Bài giảng Operations Management - Chapter 14: JIT and Lean Operations

JIT and LeanOperationsMcGraw-Hill/Irwin Copyright © 2012 by The McGraw-Hill Companies, Inc. All rights reserved.You should be able to:Explain what is meant by the term lean operations systemList each of the goals of a lean system and explain its importanceList and briefly describe the building blocks of leanList the benefits of a lean systemOutline the considerations important in converting a traditional mode of operations to a lean systemPoint out some of the obstacles that might be encountered when converting to a lean systemDescribe value stream mappingStudent Slides14-*Lean operationA flexible system of operation that uses considerably less resources than a traditional systemTend to achieveGreater productivityLower costsShorter cycle timesHigher qualityStudent Slides14-*The ultimate goal:Achieve a system that matches supply to customer demand; supply is synchronized to meet customer demand in a smooth uninterrupted flowA balanced systemOne that achieves a smooth, rapid flow of materials and/or work through the system14-*Student SlidesStudent Slides14-*The degree to which lean’s ultimate goal is achieved depends upon how well its supporting goals are achieved:Eliminate disruptionsMake the system flexibleEliminate waste, especially excess inventoryStudent Slides14-*Product designProcess designPersonnel/organizational elementsManufacturing planning and controlStudent Slides14-*Five personnel/organizational elements that are important for lean systems:Workers as assetsCross-trained workersContinuous improvementCost accountingLeadership/project managementStudent Slides14-*Seven elements of manufacturing planning and control (MPC) are particularly important for lean system:Level loadingPull systemsVisual systemsLimited work-in-process (WIP)Close vendor relationshipsReduced transaction processingPreventive maintenance and housekeeping14-*Student SlidesPush systemWork is pushed to the next station as it is completedPull systemA workstation pulls output from the preceding workstation as it is neededOutput of the final operation is pulled by customer demand or the master schedulePull systems are not appropriate for all operationsLarge variations in volume, product mix, or product design will undermine the system14-*Student SlidesKanban Card or other device that communicates demand for work or materials from the preceding stationKanban is the Japanese word meaning “signal” or “visible record”Paperless production control systemAuthority to pull, or produce, comes from a downstream process.Two main types of kanbans:Production kanban (p-kanban): signals the need to produce partsConveyance kanban (c-kanban): signals the need to deliver parts to the next work center.14-*Student SlidesIdeal number of kanban cards14-*Student SlidesMake sure top management is committed and that they know what will be requiredDecide which parts will need the most effort to convertObtain support and cooperation of workersBegin by trying to reduce setup times while maintaining the current systemGradually convert operations, begin at the end and work backwardsConvert suppliers to JITPrepare for obstacles14-*Student SlidesManagement may not be fully committed or willing to devote the necessary resources to conversionWorkers/management may not be cooperativeIt can be difficult to change the organizational culture to one consistent with the lean philosophySuppliers may resist Student Slides14-*Be careful to study the requirements and benefits of lean systems before making a decision to convert operationsEvaluate strengths and weaknesses of current operationsThe decision to convert can be sequentialWeigh the pros and cons of a lean approach to inventoriesSupplier management is critical to a lean operationStudent Slides14-*