The graph construction and improvement algorithms often need to make a random choice among several equivalent locations to place the next department. Different replications of the same algorithm can thus provide different adjacency graphs. The higher the number of replications, the more likely a good adjacency graph will be constructed. Of course, more replications require more computation time. The default number of replications is equal to 20. In version 4.0 or higher of SPIRAL, the name of this field has been changed to Number of Replications.