Research On Method Of Maintenance Decision Of Engine Cylinder Body Production Line

Equipment is an important part of plant and it is the major means for theproduction in the industry and the symbol of the productivity. With theadvancement of science technologyand the competition in the industry, equipmentis more expensive and the management is more important. New requirements havebeen put forward on equipment maintenance management in various countriesbecause of increasing cost with increasing size of equipment. In the past, when thebusiness managermade adecisionofequipment management becausehe oftenlaidparticularstressontheindividualexperience,theresultwasoftenhighcosting,lowearnings in vain. It can reduce the cost of equipment maintenance, enhance theefficiency of maintenance, facilitate the development of enterprise and improve itsability of adaptation and competition by the research and application of newequipment maintenance decision systems. The study of the theory of maintenancemanagement of manufacturing equipment and the development of maintenancedecisionsystemhavedrawngreatattentionandbecomeoneofthefrontier fieldsofmanagementscienceandartificialintelligence.The latest statistics indicate that $800-1200 hundred million is used tomaintain industry equipments in the United States in one year, and the expensesthat 17 countries of Western Europe expend on maintenance attain to 192 billionDeutsche Mark every year, having a total property of enterprise of 15.2%,whileclosely 300 hundred million RMB is used to maintain equipments in China everyyear.Except forproducingfield,themaintenance cost ofthemilitaryandarmamentalso is veryconsiderable. Statistics accordingtotheAmericanMinistryof NationalDefense, maintenance cost of the military and armament amounts are more than14.2% of the total military expenses for near 50 years, and maintenance cost hasbeenthe heavyburden of theAmericanMinistryofNational Defense.Therefore, itisalreadytheutmosturgencytocontrolthemaintenancecostavailably.The main research of this paper concentrates in a few aspects including theequipment reliability, the model establishment of maintenance and the research ofmaintenance decision-making methods and development of the computerassistancetomaintenancemanagementsystem.Valid data is the foundation of reliability analysis,maintainabilityanalysis,guaranty analysis and maintenance decision.The objects of the researchand applyingto are a certain cylinder bodyworkshop section.We have collected allof the breakdown records and maintenance records from July 2001 to December2004 of the cylinder bodyworkshop.The aim of that is classifythe important gradeoftheequipmentsthoughtheanalysisonmaintenancetimes,maintenancetimeandshut down time etc.,and according to which reasonable maintain method can bechosen.Ultimately,the highest utilization rate and operation efficiency of theautomatic-production-lineequipmentscanbeachieved.Firstly,under the analysis on a great deal of operation record,we build up amanufacturing system reliability model and equipments maintainability model,putforward to maintainability feature parameter and reliability feature parameter,andproceedresearchonrepair-timedistribution,parameterestimation,theequipmentsbreakdownintervaltimeK-Sexamination.In the fuzzy syntheses judgement method research of equipment maintenancedecision-making in the production line, fuzzy distribution of equipment can beestablished. Based on MTBF,MTTR,failure times etc. of equipment in theproduction line, using fuzzy set theory, equipment reliability diagnostic fuzzymathematics means is brought up, and meantime the research of time fuzzysyntheses judgementofequipment reliabilityis developed,andreliabilitydegreeofkey equipment in the engine cylinder production line is calculated. Equipmentreliability level is divided by using fuzzy syntheses judgement methods andrelevantmaintenancedecision-makingpolicyisbroughtup.In the extension analysis research of the production line equipmentmaintenancedecision-makingmethods,thematter-elementmodelofthe equipmentimportance degree grading are determined, and the equipment for multipleindicator parameters are assessed. It can also establish the grading related functionof equipment, and calculate the integrated equipment related degrees and gradingvariables identityvaluej *.Usingalargenumber ofrawdataterms tocalculatetherationindex in the assessing process of analysis, it can reduce the loss of precisionwhich is often from other evaluation methods, and manage the transformation ofthe qualitative and quantitative index of the quality and quantity. As a result, itgains a pretty logical appraise, and give a frame of reference for maintenanceactivitiesofcorporations.On the foundation of the reliability evaluation and of the production lineequipments, the computer assistance to maintenance management system has beendeveloped accordingto the production line. That system allows multi-user with thedifferent legal power to log, and adopts Client/Server mode. It have functionsincluding data collections management, making preventive maintenance decision,the data statistics, and the customer management etc. It helps to provide a validsupportterraceforequipmentmaintenancedecision-making.This research connected with real objects, having stronger pertinence thanbefore. Fuzzy reliability degree functions and matter-element model aboutimportance degree grade are put forward in the research, which has certaininnovation. From the reliability, maintainability, the model is established andanalysed according the production line equipment. The development of computerassistance to maintenance management system is helpful to the equipmentmaintenanceactivities.The maintenance management of the equipment is a complicated systemengineering, it involves being in extensive range, not merely correlated withmaintaining with the systematic own structure of the equipment, reliability andmaintainability of the system, and organizing system, market supply of themaintenance spare part, the maintenance personal level of maintenance are closelyrelated with.This text only goes on research of maintain equipment itself, a largenumber of questions will need to be studied further in the future. This textpreliminaryresearches onequipment maintenancedecisionaredoneinthis paper.Itneeds further research and development in the systematic model base and methodstorehousesoastoimproveitscommonabilityandpracticability.