George Vithoulkas describes the process
As a general rule, VES considers mind symptoms to be more important than local ones. But there are cases in which it may ignore such symptoms in favor of some prominent local keynotes. Many different principles and possibilities are used to decide when this particular decision is applied.
You don’t have to pre-select particular symptoms before using the Expert System. The VES takes care of this itself by using ALL the symptoms and selecting the most appropriate rubrics.
Every time you add a new symptom, VES re-evaluates the whole case and gives you a completely new analysis.