# Towards Agent Organizations Interoperability: A Model Driven Engineering Approach
## 1 Introduction  
In the research and development of _multiagent systems_ (MAS), one of the central issues is how to conciliate the autonomy of the agents with a desirable and stable behavior of the MAS as a whole. Borrowing ideas from the Social Sciences, some authors have named this issue the _problem of social order_: \"How to obtain from local design and programming, and from local actions, interests, and views, some desirable and relatively predictable/stable emergent result\" [1]. A closely related issue is the _problem of social consensus_ often characterized as how to reach agreement with regard to some aspect or quantity of interest in a network of agents by combining the local preferences or states of individual agents [2, 3]. Both social order and social consensus are fundamental problems in the design of MAS. While social order stresses the idea that agent behaviors must be coherent with the MAS global purpose, social consensus highlights the need of agreement among agents working together for a global purpose. Faced with these problems, especially in the context of open MAS (i.e., systems formed by a dynamical population of agents provided by different developers), several researchers have argued in favour of using the _human organizations_ as a proper metaphor for engineering MAS [4, 5, 6, 7]. Human organizations, whose typical examples are firms, clubs, corporations, etc., are _collectivities_ pursuing _specific goals_ and exhibiting _formalized social structures_[8]. Goals are specific to the extent that theyare explicitly and clearly defined. Social structures are formalized in such a way that patterns of structuring and behaving (such as _roles_, _role relations_, _procedures_, _protocols_, _norms_, etc.) are precisely specified regardless of personal traits and relations of any individual part of the organization. Thus, by conceiving a MAS as an organization--or more generally as a bigger system formed by several organizations, hereafter called _agent organizations_--the basic idea is to promote social order and consensus in a top-down fashion. The idea is to have the agents' actions and interactions governed by formalized \"social structures\", defined above the agents level, in order to enable the MAS (seen as a collective entity) to achieve definite global goals. This emphasis on organizations as a suitable metaphor for engineering social order has led to several proposals of _organizational models_ for MAS design [4]. From the perspective of software development, most of these organizational models can be characterized as _domain specific modeling languages_[9]. That is, they provide a specialized _conceptual structure_ (metamodel) embodied in some _concrete syntax_ (notation) by means of which the designer can write formal representations of the social structure of agent organizations. Such representations, called _organizational specifications_, are then used as specification artifacts driving the development of agents and MAS. On the one hand, the existence of many organizational models favours the organizational design of MAS since, with various proposals, experience and best practices are accumulated. On the other hand, a great variety of organizational models introduces heterogeneity in the development of MAS. As a direct consequence of this heterogeneity, mainly in the case of open MAS, a new and important interoperability issue arises: If to enter and fully work in an organization the agents should be designed to \"understand\" and comply with an organizational specification of a given kind (i.e., conforming to some organizational model), then, in addition to the communication language and the domain ontology, the organizational model is something that the agents are supposed to share in order to properly work together. In other words, how can we provide means for a set of agents, immersed in a common environment, to evolve, reason, decide and interact with each other based on organizational concepts, since their organizational models may differ?