Simile: a visual modelling environment with potential for modelling agent-based systems


Simile is a visual modelling environment for constructing and simulating the behaviour of models of dynamic systems.   It incorporates both System Dynamics and object-based concepts.   System Dynamics (or compartment-flow) modelling is a way of visually representing models based on a set of ordinary differential equations.  Simile extends this paradigm by enabling a set of System Dynamics symbols to be wrapped up as an object, which can have a fixed or dynamically-varying number of instances.   In addition, Simile supports the concept of an association (relationship) between objects ('owns', 'next_to', etc).    Together, these features mean that Simile can be used to model the internal dynamics and interactions between large collections of objects.

Simile has been developed primarily for ecological and environmental modelling, and thus the emphasis to date has been on providing object-based rather than agent-based functionality.   However, we have recently started to use Simile for modelling combined human-biophysical systems, with a population of households interacting with their natural resources.   This has led to the need to introduce agent-like behaviours, such as decision-making, planning, formation of dynamic social networks, negotiation and the transfer of information.   Some of these can be implemented using Simile's existing modelling constructs, but we are exploring the possibility of enabling Prolog programs to be attached to any object, opening the door to a declarative, logic-based approach for modelling agent-like behaviours.

Links:
http://www.ierm.ed.ac.uk/ame   (AME being the old name for Simile)
http://www.ierm.ed.ac.uk/flores   (FLORES is the international project involved with modelling the interaction between people and their resources in developing countries, using Simile as the modelling platform.)