采购与仓储管理-Warehouse science

WarehouseScience颜涛浙江财经学院工商管理学院物流教研室E-mail:[e-mail]13656633908第一章Warehouserationale仓库是什么？Warehousesarethepointsinthesupplychainwhereproductpauses,howeverbriefly,andistouched.为什么需要仓库？Tobettermatchsupplywithcustomerdemand:demandcanchangequickly,butsupplytakeslongertochange.Warehousescanalsobufferagainstsuddenchangesinsupply.ToconsolidateproductToprovidevalue-addedprocessing仓库分类Whiletherearemanytypesofwarehousesinthesupplychain,thereisasystematicwaytothinkaboutawarehousesystemregardlessoftheindustryinwhichitoperates.第一章Warehouserationale第二章Materialflow什么是供应链？The“supplychain”isthesequenceofprocessesthroughwhichproductmovesfromitsorigintowardthecustomer.Pipeline与incompressiblefluidmodel流体模型流体模型对我们的启发:Keeptheproductmoving;avoidstartsandstops,whichmeanextrahandlingandadditionalspacerequirements.Avoidlayoutsthatimpedesmoothflow.Identifyandresolvebottleneckstoflow.流体模型与JIT的关系该模型是对现实的一种近似第二章Materialflow库位固定库位：Thesimplestisdedicatedstorage,inwhicheachlocationisreservedforanassignedproductandonlythatproductmaybestoredthere.固定库位的好处（Pros）Becausethelocationsofproductsdonotchange,morepopularitemscanbestoredinmoreconvenientlocationsandworkerscanlearnthelayout,allofwhichmakesorder-pickingmoreefficient.第二章Materialflow库位：固定库位与共享库位Storage:“Dedicated”versus“Shared”固定库位的缺点（Cons)：Theproblemwithdedicatedstorageisthatitdoesnotusespaceefficiently.共享库位第二章Materialflow库位：固定库位与共享库位Storage:“Dedicated”versus“Shared”共享库位的缺点：需要仓库管理信息系统的支持工人操作时间成本及复杂性增加怎么办？第二章Materialflow库位：固定库位与共享库位Storage:“Dedicated”versus“Shared”共享库位对提高仓库存储空间利用率的测算Howmuchimprovementinspaceutilizationispossiblewithsharedstorage?考虑一种产品，两周的需求量，存储在两个相等大小的库位上且需求速率恒定的情形空间利用率=平均库存/平均所需存储空间第二章Materialflow库位：固定库位与共享库位Storage:“Dedicated”versus“Shared”第三章：仓库作业Warehouseoperations仓库作业的总体特点：Awarehousereorganizesandrepackagesproduct.Producttypicallyarrivespackagedonalargerscaleandleavespackagedonasmallerscale.Inotherwords,animportantfunctionofthiswarehouseistobreakdownlargechunksofproductandredistributeitinsmallerquantities.Ingeneral,thesmallerthehandlingunit,thegreaterthehandlingcost.仓库作业具体而言，包括以下两大部分：InboundprocessesReceiving收货Put-away放置OutboundprocessesOrder-picking分拣Checking,packing,shipping第三章：仓库作业Warehouseoperations仓库作业的原则尽可能减少停顿保持可视化第三章：仓库作业WarehouseoperationsReceiving（收货）作业的特点Receivingmaybeginwithadvancenotificationofthearrivalofgoods.Thisallowsthewarehousetoschedulereceiptandunloadingtocoordinateefficientlywithotheractivitieswithinthewarehouse.伴随接收的可能有检验,扫描输入数据库等.人力需求不高对配送中心而言，大约仅占其运作成本的10%左右第三章：仓库作业WarehouseoperationsPut-away（放置）作业在物品摆放到货架之前，必须决定好其合适的存储地点并将该信息输入系统需要较多的人力成本对配送中心而言，大约仅占其运作成本的15%左右第三章：仓库作业WarehouseoperationsOrder-picking分拣与其它作业相比，与信息系统的结合更紧密Order-picking与收货不同,前者是被动的少量的.而后者是可能事先知道故做了相关准备且是大批的.故前者更费时间.另外,随着生命周期越来越短,对拣货的时间要求越来越快.第三章：仓库作业Warehouseoperations分拣大约仅占仓库运作成本的55%左右，分拣成本进一步可分解为以下各部分第三章：仓库作业WarehouseoperationsOrder-picking对不同物品的分拣成本是不同的。提高分拣效率的方法storingthemostpopularskustogetherbatchorders合并订单进行分拣第三章：仓库作业Warehouseoperations是否应合并订单进行分拣取决于订单结构single-lineordersVerylargeordersIntermediate-sizeorders注意,BatchingPicking可能会减少Responsiveness,因为还需再次分拣第三章：仓库作业Warehouseoperations分拣的其它问题分拣工人的合作分拣问题可分为product-to-picker与Picker-to-product第三章：仓库作业WarehouseoperationsCheckingandpacking对人力需求大LittleWalking保证订单准确性，避免错发货对客户的订单尽可能提高包装的容积率第三章：仓库作业Warehouseoperations总结Mostoftheexpenseinatypicalwarehouseisinlabor;mostofthatisinorder-picking;andmostofthatisintravel.仓库的其它作业handlereturnslabelingPostponementoffinalassemblyInvoicing第三章：仓库作业Warehouseoperations确定仓库需要的月台（DOCK）的数量nD=dt/qT仓库容量的决定(以托盘的数量为计算单位)1:Dedicatedstoragepolicy2:Randomstoragepolicy3:Class-basedstoragepolicy计算实例计算储存区的长宽高高是由储存的技术来决定的(如叉车最高能多高,如是人力的话最高能多高)长与宽的决定LxLyNxNy计算实例第六章仓储规划确定仓库需要的月台（泊位）数量确定仓库需要的月台（泊位）数量仓库容量的决定Theareaofthestoragezonemustbelargeenoughtoaccommodategoodsinpeakperiods.Ontheotherhand,ifthestoragezoneexceedstherealneedsofthefirm,storageandretrievaltimesbecomeuselesslyhigh.Thiscouldreducethethroughputorincreasematerialhandlingcost.计算储存区的长宽高计算储存区的长宽高计算储存区的长宽高计算储存区的长宽高计算储存区的长宽高计算储存区的长宽高第六章仓库内部规划因而，为了最小化行走成本（Travelcost):将所有的库位按照di从小到大进行排序将所有的物品按周转速度从大到小进行排序Movedownthelist,assigningthepalletsofthenextfastest-turningskustothenextbestlocationsavailable.第六章仓库内部规划第六章仓库内部规划--确定收货与发货区的位置第六章仓库内部规划--确定收货与发货区的位置哪种更好?取决于流入流出仓库物品的总体结构Iftherewillbeasmallamountofveryfast-movingskus,itmaybemoreefficienttoputreceivingandshippingonthesamesideofthefacility,becausethesavingsfromthefewveryconvenientlocationsmayoffsetanylossduetothegreaternumberoflessconvenientlocations.第六章仓库内部规划第一种：贯通式Flow-throughconfiguration这两种规划各自的特点characteristicsofeachtypeoflayout:第一种：贯通式收发货区位于仓库的两侧使得很多存储库位处于同等便利的位置保守设计:Morereasonablyconvenientstoragelocations但很少的库位处于非常便利的位置更适合于流量非常大的仓库适合于仓库长而狭窄时的情形Limitsopportunityforefficienciesbydualtransactions两种规划各自的特点第二种：U-形设计这两种规划各自的特点characteristicsofeachtypeoflayout:第二种：U-形设计收发货区位于库房的同侧Makesthemostconvenientlocationsstillmoreconvenient,lessconvenientlocationsevenworse.适合于当物品的周转速度呈现较强的ABC特点时的情形提高了