1. An arrangement for use in a control system within a building, the control system having system outputs corresponding to a set of operating parameters, the arrangement comprising: a plurality of sensor microsystems configured to obtain environmental information regarding a plurality of areas in the building; while said building is operating on-line; a processing circuit configured to obtain data representative of the environmental information regarding the plurality of areas in the building operating on-line under a first set of operating parameter values corresponding to the set of operating parameters; cause the building control system to operate on-line under a second set of operating parameter values, wherein a first parameter of the set of operating parameters has a changed value; obtain data representative of the environmental information regarding the plurality of areas in the building operating on-line under the second set of operating parameter values; store the data representative of the environmental information under the second set of operating parameter values in a knowledge base; at a subsequent time, employ the knowledge base to generate a subsequent set of operating parameter values.