On Modelling Agent Mobility in Multiagent Methodologies

1. PROBLEM STATEMENT – METHODOLOGICAL SUPPORT FOR SYSTEMS WITH AGENT MOBILITY? A property of agents is the ability to move from one host to another to perform computations. While not all agents require such a property, agent mobility has been recognized as beneficial in a number of applications and a sizable number of mobile agent toolkits have been developed for mobile multiagent applications. While there will be multiagent systems where agent mobility is not needed, we contend that it can be disadvantageous if agent mobility is a concept only confined to (and considered in) the implementation phase, or an after-thought in engineering multiagent systems (e.g., used for optimising applications). The advantages of agent mobility might remain unexploited, adding mobility to agents after the system is implemented can be problematic, or development of multiagent systems where some agents can be mobile might proceed in an ad hoc manner (e.g., the implementation with mobile agents deviates from the design without mobile agents), if agent mobility is not considered in the earlier phases of agent-oriented software development. Whether agents are mobile or stationary does have an impact on the architecture and required components of a multiagent system, and how they can be made so, can be an important factor in deciding which agent toolkit to use for implementation. The why and how of agent mobility, or its dismissal, should be considered, and if needed, its rationale documented at design time. Such consideration of agent mobility should also support toolkit independence (as far as the required functionality will allow). On the other hand, there will some applications where agent mobility is obviously useful and more efficient, but an implementation in some mobile agent toolkit without the auspices of an integrated agent-oriented analysis and design is clearly less than ideal.