Selection method and history management method of the process model

摘要

A method of managing a process model history having process models stored therein, includes organizing the process models according to first and second priority criteria, wherein each process model is represented according to a combination of a value in connection with the first and second priority criteria. The representation may be coordinate values in a multi-dimensional space having dimensions corresponding to the first and second priority criteria. A degree of separation or relationship to a common point of reference is calculated for each process model, where the point of reference is a value in connection with the first and second priority criteria. A process model may be removed or selected for deletion based on the degree of separation or proximity in relation to the point of reference, subject to the total number of process models identified for the same control routine, and the total number of process models identified for the same operational region.