasis the separation between
holonic aspects and application dependant aspects. Moreover, the organizational concepts used
enable MAS modeling without making assumptions on agent architecture.
Indeed, several approaches have been inspired from a Social Metaphor, where terms like ”role”,
”group”, ”community” represent the main concepts of the model. We can realize the usefulness of
these concepts when we consider the number of methodologies (e.g. GAIA[20] or MESSAGE [4])
1 Roman god with two faces. Janus was the god of gates and doorways, custodian of the universe and god of
beginnings
and (meta-)Models (e.g. AGR [5], RIO [11] or MOCA [2]) using them. By considering organizations
as blueprints that can be used to model a solution to a problem, we believe that an organizational
approach encourages a modular and reusable model [12]. Based on these elements, we have selected
the RIO model [11, 10]. This model offers the advantage of providing a formal specification of its
main concepts using the OZS formalism [9].
In this paper we propose a generic framework for HMAS modeling based upon an organizational
approach. This framework has been formalized using RIO and OZS. The formal specification of this
framework is out of the scope of this article, for more details the reader can refer to [16, 18, 15]. The
paper is organized as follows. First, in section 2, we will discuss how can we model a super-holon
using organizations, and how to represent its structure as well as the goal-dependent behaviors of
the members. Section 3 discusses how to integrate new members and how to create this type of
entities. Finally, section 4 concludes and presents future research directions.
2 A Generic Framework for Holonic Systems Modeling
Our framework is based on an organizational approach to minimize the impact on the underlying
architecture. However, in order to maintain this framework generic, we need to distinguish between
two aspects that overlap in a holon. The first is directly related to the holonic character of the
entity, i.e. a holon is composed of other holons. And the second is related to the problem the
members are trying to solve. For example, lets consider a research laboratory in a university. The
holonic aspect makes reference to the fact that the researchers compose and manage the laboratory.
We call this a holonic aspect since every holon, no matter the application, is always composed of
other holons. On the other hand, the laboratory is created with a specific purpose and, thus, to
fulfill a number of goals/tasks in the system (e.g. complete a research project). How the members
organize and interact so that the super-holon can achieve its goals is specific to the application or
domain of application. Even more, the members of two different super-holons may follow different
interaction patterns to achieve the same result.
So, the first aspect is common to all holonic systems, while the second is directly related to the
domain of application.
These two aspects plus a third, HMAS Dynamics, constitute the three parts of our framework.
The first part is the holon’s structure and management. A super-holon is an entity in its
own right, but it is composed by its members. This part of the framework consider how the
member organize and manage the super-holon. The second part is goal-dependent interactions.
Super-holons are created with an objective and to fulfill certain tasks. To achieve these goals /
tasks, the members must interact and coordinate their actions. Our framework also offers means
to model these aspects of the super-holons functioning. Eventually, the third part is Dynamics.
It is an inherent characteristics of MAS. The framework considers in particular two of the most
attractive characteristics of Holonic MAS : Merging (Creating and Joining a super-holon) and
Self-Organization.
These three parts of our framework will be successively detailed in the following section.
2.1 Holon’s Members Modelling
The first question to tackle is how are holons organized internally to generate and manage a super-
holon. Three different structures were proposed by [6] for holonic multi-agent systems : Federation
of autonomous agents, Moderated Group and Fusion 2 .
In our approach we have adopted the moderated group as management structure. This decision
is based on the wide range of configurations that are possible by modifying the commitments of the
members toward their super-holon (see figure 1). Indeed, if all members can moderate the group
than it is equivalent to a federation and if a single member has all power over the members than it
is equivalent to fusion.
In a moderated group, we can differentiate two status for the members. First, the moderator
or representative, who acts as the interface with non-member holons, and, second, represented
members, who are masked to the outside world by their representatives.
2 Originally called a Merge into one in [6]
Figure 1: Autonomy of the members
Figure 2: Department and Laboratory Holons
Even if we use the name ”Moderated Group” for compatibility with earlier works in this domain,
it can be misleading. As we see it, the structure does not necessarily introduced any authority or
subordination. The term ”Moderated ” makes reference to the different status found in the group.
We can then adapt this organization by giving the representatives specific authorities according to
the problem or constraints.
In order to represent a moderated group with an organizational approach, we need to identify
a set of roles that can represent these concepts. We have chosen to use four roles to describe a
moderated group as an organization : Head, Part, Multi-Part and StandAlone. The three first roles
describe a status of a member inside a super-holon. The Stand-Alone role represents, on the other
hand, how non-members are seen by an existing holon.
Inside a super-holon, members can play three different holonic roles: Head, Part and Multi-
Part. The Head role is the representative or moderator of the group. Represented members can
either play P art or M ultiP art role. P art role is played by those holons belonging to only one
super-holon. And Multi-Part role by those holons shared by more than one super-holon. We call
these roles holonic roles. The adjective ”holonic” is used to distinguish these roles (present in every
holon) from the roles used to model application-dependent behaviors.
If we isolate the Computer Science Holon, the Laboratory Holon and their components from the
university example and we add these holonic roles, we obtain the figure 2. P art role players for the
laboratory represent researcher that belong only to the laboratory, e.g. full time researchers. On
the other hand, some researcher may, in addition to their activities in the laboratory, give lectures in
the computer science department. These holons, like holon RP in figure 2, belong to both holons
simultaneously and thus they play the M ultiP art role. In this example, the department and
laboratory directors would be the Heads of the C.S. Department and the Laboratory respectively.
Lets now consider only the members of one super-holon. We can see the super-holon as a set
of sub-holons in interaction. If we only look at the holonic related interactions, we obtain the RIO
Diagram shown in figure 3. This organization, called Holonic Organization, makes abstraction of
application-dependent interactions to concentrate solely in the status and behavior of the members
from the super-holon point of view. An instance of this organization is called a Holonic Group. As
for the roles, the term “holonic” is intended to distinguish this group (present in every holon) from
other groups used to describe goal-dependent interactions. Every member of a super-holon must
play at least one role in the holonic group. Like this, a super-holon contains at least one group that
identifies the status of its members. We detail now each of these roles.
The representatives of the super-holon play the Head role. A Head member becomes then part of
Figure 3: RIO Diagram of the Roles played by members
the visible face of the super-holon. This means that the head becomes a kind of interface between
the members of the holon and the outside world. The head role can be played by more than one
member at the same time.
The members can confer the head a number of rights or authorities. According to the level of
authority given to heads, super-holon can adopt different configurations. Thus, the Head role
represents a privileged status in the super-holon. Heads will generally be conferred with a certain
level of authority. However, these members have also an administrative load. This load can be
variable depending on the selected configuration. Several Heads may be present in a same holon.
They constitute the interface of the holon with his environment. For example, in the university
department example of figure 2 the head role may be played simultaneously by the director and
the secretary. Depending on the external stimulus one or the two will be influenced and they can
interact so as from the external point of view there only exist one head.
It is important to remark that when a set of holons merge into a super-holon a new entity appears in
the system. In this case, they are not merely a group of holon in interaction as in ”traditional” MAS
theory. The super-holon is then an entity of its own right. Thus, it has a set of skills, is capable of
taking roles, etc. At the same time, as Heads constitute the interface of the super-holon, they are
in charge of redistributing the information arriving from the outside. And, thus to ”trigger” the
(internal) process that will produce the desired result. We will discuss this issue further when we
introduce how task-related interactions can be modeled (cf. 2.2, page 5). The P art role identifies
members of a single holon. These members are represented by Heads within the outside world.
While the holon belongs to a single super-holon, it will play this role. However, when the holon is
not satisfied with its current super-holon it has two possibilities. The first is to quit its super-holon
entirely and try to find a new holon to merge and collaborate with. The second is to try to merge
with a second super-holon while remaining as a member of the first super-holon. In this case the
holon will change his role to M ulti − P art.
The M ulti − P art role is an extension of the Part role. It puts emphasis on a particular situation
when a sub-holon is shared by more than one super-holon. Examples of this type of situation can be
easily found. For instance, in our University example, holon RP is a researcher in the laboratory
and at the same time a lecturer in the Computer Science Department (c.f. figure 2) There are
several reasons to differentiate the Part from the Multi-Part role. First, a set of problems can arise
from the fact that the shared holon is represented by more than one Head. Imagine for instance that
a holon offers services that are conflicting, e.g. a create/access/destroy mechanism to a resource.
If this holon is shared by several super-holon, it might be possible that it receives a contradictory
request from its heads, like destroy / access the resource at the same time. We could say that three
types of conflicts can arise from a shared member :
• Interest conflicts : The super-holons do not share the same goal, or they have contradictory
objectives.
• Authority Conflicts : The representatives of the super-holon request contradictory action to
the shared member.
• Unbalanced Authority Conflicts : One of the super-holon’s Head has more power than the
other over the shared member.
Several problems can appear as a combination of these conflicts. For instance, in open systems,
a self-interested head could use its authority over a shared member to avoid the progress of other
holons.
Beside these problems, shared holons can be the cause of bottle-necks and performance issues.
These cases must be analyzed in detail to maintain the coherence and stability of the designed
system.
Even if we have only considered the possible disadvantages related to shared member, MultiPart
holons offer also a great number of interesting possibilities.
One of such possibilities is Message Forwarding. This consists of allowing MultiPart holons to
forward messages from the members of one super-holon to members of the second super-holon. For
instance, if a researcher wants to delegate a task to a student, he could ask a share member (e.g.
RP in figure 2) to look for a candidate and delegate the task. This could reduce the administrative
load of head and avoid ”formal requests” between the laboratory and the C.S. department.
Other possibility is to implement trust mechanism to accept members introduced by shared
holons. This mechanism was used in [17] to describe the environment as a holonic organization.
2.2 Goal Dependent Interaction Modelling
The previous section introduced the holonic organization (fig. 3) that allows us to describe the
different status of the members and how they manage the super-holon.
However, we can not neglect the fact that this description would be incomplete if it does not
include the interactions of the members concerning goal-driven actions.
In order to achieve its objective, the super-holon will often need to accomplish a number of tasks.
Thus, the members need to organize internally to distribute sub-tasks, exchange information, etc.
These tasks are usually application dependent, and variate from holon to holon. These domain
dependent organizations are called Internal Organizations.
Like this, the holonic non atomic agent (instantiating the model) contains :
• a unique Holonic Group, instance of the Holonic Organization, which defines how are orga-
nized the members. All members of the (super-)holon must belong to this group.
• a set of groups, instances of the Internal Organizations, created to coordinate the interactions
of the members. These groups are created based on the objectives / tasks of the members.
A group may contain only a subset of the members of the super-holon.
To clarify this idea, lets consider a Department of the university. The department is modeled
using two internal organizations. The first, shown in figure 4, represents the Council, defining how
decisions are taken and who is involved in the process. The second represents a specific Lecture,
describing the interactions between the students and their professor, depicted in figure 5. A number
of instances of this organization may be present in a department at the same time. Figure 6 presents
an example of the groups instantiating the internal organizations of the Department holon. The
sub-holons of the Department Holon are inside a dash line cylinder. Each sub-holon is tagged with
the Holonic Role it plays. All members must play one of the holonic roles that defines its status in
the super-holon. We find then two groups, noted g1 : Lecture and g2 : Council. The denomination
g1 : Lecture indicates that group g1 is an instance of the Organization Lecture. The head of the
super-holon plays the role Member in the group g2 and the role Professor in the group g1.
Using this approach, the behavior and interactions of the members can be described indepen-
dently of their roles as a component of the super-holon.
The main advantages of this approach are :
• Clear separation between the Holonic-related (Holonic Organization) and the domain-specific
behaviors (Internal Organizations).
• Modularity in the description of the different Organizations. We can associate an organization
to each task / goal without modifying existing ones.
Figure 4: Council Internal Organization Figure 5: Lecture Internal Organization
Figure 6: Computer Science Internal Organizations
• It encourages a reusable modeling through the use of organizations as description unit (favors
the use of Organizational Design Pattern).
• This approach let us break the intrinsic recursivity of holons in the modeling phase. The
designer can describe the interactions of the members without having to take into account
whether that member is an atomic holon or not.
• Complex mechanism for task distribution, decision making, cooperation, can be easily intro-
duced into holons.
The description of a holon involves then a number of organizations. The only mandatory
organization is the Holonic Organization that describe the member’s status. Others organizations
can be added to describe additional behaviors required for the functioning of the super-holon.
3 Holon Dynamics
Our framework considers two important aspects of HMAS dynamics, (1) creation and integration
of new members, and (2) self-organization. The self-organization module proposed for HMAS is out
of the scope of this paper, interested readers may refer to [15] for details on the self-organization
module. [16] introduces properties proofs about the self-organization module.
So, in this section, we will concentrate on the creation of new super-holon in the system and
the integration of new member into existing holons. This process is called Merging.
New super-holons can be created either by a set of existing holons that merge into a super-holon,
or by decomposing a holon into subcomponents. We will not detail further the decomposition of
a holon, since in this case, the super-holon is capable of defining the intentions of its components.
Thus, controlling how member will interact and even choose a specific architecture for the sub-
holons. In this work, we are interested with the creation of super-holon from existing holons.
Figure 7: RIO Diagram of the Merging Organization
The Merging interaction is a particular interaction between two holons that want to create a
new entity that assembles them. We can distinguish two types of merging : creation of super-holon
and joining a super-holon.
3.1 Interacting with a Holon : Organization or entity?
Depending on the level of observation, a holon can be seen as a set of groups or as an ”atomic”
entity. So, the obvious question that comes to mind is : when does an outside holon see the
super-holon as an autonomous (atomic) entity and when as a group of sub-holons that it can join?.
From a theoretical point of view, we do not need to make a difference, since the super-holon is
an entity that can merge into a higher level holon. However, from a practical point of view, it may
be desirable, even necessary, that external holons can integrate existing super-holons.
If we do not allow the inclusion of new members after the creation of the super-holon, every
time two holons merge, a new level will be added to the holarchy. This could lead to a (very) high
numbers of levels and could cause important overheads when members need to communicate.
On the other hand, if we allow non-members to merge with existing super-holons, we can
considerably reduce the number of levels in the resulting holarchy.
Even if in both approaches the highest level holons may exhibit the same capacities and behavior;
in practice, costs associated with the first configuration may prove inefficient or improper for the
problem’s constraints.
3.2 Integrating new members
In order to support the integration of new member, we need to provide external holons with a
”standard” interface so they can request their admition. From the super-holons point of view,
external holons are seen as StandAlone role players.
When a super-holon is created, only Heads belong to the interface of the super-holon. Thus,
other members (P art and M ultiP art) should not be visible by external holons. This is modeled
by the organization presented in figure 7. In this organization, StandAlone holons may interact
only with the heads of the super-holon.
This organization enables StandAlone holons to interact with the representatives. In this orga-
nization we find the M erging interaction that provides means for a holon to request admition as a
new member.
The StandAlone role represents a particular status inside a holonic system. In contrast to the
roles presented previously, this role represents the way an existing super-holon sees a non-member
holon.
Until now we have discussed roles that are present inside a super-holon. But a holon may also
interact with other holons without necessarily creating / merging into a higher-level entity. In
this context, a holon is seen as an autonomous, atomic entity. This brings us to an important
concept, the different faces of a holon are independent. This means that even if a holon is seen as
a Stand-Alone at one level, it can be composed by substructures at another level. We use the term
Face with correspondence to Koestler’s Janus Face characteristic of holons. In this sense, one face
-looking up- presents the holon as an autonomous entity, the other -looking down- as a group of
sub-holon in interaction.
An interesting characteristic of this approach is that Stand-Alone presents a standardized view
of non-members.
3.3 Creation of new Holons
The merging process may also be used between holons to create a new entity (super-holon) in the
system. In this case, all rules that will govern the life of the super-holon have to be defined. From
an engineering point of view, different approaches can be used.
The first approach is to predefine the holarchy. The holons were conceived so that the rules
for the construction of the super-holon are predefined and known by members in advance. This
approach may be usefull when developping closed application or when the constraints are known
in advance [17]. The adaptivity of these types of system will remain constrained to the anticipated
cases only, and will probably prove impossible to use in large open environments.
The second approach is based upon negotiation. The Merging process foresees a mechanism to
negotiate the configuration of the super-holon. This approach allows a wider range of applications,
and improved adaptive capabilities. But the negotiation process may induce important overheads.
A combination of this and the previous approach could help reducing the overhead.
Eventually, the third approach is evolutive. The super-holon is created with a minimum of
engagements of the members. The members can then increase their commitment toward the super-
holon when they consider it useful. The minimal rules set contains only one rule, which defines how
new engagements (rules) are adding the super-holon. Using this rule with a voting mechanism, any
new rule or modification of it can be obtained. The FORM framework proposed by [19] describes
such a method for task-oriented systems.
A Predefined mechanism can be useful for closed, rather small, systems. However, it seems
improbable that such a mechanism can be used in an open untrusted environment.
The Negotiation is what we might call a ”generic” approach. However, other problems are to be
considered, for instance, the communication language used in the negotiations. In addition, trying
to define all rules of a super-holon may prove to be a consequent task, introducing an enormous
overhead to the creation of the super-holon.
4 Conclusion
In this paper we have presented a novel way of modeling holons and holonic systems. In contrast
to current trends in holonic systems modeling, we have selected an organizational approach. This
allows us a flexible, yet powerful, way of describing holons.
We take advantage of the organizational approach at different levels. First, the model in not spe-
cific to any particular domain of application. Second, it encourages well-known software engineering
good practices, like separation of concerns, modularity, etc.
In addition, we can profit from the experience and research in the field of organizational mod-
eling. Indeed, we can easily imagine to adapt existing organizational-based methodologies such as
GAIA or MESSAGE. In fact, we are already working in the first steps towards such a methodology
for HMAS[15].
This framework has already been used to address real-world problems such as the Adaptive
Mesh problem [18, 16] and large scale simulations [17]
Forthcoming works will address the development of a methodology for holonic multi-agent sys-
tems integrating Organizational Design Patterns. In addition, the significant future task is the
development of CASE tools for the design, modeling and deployment of HMAS. We are currently
working on an Eclipse plugin for this purpose.
References
[1] E. Adam, R. Mandiau, and C. Kolski. Homascow: a holonic multi-agent system for cooperative
work. In 11th International Workshop on Database and Expert Systems Applications, pages
247–253, 2000.
[2] Matthieu Amiguet. MOCA: un modèle componentiel dynamique pour les systèmes multi-agents
organisationnels. PhD thesis, Université de Neuchâtel, 2003.
[3] H.-J. Bürckert, K. Fischer, and G.Vierke. Transportation scheduling with holonic mas - the
teletruck approach. In Proceedings of the Third International Conference on Practical Appli-
cations of Intelligent Agents and Multiagents, pages 577–590, 1998.
[4] Giovanni Caire, Wim Coulier, Francisco J. Garijo, Jorge Gomez, Juan Pavón, Francisco
Leal, Paulo Chainho, Paul E. Kearney, Jamie Stark, Richard Evans, and Philippe Massonet.
Agent oriented analysis using message/uml. In Michael Wooldridge, Gerhard Weiß, and Paolo
Ciancarini, editors, Agent-Oriented Software Engineering II, Second International Workshop,
AOSE 2001, Montreal, Canada, May 29, 2001, Revised Papers and Invited Contributions,
volume 2222 of Lecture Notes in Computer Science, pages 119–135. Springer, 2001.
[5] Jacques Ferber and Olivier Gutknecht. A meta-model for the analysis and design of orga-
nizations in multi-agent systems. In Y. Demazeau, E. Durfee, and N.R. Jennings, editors,
ICMAS’98, july 1998.
[6] Christian Gerber, Jörg H. Siekmann, and Gero Vierke. Holonic multi-agent systems. Techni-
cal Report DFKI-RR-99-03, Deutsches Forschungszentrum für Künztliche Inteligenz - GmbH,
Postfach 20 80, 67608 Kaiserslautern, FRG, May 1999.
[7] A. Giret and V. Botti. Recursive agent. In In Proceedings of Iberagents 2002, Agent Technology
and Software Engineering (2002), 2002.
[8] Jorge Gomez-Sanz and Juan Pavon. Agent oriented software engineering with INGENIAS,
2003.
[9] Pablo Gruer, Vincent Hilaire, Abder Koukam, and P. Rovarini. Heterogeneous formal specifi-
cation based on object-z and statecharts: semantics and verification. Journal of Systems and
Software, 70(1-2):95–105, 2004.
[10] Vincent Hilaire. Vers une approche de spécification, de prototypageet de vérification de
Systèmes Multi-Agents. PhD thesis, Université de Technologie de Belfort-Montbéliard, 2000.
[11] Vincent Hilaire, Abder Koukam, Pablo Gruer, and Jean-Pierre Müller. Formal specification
and prototyping of multi-agent systems. In Andrea Omicini, Robert Tolksdorf, and Franco
Zambonelli, editors, Engineering Societies in the Agents’ World, number 1972 in Lecture Notes
in Artificial Intelligence. Springer Verlag, 2000.
[12] Vincent Hilaire, Olivier Simonin, Abder Koukam, and Jacques Ferber. A formal framework to
design and reuse agent and multiagent models. In James Odell, P. Giorgini, and Jörg Müller,
editors, Agent Oriented Software Engineering, 2004. to appear in LNCS n3382.
[13] Francisco Maturana, Weiming Shen, and Douglas Norrie. Metamorph: An adaptive agent-
based architecture for intelligent manufacturing. International Journal of Production Research,
37(10), 1999. 2159-2174.
[14] James Odell, Marian Nodine, and Renato Levy. A metamodel for agents, roles, and groups.
In James Odell, P. Giorgini, and Jörg Müller, editors, Agent-Oriented Software Engineering
(AOSE) IV, Lecture Notes on Computer Science. Springer, 2005.
[15] Sebasitan A. Rodriguez. From analysis to design of Holonic Multi-Agent Systems: a Frame-
work, methodological guidelines and applications. PhD thesis, Université de Technologie de
Belfort-Montbéliard, 2005.
[16] Sebastian Rodriguez, Vincent Hilaire, and Abder Koukam. Fomal specification of holonic
multi-agent system framework. In International Conference on Computational Science (3),
volume 3516 of Lecture Notes in Computer Science, pages 719–726. Springer-Verlag, 2005.
[17] Sebastian Rodriguez, Vincent Hilaire, and Abder Koukam. Holonic modelling of environments
for situated multi-agent systems. In Second International Workshop on Environments for
Multiagent Systems @ AAMAS 2005, pages 133–138, 2005.
[18] Sebastian Rodriguez, Vincent Hilaire, and Abderrafiâa Koukam. Towards a methodological
framework for holonic multi-agent systems. In Fourth International Workshop of Engineering
Societies in the Agents World, pages 179–185, Imperial College London, UK (EU), 29-31
October 2003.
[19] M. Schillo. Multiagent Robustness: Autonomy vs. Organisation. PhD thesis, Department of
Computer Science, Université des Saarlandes, 2004.
[20] Michael Wooldridge, Nicholas R. Jennings, and David Kinny. A methodology for agent-oriented
analysis and design. In Oren Etzioni, Jörg P. Müller, and Jeffrey M. Bradshaw, editors,
Proceedings of the Third Annual Conference on Autonomous Agents (AGENTS-99), pages
69–76, New York, May 1-5 1999. ACM Press.