1. An expert system, comprising: a data storage device, storing a plurality of models, each model including a plurality of attributes including a variable attribute; a plurality of objectives, each objective including an objective rule for evaluating a characteristic of the model; and a plurality of strategies, each strategy including a strategic rule for modifying the variable attribute; and a processor coupled to the data storage device, the processor including instructions which, when executed by the processor, cause the processor to: evaluate a selected model in accordance with a selected objective and having the variable attribute set in accordance with a selected strategy to determine a characteristic value associated with the selected model and the variable attribute setting; determine, using the objective rule, whether the characteristic value is an improvement over a previous characteristic value; and store a result in the storage device when the characteristic value is an improvement over the previous characteristic value, the result including an identification of the selected model and the variable attribute setting used to determine the improved characteristic value.