Presentation on theme: "Lean operations and JIT"— Presentation transcript:
1 Lean operations and JIT Chapter 15Lean operations and JITSource: Tibbet and Britten
2 Lean operations and JIT Operations strategyLean operations and JITThe market requires … specified time, quantity and quality of products and servicesOperations managementDesignImprovementThe operation supplies … the delivery of products and services only when neededPlanning and control
3 ‘The key principle of lean operations is relatively straightforward to understand: it means moving towards the elimination of all waste in order to develop an operation that is faster and more dependable, produces higher quality products and services and, above all, operates at low cost.’
4 Synonyms continuous flow manufacture high value-added manufacture stockless productionlow-inventory productionfast-throughput manufacturinglean manufacturingToyota production systemshort cycle time manufacturingSource: Corbis/Denis Balihouse
5 JIT material flow Traditional approach JIT approach buffer inventory stage Astage Bstage CJIT approachordersordersstage Astage Cstage Bdeliveriesdeliveries
6 JIT and capacity utilization JIT approachfocus on producing only when neededfewer stoppageslow inventory so problems are exposed and solvedno surplus production goes into inventorylower capacity utilization, butJIT and capacity utilizationTraditional approachfocus on high capacity utilizationmore stoppages because of problemshigh inventory means less chance of problems being exposed and solvedextra productiongoes into inventory because of continuing stoppages at stagesmore production at each stage
7 JIT definitionsJIT aims to meet demand instantly, with perfect quality and no wasteMore fully:Improved overall productivity and elimination of wasteCost-effective production and delivery of only the necessary quantity of parts at the right quality, at the right time and place, while using a minimum amount of facilities, equipment, materials and human resourcesJIT is dependent on the balance between the supplier’s flexibility and the user’s flexibilityJIT is accomplished through the application of elements that require total employee involvement and teamworkSource: EmpicsA key philosophy of JIT is simplification
8 The lean philosophy of operations is the basis for JIT techniques that include JIT methods of planning and controlThe lean philosophy of operationsEliminate wasteInvolve everyoneContinuous improvementJIT as a set of techniques for managing operationsBasic working practicesDesign for manufactureOperations focusSmall, simple machinesFlow layoutTPMSet-up reductionTotal people involvementVisibilityJIT supplyJIT as a method of planning and controlPull scheduling‘Kanban’ controlLevelled schedulingMixed modellingSynchronization
9 The 5 S’sSort (Seiri) Eliminate what is not needed and keep what is needed.Straighten (Seiton) Position things in such a way that they can be easily reached whenever they are needed.Shine (Seiso) Keep things clean and tidy; no refuse or dirt in the work area.Standardize (Seiketsu) Maintain cleanliness and order – perpetual neatness.Sustain (Shitsuke) Develop a commitment and pride in keeping to standards.
10 Delivering smaller quantities more often can reduce inventory levels
11 influencing the throughput efficiency Waste (muda)Which of these symbols signify non-value- adding activities?Activities:Types of waste:operationover-productionwaiting timemovementtransportinspectionprocessinventorydelaymotionstoragedefective goodsinfluencing the throughput efficiency
12 The problem with inventory Reduce the level of inventory (water) to reveal the operations’ problemsWIPDefective materialsproductivity problemsScrapReworkDowntimeWIPDefective materialsReworkScrapDowntimeproductivity problems
13 Small machinesThe conventional Western approach is to purchase large machines to get ‘economies of scale’.These often have long, complex set-ups, and make big batches, quickly creating ‘waste’.
14 Using several small machines rather than one large one allows simultaneous processing, is more robust and is more flexibleJIT small machines approach:easy to move (layout)quick set-upflexible scheduling optionscheaper toolingfewer set-ups neededplanned maintenance easieremphasis:flexibilityeconomies of scope
15 Visible, enforced improvement ‘Traditional’ production systems often accept waste and use the insurance of all types of inventoryIn JIT systems:gradual reduction of inventoryidentify exposed problemseliminate these problemsrepeat the cycleemphasis:continuous improvement in small steps, to expose waste and eliminate it
17 Key Terms Test Just-in-time (JIT) A method of planning and control and an operations philosophy that aims to meet demand instantaneously with perfect quality and no waste.KaizenJapanese term for continuous improvement.Set-up reductionThe process of reducing the time taken to change over a process from one activity to the next; also called single minute exchange of dies (SMED) after its origins in the metal pressing industry.
18 Key Terms Test Single minute exchange of dies (SMED) Alternative term for set-up reduction.AndonA light above a workstation that indicates its state: whether working, waiting for work, broken down, etc. Andon lights may be used to stop the whole line when one station stops.
19 Key Terms TestKanbanJapanese term for card or signal; it is a simple controlling device that is used to authorize the release of materials in pull control systems such as those used in JIT.Levelled scheduling (Heijunka)The idea that the mix and volume of activity should even out over time so as to make output routine and regular, sometimes known by the Japanese term ‘heijunka’.