**7.4 Preventive maintenance planning**

The button MAINTENANCE ESTIMATION comand, presented in Figure 17, opens the interface for planning preventive maintenance for OEL or for its components, for a determined period and in the required technical and economic conditions, presented in Figure 21.

Fig. 21. Interface for planning PM on the OEL or its components

The influence of the number of renewals *r* [pieces], calculated on the OEL or on its components, allows a study of renewals influence on the reliability at the end of the period of study, presented in Figure 22.

Fig. 22. Influence of the number of renewals

Do to its complexity, the developed program, which was conducted on the basis of theoretical considerations presented in previous sections, allows a much easier assessment of the reliability of the studied system and allows an optimization in planning PM, in different technical and/or economic situations.
