In order to avoid the problems that could be slow down and even stop the production, the company must adopt a strategy of maintenance of all equipment throughout their life cycle, which aims are: better management, organization, equipment control and anomaly detection as well as accurate diagnosis of malfunctions. Besides, a bad the nasty maintenance program could be prevented in increased production rates and poor business development, where the maintenance program must move towards predictive maintenance, which contains many NDT (non-destructive testing) techniques such as vibratory analysis, thermography, ultrasonic, radiography, penetrant testing and magnetoscopy. Therefore, the choice of an NDT technique among others on the nature of the physical parameter has to be monitored and according to the criteria of speed, cost, reliability, ease, and safety of each technique. Moreover, some components, have seen that several NDTs can be used, in order to optimize the use and the costs related to these NDTs. Thus; the present work consists of proposing a new methodology for ranking NDT techniques based on priorities. Nevertheless, the proposed methodology has proven its robustness in the study case part of one of the workshops of a phosphoric office.