Dynamic Preventive Maintenance Method Of Equipment For Lifecycle

Theory of equipment preventive maintenance has been developing continually, butits soundness also has room for development. Time-based periodic maintenance easilyleads to surplus and lack of maintenance because of the ignorance of various changefactors. Faults-based state maintenance, it doesn’t exist a way to predict all of faultsmodes. Meanwhile, in allusion to results of fault prediction, fault danger is differentbecause of different equipment state, and it must be in lack or in surplus if the samemethod is adopted. This thesis proposed a dynamic preventive maintenance method ofequipment for lifecycle, on the basis of the introduction of the lifecycle, it furtherstudied the powerful combination between two method and maintenance differencewithin different fault hazards. It’s mainly about:Evaluation method of equipment lifecycle stage was proposed. For the problem ofhow to scientifically describe the device actual operating state, this thesis proposed away to qualitatively describe and distinguish the age and health status of equipment bybringing in concept of lifecycle, established AHP-fuzzy synthetic evaluation model toevaluated the lifecycle stage that equipment work in to obtained the lifecycle stage ofequipment.Classification method of fault danger levels in different equipment lifecycle stagewas proposed. For the problem of fault danger levels is different in different equipmentlifecycle stage, on the basis of informed of the equipment lifecycle stage, this thesispresented a more detailed classification by using weighted mean method to divideddanger level in different lifecycle stage under same failure mode, treating equipmentlifecycle stage and fault component as weighting factor, and obtained the fault dangerlevel in some equipment lifecycle stages.Dynamic generation rules model was established. On the basis of informed of theequipment lifecycle stage and fault danger levels, this thesis established the dynamicgeneration rules model which treat equipment lifecycle stage and fault danger level asconstraints, selected raising equipment utilization rate and reducing maintenance cost as target. It effectively combined with time-based periodic maintenance and faults-basedstate maintenance. According to the fault danger levels, different maintenance levels beadopted, and achieve the purposes of refinement maintenance.Preventive maintenance job list was generated. On the basis of the dynamicgeneration rules model, this method of generate preventive maintenance job list wasproposed, which generate the job list by making use of the dynamic generation rulesmodel and a knowledge base about fault maintenance. And the preventive maintenancejob list was obtained, maintenance items were determined.At the same time, in case of semiconductors equipment, about proposed method inthis thesis, validation of results and case analysis were both presented. The method canimprove equipment utilization, reduce maintenance costs, and to achieve the lowestmaintenance costs, and effectively prevent the excess and lack of maintenance.