1 - Predictive maintenance techniques: Part 1 predictive maintenance basics

Abstract

Maintenance philosophies are divided into four different categories: breakdown or run to failure maintenance, preventive or time-based maintenance, predictive or condition-based maintenance, and proactive or prevention maintenance. The basic philosophy behind breakdown maintenance is to allow the machinery to run to failure and only repair or replace damaged components just before or when the equipment comes to a complete stop. This approach works well if equipment shutdowns do not affect production and if labor and material costs do not matter. The disadvantage is that the maintenance department perpetually operates in an unplanned “crisis management” mode. When unexpected production interruptions occur, the maintenance activities require a large inventory of spare parts to react immediately. Preventive maintenance schedules the maintenance activities at predetermined time intervals, based on calendar days or runtime hours of machines. The main disadvantage is that scheduled maintenance can result in performing maintenance tasks too early or too late.With predictive or condition-based maintenance, the philosophy consists of scheduling maintenance activities only when a functional failure is detected. Lastly, with proactive or prevention maintenance it lays primary emphasis on tracing all failures to their root cause.