Alberobello, literally “beautiful tree”, is a small town of Bari in Apulia, south of Italy (in the heel of the boot). It has fewer than 1000 inhabitants and is hosts to the famous Trulli, designated World Heritage by UNESCO since 1996. A trullo (singular trulli) is a conical roof construction composed of dry stones, that is to say arranged without mortar. It is a technique used since prehistoric times, like an igloo but with stones. Alberobello has the largest number of trulli.

Trulli attract many tourists and foreigners may even acquire them. In face of the increase in the flow of visitors, parking spaces in the municipality of Alberobello have become rare, with other traffic-related problems such as traffic jams, pollution and tourists less and less satisfied with the transport. The municipality called on an urban planning expert to identify 5 sites to install large parking lots, meeting the UNESCO standards. However, the public funds can cover the construction of only one parking lot. So, the city hired a decision consultant to help them choose.

Given the public nature of the car park project, it was necessary to consider several aspects in the decision: the multiplicity of stakeholders (the local community, the managing entity, the beneficiaries, the inhabitants …); irreversibility linked to the use of public resources; the need for justification and accountability; and lastly, long-term impacts. Thus, the construction of the decision model was only possible after understanding the involvement and opinion of each stakeholder.

The specificities of the 14 entities identified as stakeholders were then integrated into the decision model. It is understood that the objectives of the entities were not the same. The consultant’s job therefore consisted mainly of reuniting opinions, with the active participation of each stakeholder. To date, no computer can replace the consultant in such a task.