AN OBJECT-ORIENTED GREENHOUSE SIMULATION SOFTWARE SYSTEM .1. ARCHITECTURE AND FUNCTIONAL DESCRIPTION

An object-oriented software system (GX) representing a new and unique approach to the simulation of greenhouse heat and mass exchanges is de scribed. Its main characteristic is that it greatly facilitates the st udy of the effect of control strategies on heat and mass balances. It thus allows for the development and validation of optimization strateg ies in which a dynamic behavior is desired. Its second characteristic is that it encapsulates the real time and simulation systems into a si ngle structure. Hence, the code written to study the effect of a strat egy on the greenhouse climate and energy use can be deployed and used for the real time operation of a greenhouse. Such a functionality is m ade possible by the use of the Smalltalk programming language which is an open-ended, object-oriented programming and runtime environment. T he technology used in GX represents an alternative to conventional pro gramming approaches, it enables the rapid development of new procedure s and techniques and facilitates the transfer of knowledge to the end user. As such, it is strategic to the development of a ''knowledge-bas ed'' agriculture.