Multi-criteria decision making (MCDM) techniques are among the methods used by the decision maker in the decision phase in practice, as in the literature. MCDM problems are grouped as classifications and sorting problems according to the type of inclusion or ranking in existing classes. Inverse multi-criteria sorting problem, a new topic in recent years, is defined as choosing among existing actions in order to improve the status of alternatives. In this study, in order to find out which action plan should be chosen for providing the minimum cost for the improvement of public transportation vehicles in case the boundaries of the classes to be assigned are uncertain, the inverse multi-criteria ranking problem is used. Because the boundaries of the classes to be assigned are fuzzy, fuzzy linear programming method will be used to solve the problem.