2.1 Fuzzy Delphi
Delphi technique is a strong process based on the group communication structure used for cases where incomplete and uncertain knowledge is available 19. The main aim is to reach a consensus among experts 20. In the classical Delphi method, experts’ opinions are expressed in the structure of definite numbers, while those who are experts are using their mental competencies to express their opinion, which indicates the uncertainty that governs these conditions. Uncertainty is compatible with fuzzy sets. Therefore, it is better to obtain data in the structure of the verbal variables from the experts and analyze those using fuzzy sets.