工业工程专业英语

Unit6NextGenerationFactoryLayoutsBy谢文东、胡恒、陈小松、郑倩、凌丽•Thereisanemergingconsensusthatexistinglayoutconfigurationsdonotmeettheneedsofmultiproductenterprisesandthereisaneedforanewgenerationoffactorylayoutsthataremoreflexible,modular,andeasytoreconfigure.现在存在新的共识，那就是现有的工厂布局构造并不能满足多产品企业的需求而且更灵活、更模块化的和较容易重构的新一代工厂布局是急需的。•Withincreasedflexibility,modularity,andreconfigurability,factoriescouldavoidredesigningtheirlayoutseachtimetheirproductionrequirementschanged.Creatingnewlayoutscanbeexpensiveanddisruptive,especiallywhenfactoriesmustshutdown.因为有了更好的灵活性、模块化和可重构性，工厂每次在他们的产品要求改变的时候就避免了重新设计布局。特别当工厂必须关闭的时候，构造新的布局是昂贵的并对原有布局是具有破坏性的。•Becausefactoriesthatoperateinvolatileenvironmentsorintroducenewproductsregularlycannotaffordfrequentdisruptions,plantmanagersoftenprefertolivewiththeinefficienciesofexistinglayoutsratherthansufferthroughcostlyredesigns,whichmayquicklybecomesobsolete.由于那些在易变环境中经营和经常引进产品的工厂不能承受频繁的破坏，工厂管理者一般宁愿忍受现有布局的低效也不会去花重金重新设计那些很快就会过时的布局。•Conventionallayouts,suchasproduct,process,andcellularlayouts,donotmeettheseneeds.Theyaretypicallydesignedforaspecificproductmixandproductionvolumethatisassumedtocontinueforasufficientlylongperiod(usually,threetofiveyears).常规布局，比如产品、过程和一些由许多小单元组成的布局，不能满足这些需求。它们通常是为某一特定的产品结构和预计能持续足够长时间（通常为3到5年）的批量生产设计的。•Theevaluationcriterionusedinmostlayoutdesignprocedures—long-termmaterial-handlingefficiency——failstocapturetheprioritiesoftheflexiblefactory(forexample,scopeismoreimportantthanscale,responsivenessismoreimportantthancost,andreconfigurabilityismoreimportantthanefficiency).长期的物料装卸效率，一个曾经在绝大多数布局设计程序里使用的评价标准，没能占据灵活工厂的优先权（例如，机会比规模更重要，响应性比成本更重要，可重构性比效率更重要）。•Consequently,layoutperformancedeterioratesasproductvolumes,mix,orroutingsfluctuate.Astaticmeasureofmaterial-handlingefficiencyalsofailstocapturetheimpactoflayoutconfigurationonaspectsofoperationalperformance,suchaswork-in-processaccumulation,queuetimesatprocessingdepartments,andthroughputrates.因此，工厂布局将随着产品体积、结构或者线路的波动而恶化。而且物料装卸效率的静态测量也没能在在制品的累积、处理部门的排队时间和生产率等使用性能方面影响工厂布局的重构。•Consequently,layoutsthatimprovematerialhandlingoftencauseinefficiencieselsewhereintheformoflongleadtimesorlargein-processinventories.因此，那些能改善物料装卸的工厂布局总能在别处以长久的交货时间和大型制品存货的形式造成生产效率低下。•Whenproductvarietyishighorproductionvolumesaresmall,afunctionallayout,withallresourcesofthesametypeinonelocation,isoftenthoughttoprovidethegreatestflexible.当产品种类多或者产量小的时候，一个在一处有同一类型的所有资源的功能性布局，通常被认为能提供更好的灵活性（见表一）。•However,afunctionallayoutisnotoriousforitsmaterial-handlinginefficiencyandschedulingcomplexity,whichcanleadtolongleadtimes,largework-in-processinventories,andinefficientmaterialhandling.然而，它却因本身物料装卸效率低下和能造成更长的交货时间、大型制品存货和低效的物料装卸的调度复杂性而臭名昭著。•Whilegroupingresourcesbasedonfunctionprovidessomeeconomiesofscaleandsimplicityinallocatingworkloads,itmakesthelayoutsusceptibletomanufacturinginefficiencieswhentherearechangesinproductmixorroutings.Suchchangesoftenrequireacostlyredesignoftheplantlayoutorthematerial-handlingsystem.尽管根据功能对资源分组能提供一些规模经济和简单的工作量分配，但它也使工厂布局在产品结构和路线出现变化的时候更易受生产效率低下的影响。这些变化往往需要对工厂布局或物料装卸系统做个昂贵的再设计。•Analternativetoafunctionallayoutisacellularconfiguration,inwhichthefactoryispartitionedintocells,eachdedicatedtoafamilyofproductswithsimilarprocessingrequirements.替代功能性布局的是一个工厂能在其中被分为若干单元，而每一个单元又为有相似工序要求的产品系列专用的细胞结构。•Althoughcellularfactoriescansimplifyworkflowandreducematerialhandling,theyaregenerallydesignedtoproduceaspecificsetofproductswhosedemandlevelsareassumedtobestableandproductlifecyclessufficientlylong.尽管细胞工厂能简化工作流程、减少物料装卸，他们也通常是用来生产理想中需求层次稳定、生命周期足够长的特定系列的产品。•Infact,cellsareusuallydedicatedtosingleproductfamilieswithlittleallowanceforintercellflows.Cellularfactoriesareinefficientwhendemandforexistingproductsfluctuatesornewproductsareintroducedoften.事实上，细胞通常是致力于注液电池流程津贴少的单个产品系列。当现有产品需求波动时或新产品经常被引进，单元化工厂就很低效。•Someauthorshaveproposedalternativecellularstructurestoovercometheseproblems,suchasoverlappingcells,cellswithmachinesharing,andfractalcells.Althoughanimprovement,thesealternativesremainboundedbytheircellularstructure.一些作者提出了可供选择的细胞结构去克服这些问题，如重叠单元、机器共享单元和分形体单元。虽然有了改善，但由于它们的细胞结构，这些替代物仍是有界的。布局设计程序,无论是功能或细胞的布局,大部分已经都基于确定性的范例。这样的设计参数,如产品结构、产品的需求,产品线路被认为是确知的。•Layoutdesignprocedures，whetherforfunctionalorcellularlayouts，havebeenlargelybasedonadeterministicparadigm.Suchdesignparametersasproductmix,productdemands,andproductroutingsareassumedtobeknownwithcertainty.设计标准往往是一个静态的效率来源(总共邻接得分效率,总成本,或者两者的结合),它不需要弹性和捕获可重构性。•Thedesigncriterionisoftenastaticmeasureofmaterial-handlingefficiency(atotaladjacencyscore,totalmaterial-handlingcost,oracombinationofboth),whichdoesnotcapturetheneedforflexibilityandreconfigurability.事实上,人们对布局的灵活性和性能之间的关系知之甚少,评价分析模型亦不足。同时，影响对布局结构性能的弹性也不能很好的理解。当期设计标准不考虑影响布局效果的阻塞、周期时间、吞吐率等指标作为。•Infact,therelationshipbetweenlayoutflexibilityandlayoutperformanceispoorlyunderstoodandanalyticalmodelsforitsevaluationarelacking.Thestructuralpropertiesoflayoutsthataffecttheirflexibilityarealsonotwellunderstood.Currentdesigncriteriadonotcapturetheeffectoflayoutonsuchperformancemeasuresascongestion,cycletime,andthroughputrate.他们也忽略了在工作场所中诸如设置、配料和装卸等操作参数的影响,更重要的是，他们