The Periodic Vehicle Routing Problem (PVRP) consists in assigning customer visits to vehicle routes in some periods of a time horizon so as to satisfy some service level requirements that can take the form of frequency of visit, constraint on time lag between visits, or pre-defined visit patterns. We present different variants of this problem and propose a classification. Then, we consider a model for tactical planning for which we propose a heuristic: we optimise the planning of customer visits to achieve both workload balancing and regionalisation of the routes. The objective of regionalisation reflects a desire to specialize routes to restricted geographical area. The standard minimisation of distance travelled is left for the underlying operational decision making model. Our heuristic achieves practical solutions for an industrial instance with 16658 visits to schedule over a horizon of 20 days.