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Lean manufacturing, sản xuất
lean manufacturing system lean manufacturing system Toyota Production systems Toyota Production systems ( TPS ) ( TPS ) Prepared by : Hassan Omar Badkook 2009 What is lean manufacturing? What is lean manufacturing? Definitions : Definitions : ► ► LM is a set of tools and methodologies that aims for the conti LM is a set of tools and methodologies that aims for the conti nuous nuous elimination of all waste in the production process. elimination of all waste in the production process. ► ► a system approach to identifying and eliminating waste (non a system approach to identifying and eliminating waste (non - - value added value added activities) through continuous improvement by flowing the p activities) through continuous improvement by flowing the p roduct at roduct at the pull of the customer in pursuit of perfection the pull of the customer in pursuit of perfection - - The main benefits of LM are lower production costs , increased The main benefits of LM are lower production costs , increased output and shorter output and shorter production lead times. production lead times. Key principles of lean manufacturing Key principles of lean manufacturing 1 1 - - Recognition of waste: Recognition of waste: - - The first step is to recognize what does and does not create va The first step is to recognize what does and does not create va lue from the lue from the customer customer ’ ’ s perspective. s perspective. - - Any material , process or feature which is not required for cre Any material , process or feature which is not required for cre ating value from the ating value from the customer customer ’ ’ s perspective is waste and should be eliminated s perspective is waste and should be eliminated 2 2 - - Standard processes : Standard processes : - - Lean requires an the implementation of very detailed production Lean requires an the implementation of very detailed production guidelines, called guidelines, called (standard work) (standard work) - - Clearly state the content , sequence , timing and outcome of a Clearly state the content , sequence , timing and outcome of a ll actions by workers. ll actions by workers. - - This eliminate variation in the way that workers perform their This eliminate variation in the way that workers perform their tasks tasks 3 3 - - continuous flow : continuous flow : - - Lean aims to a continuous production flow free of bottlenecks, Lean aims to a continuous production flow free of bottlenecks, interruption interruption ,backflows or waiting. ,backflows or waiting. - - Production cycle time can be reduced by as much as 90% Production cycle time can be reduced by as much as 90% 4 4 - - pull pull - - production( also called Just production( also called Just - - in in - - time) time) - - Aims to produce only what is needed , when it is needed. Aims to produce only what is needed , when it is needed. - - Production is pulled by the downstream workstation so that each Production is pulled by the downstream workstation so that each workstation should only workstation should only produce what is requested by the next workstation. produce what is requested by the next workstation. Key principles of lean manufacturing Key principles of lean manufacturing 5 5 - - Quality at source: Quality at source: - - lean aims for lean aims for - - Defects to be eliminated at the source Defects to be eliminated at the source - - Quality inspection to be done by the workers as part of the in Quality inspection to be done by the workers as part of the in - - line production line production process. process. 6 6 - - Continuous improvement: Continuous improvement: - - Lean requires striving for perfection by continually removing l Lean requires striving for perfection by continually removing l ayers of waste as they ayers of waste as they are unconverted. are unconverted. - - This in turn requires a high level of worker involvement in the This in turn requires a high level of worker involvement in the continuous continuous improvement process. improvement process. History of lean manufacturing History of lean manufacturing Key implications of lean manufacturing Key implications of lean manufacturing Lean manufacturing Lean manufacturing Traditional batch Traditional batch manufacturing manufacturing Customer driven Customer driven Supply driven Supply driven Orientation Orientation Orders are pulled through factory Orders are pulled through factory based on customer/downstream based on customer/downstream demand demand Orders are pushed through factory Orders are pushed through factory based on production plan/forecast based on production plan/forecast Planning Planning Small Small large large Batch size Batch size In In - - line inspection by workers line inspection by workers Checking of samples by QC Checking of samples by QC inspectors inspectors Quality inspection Quality inspection Little or no work Little or no work - - in in - - progress progress between each production stage between each production stage Buffer of work Buffer of work - - in in - - progress between progress between each production stage each production stage Inventory Inventory Materials handed off directly from Materials handed off directly from one production stage to the next one production stage to the next Materials after each stage accumulate Materials after each stage accumulate into works into works - - in in - - progress storage areas progress storage areas before being retrieved by next before being retrieved by next production stage production stage Handoff of works Handoff of works - - in in - - process process Total production cycle shortens to Total production cycle shortens to approach time spent actually approach time spent actually processing the materials processing the materials Total production cycle takes Total production cycle takes significantly longer than actual time significantly longer than actual time spent processing the materials spent processing the materials Production cycle time Production cycle time Lean manufacturing goals Lean manufacturing goals ▪ ▪ Eliminate disruption Eliminate disruption ▪ ▪ Make system flexible by reduce setup and Make system flexible by reduce setup and lead times lead times ▪ ▪ Eliminate waste Eliminate waste ▪ ▪ Sources of waste ( non Sources of waste ( non - - value adding ) value adding ) ▪ ▪ Originally 7 main types of waste Originally 7 main types of waste - - Over Over - - production production - - Waiting time Waiting time - - Unnecessary transportation Unnecessary transportation - - Processing waste Processing waste - - Inefficient work methods Inefficient work methods ( Motion waste) ( Motion waste) - - Product defects Product defects - - Excess inventory Excess inventory Main kinds of waste Main kinds of waste ► ► Originally 7 main types of waste were identified as part of the Originally 7 main types of waste were identified as part of the Toyota Toyota Production System. Production System. ► ► This list has been modified and expanded by various practitioner This list has been modified and expanded by various practitioner s of lean s of lean manufacturing and generally includes the following : manufacturing and generally includes the following : 1 1 - - Over Over - - production waste: production waste: ▪ ▪ Unnecessarily producing more than demanded Unnecessarily producing more than demanded ▪ ▪ Producing it too early before it is needed Producing it too early before it is needed That will be: That will be: - - Increase the risk of obsolescence Increase the risk of obsolescence - - Increase the risk of producing the wrong thing Increase the risk of producing the wrong thing - - Increases the possibility of having to sell those items at a di Increases the possibility of having to sell those items at a di scount or discard them as scount or discard them as scrap. scrap. Main kinds of waste Main kinds of waste 2 2 - - Waiting waste: Waiting waste: ▪ ▪ Waiting is idle time for workers or machines due to bottlenecks Waiting is idle time for workers or machines due to bottlenecks or inefficient or inefficient production flow on the factory floor. production flow on the factory floor. ▪ ▪ Waiting also includes small delays between processing of units. Waiting also includes small delays between processing of units. Waiting results in Waiting results in a significant cost insofar as it increases labor costs and a significant cost insofar as it increases labor costs and depreciation costs per unit of output. depreciation costs per unit of output. 3 3 - - Transportation waste: Transportation waste: ▪ ▪ Transportation includes any movement of materials that does not Transportation includes any movement of materials that does not add any value to the add any value to the product, such as moving materials between workstations. product, such as moving materials between workstations. ▪ ▪ The idea is that transportation of materials between production The idea is that transportation of materials between production stages should aim for stages should aim for the ideal that the output of one process is immediately used the ideal that the output of one process is immediately used as the input for the as the input for the next process. next process. Transportation between processing stages results in Transportation between processing stages results in prolonging prolonging production cycle times , the inefficient use of labor and space production cycle times , the inefficient use of labor and space and can also be a and can also be a source minor production stoppages. source minor production stoppages. Main kinds of waste Main kinds of waste 4 4 - - over over - - processing: processing: ▪ ▪ Over Over - - processing is unintentionally doing more processing work than th processing is unintentionally doing more processing work than th e customer e customer requires in terms of product quality or features requires in terms of product quality or features – – such as polishing or applying such as polishing or applying finishing on some areas of a product that won't be seen by the c finishing on some areas of a product that won't be seen by the c ustomer ustomer 5 5 - - Motion waste: Motion waste: ▪ ▪ Motion includes any unnecessary physical motion or walking by w Motion includes any unnecessary physical motion or walking by w orkers which orkers which diverts them from actual processing work. diverts them from actual processing work. For example For example - - Include walking around the factory floor to look for a tool Include walking around the factory floor to look for a tool - - Difficult physical movements, due to poorly designed ergonomics Difficult physical movements, due to poorly designed ergonomics which slow which slow down the workers. down the workers. [...]... trial-and-error tests JIT /Lean production Just-in-time - A highly coordinated production system in which processing and movement of materials and goods occur just as they are needed (perfect timing), usually in small batches - Developed in Toyota® by Taiichi Ohno (Vice president of manufacturing) in the so-called Toyota Production System (TPS) - JIT is characteristic of lean production systems where... Lead Time 50% Raw Material Inventory 50% 82% Work-in-Process Inventory 0% 20% 40% 60% 80% 100% JIT /lean streamlines production Traditional Flow Production Process (stream of water) Suppliers Flow with JIT Suppliers Customers Inventory (stagnant ponds) Material (becomes like water in stream) Customers Lean manufacturing tools and methodology ►Standard work ►Communication of standard work to employees ►Standard... ►Batch size reduction ►Production Layout and point of use storage ►Kanban ►Production Leveling ►Pacemaker ►Overall Equipment Effectiveness Lean/ JIT Goals and Building Blocks Lean/ JIT Building Blocks 1- Product design 2- Process design 3- personnel/organization elements 4- manufacturing planning and control 1- product design ►standard parts - use of standard parts leads to : fewer parts - reduced training... costs ►modular design - Clusters of parts treated as a single unit- reduced unitassembly and handling costs ►quality - Quality built into the product and the processes ►concurrent engineering - Design and manufacturing work together early in the design stage (integrating production functions) 1.1 standardized parts 1.2 modular design Design modular components that can be configured into a wide variety of... Maintain current level Reduce energy level to 7.5 ft/lb 10 BA X Relationships: Strong = 9 Medium = 3 Small = 1 B 1.4 concurrent engineering 2 - Process design ►small batch size ►setup time reduction manufacturing cells ►limited work in process ►quality improvement ►production flexibility ►little inventory storage 2.1 small batch size JIT can produce the same amount of product in same time if setup . of lean manufacturing Key implications of lean manufacturing Lean manufacturing Lean manufacturing Traditional batch Traditional batch manufacturing manufacturing. What is lean manufacturing? What is lean manufacturing? Definitions : Definitions : ► ► LM is a set of tools and methodologies that aims for the conti