This study, born as a result of the need to determine the impact of poor adherence to maintenance plans on the main production indicators of a crushing plant. A Montecarlo simulation was performed to determine the relationship and sensitivity between postponement of planned maintenance activities and plant availability. In the same way, a sensitivity analysis was performed to determine the impact of varying the maintenance time and mean production capacity on Overall Equipment Effectiveness (O.E.E.). The proposed approach can be considered as a powerful prioritization tool, since the maintenance manager can measure the effects of postponing preventive maintenance actions on different assets. In that sense, maintainers can define where it is possible to postpone certain activities without affecting importantly the overall production system outputs.