1. A method of tuning an ion beam in an ion implanter, wherein the ion beam is dependent upon a plurality of operational parameters of the ion implanter, the method comprising: retrieving a set of operational parameters at least some of which are stored in a dynamic database; configuring the ion implanter according to the retrieved set of operational parameters thereby to provide an ion beam; optimizing the ion beam by varying one or more of the operational parameters; and updating the operational parameters stored in the dynamic database that changed during optimization with rolling averages calculated using the values obtained for those operational parameters at the end of the optimization.