及時化(just in time，JIT)概述,提出者：豐田汽車副社長，大野耐一(Taiichi Ohno)。 意義 將需要的物品在必須的時間供應必須的品質與數量到需要的地點。 目的 消除混亂 使系統彈性化 降低籌置與前置時間 存量最小化 消除浪費,1,及時化生產系統,JIT目標和建築架構的歸納,產品設計,流程設計,人員因素,製造規劃,避免中斷,使系統有彈性,排除浪費,平衡 迅速的流程,最終目標,支援目標,建築架構,2,及時化生產系統,常見的資源浪費1,超額生產(overproduction) 等候時間(waiting time) 不必要的運送(unnecessary transporting) 存貨(inventory) 加工浪費(processing waste) 不必要的生產步驟 產出瑕疵品,3,及時化生產系統,常見的資源浪費2,無效的工作方法(inefficient work method) 不佳的佈置和物料搬運模式，增加在製品存貨 產品不良 再製成本 消費者不滿意造成銷售損失,4,及時化生產系統,Waste in Operations,5,及時化生產系統,Waste in Operations,6,及時化生產系統,Waste in Operations,7,及時化生產系統,The Principles of the TOYOTA Production System (TPS)1,All work must be completely specified as to content, sequence, timing, and outcome. Every customer-supplier connection must be direct, unambiguously specifying the people involved, the form and quantity of the services or goods to be provided, the way the requests are made by each customer, and the expected time in which the requests will be met.,8,及時化生產系統,The Principles of the TOYOTA Production System (TPS)2,The pathway for every service and product must be simple and direct. Any improvement to the system must be made in accordance with the scientific method, under the guidance of a teacher, at the lowest possible organizational level.,9,及時化生產系統,Basic Elements of JIT1,標準的零件(產品設計) 模組化設計(產品設計) 高產能的系統(產品設計) 可同時生產(產品設計),將員工視為資產(人員/組織的要素) 訓練員工，使其變成多能工(人員/組織的要素) 持續改善(人員/組織的要素) 成本會計(人員/組織的要素) 領導與專案管理(人員/組織的要素),10,及時化生產系統,Basic Elements of JIT2,Cellular layouts (製程設計 Pull production system(製造規劃與控制) Flexible resources (製程設計) Kanban production control(製造規劃與控制) Small-lot production(製程設計),Quick setups (製程設計) Uniform production levels (製造規劃與控制) Quality at the source(製程設計) Total productive maintenance (製造規劃與控制) Supplier networks(製造規劃與控制),11,及時化生產系統,Flexible Resources,Multifunctional workers (多能工) Perform more than one job General purpose machines (通用設備) Perform several basic functions Study operators 每一工作站從前一站拉拔所需產出。,16,及時化生產系統,Kanban Production Control System(看板生產管制系統),Kanban card indicates standard quantity of production Derived from two-bin inventory system(雙倉制) Kanban maintains discipline of pull production Production kanban(生產看板) authorizes production Withdrawal kanban(提領看板) authorizes movement of goods,17,及時化生產系統,A Sample Kanban,18,及時化生產系統,The Origin of Kanban,19,及時化生產系統,Types of Kanbans Dual kanbans,20,及時化生產系統,Single-Card Kanban System,21,及時化生產系統,Storage area,Empty containers,Full containers,Single-Card Kanban System,Receiving post,Kanban card for product 1,Kanban card for product 2,22,及時化生產系統,Storage area,Empty containers,Full containers,Single-Card Kanban System,Receiving post,Kanban card for product 1,Kanban card for product 2,23,及時化生產系統,Storage area,Empty containers,Full containers,Single-Card Kanban System,Receiving post,Kanban card for product 1,Kanban card for product 2,24,及時化生產系統,Storage area,Empty containers,Full containers,Single-Card Kanban System,Receiving post,Kanban card for product 1,Kanban card for product 2,25,及時化生產系統,Storage area,Empty containers,Full containers,Single-Card Kanban System,Receiving post,Kanban card for product 1,Kanban card for product 2,26,及時化生產系統,Storage area,Empty containers,Full containers,Single-Card Kanban System,Receiving post,Kanban card for product 1,Kanban card for product 2,Fabrication cell,O1,O2,O3,O2,27,及時化生產系統,看板系統 single kanban,28,及時化生產系統,Dual kanban vs. single kanban,Dual kanban Is used when material is not necessarily moving between two consecutive processes, or when there is more than one input to a process and the inputs are dispersed throughout the facility. Single kanban Is used when the processes are tightly linked.,29,及時化生產系統,Types of Kanbans,Kanban Square Marked area designed to hold items Signal Kanban Triangular kanban used to signal production at the previous workstation Material Kanban Used to order material in advance of a process Supplier Kanbans Rotate between the factory and suppliers,30,及時化生產系統,Types of Kanbans kanban square and kanban racks,31,及時化生產系統,Types of Kanbans signal kanbans,32,及時化生產系統,看板管理系統之規則,不要把不良品交給後製程。 由後製程到前製程來領取零件。 前製程僅生產將被後製程領用去的數量。 生產必須平衡。 看板只做為微調整的手段，其張數必須減到最少。 製程必須安定化、合理化。,33,及時化生產系統,Single-Card Kanban System,KANBAN,Part Number:1234567Z Location:Aisle 5 Bin 47 Lot Quantity:6 Supplier:WS 83 Customer:WS 116,Each container must have a card Assembly always withdraws from fabrication (pull system) Containers cannot be moved without a kanban Containers should contain the same number of parts Only good parts are passed along Production should not exceed authorization,34,及時化生產系統,看板(容器)數量之決定1,K=容器數量。 d=工作中心之計劃使用率(預期每日需求) 。 p=每箱容器零件之平均加工時間。 W=在生產過程中之平均等候時間，加上每箱物料的搬運時間。 C=標準容器之零件容量。 X=政策變數。反應生產系統的效率(10%以內),35,及時化生產系統,看板(容器)數量之決定2,36,及時化生產系統,看板(容器)數量之決定3,where N = number of kanbans or containers d = average demand over some time period L = lead time to replenish an order S = safety stock C = container size,37,及時化生產系統,容器數量決定範例,某汽車零件公司生產4輪傳動車的方向盤及暫停