Formulate a polling station location problem, taking into account the following binding constraints: (a) the number of polling stations is fixed for each municipality and calculated according to the number of resident voters, (b) the number of voters assigned to each polling station may not exceed given lower and upper bounds and (c) the suitability of the potential sites is established by specific safety measures on the accessibility and typology of the buildings (e.g. in some countries, only public buildings, such as schools, are eligible). Other soft constraints impose the removal of any difficulty in going to the polls. This typically means that almost the same number of voters is assigned to each polling station, with the aim of limiting possible troubles and disservice (e.g. queues of voters or delays in communicating the vote-counting results). Another important requirement, generally handled as a goal to pursue rather than a constraint, is the minimization of the total distance covered by voters to reach their respective polling stations.