In cluster node, when you choose automatic option. This is explanation in details from cluster node's help in sas E-Miner.   The Automatic setting (default) configures SAS Enterprise Miner to automatically determine the optimum number of clusters to create. When the Automatic setting is selected, the value in the Maximum Number of Clusters property in the Number of Clusters section is not used to set the maximum number of clusters. Instead, SAS Enterprise Miner first makes a preliminary clustering pass, beginning with the number of clusters that is specified as the Preliminary Maximum value in the Selection Criterion properties. After the preliminary pass completes, the multivariate means of the clusters are used as inputs for a second pass that uses agglomerative, hierarchical algorithms to combine and reduce the number of clusters. Then, the smallest number of clusters that meets all four of the following criteria is selected.   I hope this what do you want. Thanks ... View more