Abstract: Process data mining system and method. The system analyzes data from complex process plants or systems and operates in open-book and closed-book modes. In closed-book mode, the system monitors incoming data sets against pre-defined clusters of data values and generates reports, indicating whether incoming data is a match or a no-match with the pre-defined clusters. In open-book mode, the system generates initial clusters, without having a-priori knowledge of the component or process, and also creates clusters “on the fly”, thereby fine-tuning the analysis. A knowledge base encompasses a combination of parameters for a particular component. Clusters are defined within the knowledge base, each cluster representing a particular operating condition. The system expands clusters, within pre-defined limits, or creates new clusters, as needed, in order to accommodate incoming data values. Newly created clusters are then named, so as to indicate the particular operating conditions.