Quality of service measures the conformity of the service with the commitments that STIB makes with and for the customer. This commitment involves putting the customer, the passenger, at the heart of STIB’s concerns and ensuring their satisfaction. One way of doing this is to use "mystery shoppers" external to STIB.

By scrupulously following the passenger's journey, the mystery shoppers observe daily, from the user's point of view, whether the service meets the quality of service desired by STIB, the Region and the customer representatives.

Each year, the mystery shoppers carry out no less than 11,000 measurements and check some 700,000 elements (an element corresponds, for example, to a seat, a stop button, a network map, a gate, a waiting time display, up-to-date information, a route search, the purchase of a ticket, etc.).

These measurements take place in vehicles, at stops and stations, at points of sale, and on the website and mobile application. After analysis, this data allows STIB to measure the performance of the services and the quality provided. And above all, to identify improvement actions that STIB could implement throughout the network in order to offer a better service to passengers.