Bài giảng môn Quản trị kinh doanh - Chapter 9: Manufacturing planning and control

Manufacturing Planning and ControlMPC 6th EditionChapter 9Just-in-TimeJust-in-time (JIT) approaches to manufacturing planning and control change both manufacturing practices and MPC execution.JIT reduces the complexity of detailed material planning, the need for shop-floor tracking, work-in-process inventories, and the transactions associated with shop-floor and purchasing systems.AgendaJust-in-Time in Manufacturing Planning & ControlResourceplanningSales and operationsplanningDemandmanagementMaster productionschedulingDetailed materialplanningMaterial andcapacity plansShop-floorsystemsSuppliersystemsDetailed capacityplanningJIT impacts most MPC systemsJIT ElementsJIT Action ProgramsReduced setup times and lot sizes“No defects” goalImproved quality through process improvementTotal productive maintenance (TPM)Poka-yoke–foolproof operationsContinuous improvementWorker involvementCellular manufacturingJIT BenefitsReduced throughput timeShorter material movement distancesFewer material movementsReduced transactionsSimplified MPCReduced changeover timesGreater market responsivenessInventory reductionsLabor cost reductionsMore satisfied/cohesive workersBetter team workSpace reductionsQuality cost reductionsQuality improvementsThe Hidden FactoryThe hidden factory processes transactionsJIT Building BlocksProduct designProcess designManufacturing planning and controlHuman/organizational elementsJITJIT ExampleMultiple models with unique parts and widely varying forecasts200,000 basic2,500 clad25,000 basic100,000 cladLeveling the ProductionPlan a level output of each modelProduction of each model during each day (or suitable short interval)Full-mix production reduces inventory build-upConvert annual forecasts to daily requirementsDifferences between requirements and current lot sizes drives setup time reductionPull System IntroductionA pull system authorizes a work center to produce only when there is a downstream needWork centers don’t produce just to keep workers busyProduction in response to a signalVerbal request, empty container, kanban cards, etc.Daily Production and Current Lot Size MismatchesPan ModelHandleMetalAnnual ForecastDaily ForecastLot Size151ABasicSheet200,0008008,000151BBasicClad2,50010900151CExecutiveSheet25,0001003,000151DExecutiveClad100,0004006,000Lot sizes cover 10 to 90 days usage!Product Redesign for JITCommon handle with variable gripSimplified handle design reduces inventory items and number of operationsProcess Design for JITProduct redesign allows rethinking factory layoutCellular manufacturing with visible inventory management, less inventory, and shorter product flow distancesPull System Inventory Control2 full containers signal handle assembly to stop workingFinal assembly consumes stock until container is emptyEmpty container returned, signaling handle assembly to begin workingFinal assembly uses second container while first is refilledFull container is returned to final assembly for useJIT ApplicationsSingle-card kanban systemA card is attached to each container of finished parts. When the parts are moved to the next processing center, the card is returned to the supplying center to authorize more production.Each container has a kanban card, the number of cards controls the inventory levelsNon-Repetitive JITJIT originated in high-volume repetitive manufacturing situationsMany principles can be applied to low-volume settingsTwo key problems ariseRequirement of setting up high-volume flow lines dedicated to a few productsLevel loadingService-Enhanced JITJIT objective of accepting any customer order and producing it behind any other order remains keyFlexibility to handle large surges in volume or mix changes is also importantFlexible systems can enhance JITProduct design, manufacturing flexibility, and worker cross-training are keysJoint-Firm JITWhen properly implemented, JIT can facilitate relationships with suppliers and improve both firm’s competitiveness.Poorly implemented, suppliers are often asked to buffer inaccurate schedules.A number of basic requirements existA stable scheduleReduced supplier baseJIT CouplingTightly CoupledSuppliers build to an exact sequenceParts are not held in inventory at the supplier or the manufacturerInventory transactions are unnecessary, supplier is paid based on manufacturer productionRequires flawless execution by both firmsLess Tightly CoupledSupplier has more customersCustomer has multiple suppliersGoods are delivered according to a scheduleSome goods are held in inventory at supplier and/or manufacturerUseful when uncertainty is higherJIT HubsSuppliers place goods in an inventory location that is physically close to the customerSupplier and customer can eliminate their inventoriesVisibility of hub inventory is available to both supplier and customerSupplier needs knowledge of customer’s expected usageSupplier has flexibility in how to meet demandJIT SoftwareOverallPlatformMRP SystemsJIT SystemsCommon Systems (both MRP and JIT)PrinciplesStabilizing (or leveling) the production schedule is a prerequisite to effective JIT systems.Achieving very short lead times supports better customer service and responsiveness.Reducing hidden factory costs can be as important as reducing more visible costs.Implementing the “whole person” concept reduces distinctions between white- and blue-collar workers and taps all person’s skills for improving performance.PrinciplesCost accounting and performance measures need to reflect the shift in emphasis associated with JIT.To achieve JIT’s benefits in a non-repetitive application, some basic features of repetitive-based JIT must be modified.JIT is not incompatible with MRP systems. With an incremental approach, MRP firms can adopt as much or as little of JIT as they desire.Quiz – Chapter 9JIT replaces discrete manufacturing batches with ____________ ___________ goals.Under JIT, the objective is to reduce _________, __________, and ______________.Transactions required to track materials, verify activities, ensure quality, and manage changes are referred to as the ___________ factory.JIT is likely to utilize a push scheduling system? (True/False)A kanban system is used to manage ___________ transactions.JIT adoption may require a change in measurement and reward systems? (True/False)