Lean Manufacturing & Just-in-Time"The most dangerous kind of waste is the waste we do not recognize." - Shigeo Shingo

Reducing Waste: Push versus Pull System

Push SystemEvery worker maximizes own output, making as many products as possiblePros and cons:Focuses on keeping individual operators and workstations busy rather than efficient use of materialsVolumes of defective work may be producedThroughput time will increase as work-in-process increases (Littles Law)Line bottlenecks and inventories of unfinished products will occurHard to respond to special orders and order changes due to long throughput time

Pull SystemProduction line is controlled by the last operation, Kanban cards control WIPPros and consControls maximum WIP and eliminates WIP accumulating at bottlenecksKeeps materials busy, not operators. Operators work only when there is a signal to produce.If a problem arises, there is no slack in the systemThroughput time and WIP are decreased, faster reaction to defects and less opportunity to create defects

*Features of Lean Production

A Little History!Ford: Design for manufacturingStart with an article that suits and then study to find some way of eliminating the entirely useless parts. This applies to everything a shoe, a dress, a house, a piece of machinery, a railroad, a steamship, an airplane. As we cut out useless parts and simplify necessary ones, we also cut down the cost of making. ...But also it is to be remembered that all the parts are designed so that they can be most easily made."

A Little History!Ohno put ideas into practice systematicallyWhen bombarded with questions from our group on what inspired his thinking, Ohno just laughed and said he learned it all from Henry Ford's book."

A system that continually searches for and eliminates waste throughout the value chain.

Views every enterprise activity as an operation and applies its waste reduction concepts to each activity - from Customers to the Board of Directors to Support Staff to Production Plants to Suppliers.TPS: Toyota Production System

Elimination of WasteComplexityLaborOverproductionSpaceEnergyDefectsMudaMaterialsInventoryTimeTransportationAcronym CLOSED MITT

*5SGroup technology Quality at the sourceJIT productionKanban production control system Minimized setup times Uniform plant loadingFocused factory networks

Elimination of Waste

Minimizing Waste 5SGood factories develop beginning with the 5Ss. Bad factories fall apart beginning with the 5 Ss.- Hirouki Hirano

JapaneseTranslationEnglishSeiriProper arrangementSortSeitonOrderlinessSimplifySeisoCleanlinessSweepSeiketsuCleanupStandardizeShitsukeDisciplineSustain

Minimizing Waste 5SA place for everything and everything in its placeNot just a housekeeping issueCritical foundation forSetup reductionPull systemsMaintenanceInventory management

Using Departmental Specialization (Job Shop) for plant layout can cause a lot of unnecessary material movement SawSawLathePressPressGrinderLatheLatheSawPressHeat TreatGrinderNote how the flow lines are going back and forthMinimizing Waste: Group Technology

PressLatheGrinderGrinderA2BSawHeat TreatLatheSawLathePressLathe1Revising by using Group Technology Cells can reduce movement and improve product flow Minimizing Waste: Group Technology

Minimizing Waste: JITOnly produce whats neededThe opposite of Just In Case philosophyIdeal lot size is oneMinimize transit timeFrequent small deliveriesProsMinimal inventoryLess spaceMore visualEasier to spot quality issuesCons Requires disciplineRequires good problem solvingSuppliers or warehouses must be closeRequires high quality???

*Inventory Hides ProblemsMinimizing Waste: JIT

Minimizing Waste Quality at the SourceDo it right the first timeCall for helpImmediately stop the process and correct it vs. passing it on to inspection or repairAndon

Jidoka

Minimizing Waste KanbanSignaling device to control flow of materialCardsEmpty containersLightsColored golf ballsEtc

Minimizing Waste Setup TimesLong setup times drive:Long production runsLarge lotsLong lead timesJIT requires small lots and minimum kanbansSetup reductionFocused effortsProblem solvingFlexible equipment

*Not uniformJan. UnitsFeb. UnitsMar. UnitsTotal1,2003,5004,3009,000UniformJan. UnitsFeb. UnitsMar. UnitsTotal3,0003,0003,0009,000Suppose we operate a production plant that produces a single product. The schedule of production for this product could be accomplished using either of the two plant loading schedules below. How does the uniform loading help save labor costs? or Minimizing Waste Plant LoadingHeijunka

CoordinationSystem IntegrationThese are small specialized plants that limit the range of products produced (sometimes only one type of product for an entire facility)Minimizing Waste Focused Factory Networks

Level payrollsCooperative employee unionsSubcontractor networksBottom-up management styleQuality circles (Small Group Problem Solving)TPS Respect for PeopleKeiretsu

All work shall be highly specified as to content, sequence, timing, and outcomeEvery customer-supplier connection must be direct, and there must be an unambiguous yes-or-no way to send requests and receive responsesThe pathway for every product and service must be simple and directAny improvement must be made in accordance with the scientific method, under the guidance of a teacher, at the lowest possible level in the organization TPS 4 Rules

Lean ImplementationEmpowered WorkforceProblem SolvingPerformance MeasurementTotal QualityManagementFlowProcessStableScheduleKanbanPullInvolvedSuppliersContinual InventoryReductionProductDesign

Summary and ConclusionsLean Production is the set of activities that achieves quality production at minimum cost and inventoryThe flow of material is pulled through the process by downstream operationsLean originated with the Toyota Production System and its two philosophies elimination of waste, and respect for peopleCLOSED MITT forms of waste

13689141272121