_12InventoryManagement(运营管理,英文版)

Click to edit Master title style,Click to edit Master text styles,Second level,Third level,Fourth level,Fifth level,Transparency Masters to accompany Operations Management, 5E (Heizer & Render),12-1,?,1998 by Prentice Hall, Inc.,A Simon & Schuster Company,Upper Saddle River, N.J. 07458,Operations Management,Inventory ManagementChapter 12,Transparency Masters to accompany Operations Management, 5E (Heizer & Render),12-2,?,1998 by Prentice Hall, Inc.,A Simon & Schuster Company,Upper Saddle River, N.J. 07458,Outline,Global Company Profile: Harley-Davidson,Functions of Inventory,Types of Inventory,Inventory Management,ABC Analysis,Record Accuracy,Cycle Counting,Control of Services Inventory,Transparency Masters to accompany Operations Management, 5E (Heizer & Render),12-3,?,1998 by Prentice Hall, Inc.,A Simon & Schuster Company,Upper Saddle River, N.J. 07458,Outline - continued,Inventory Models,Independent versus Dependent Demand,Holding, Ordering, and Setup Costs,Inventory Models for Independent Demand,Basic Economic Order Quantity (EOQ) Model,Minimizing Costs,Reorder Points Model,Production Order Quantity Model,Quantity Discount Models,Fixed-Period System,Transparency Masters to accompany Operations Management, 5E (Heizer & Render),12-4,?,1998 by Prentice Hall, Inc.,A Simon & Schuster Company,Upper Saddle River, N.J. 07458,Outline - continued,Probabilistic Models with Constant Lead Time,Fixed Period Systems,Transparency Masters to accompany Operations Management, 5E (Heizer & Render),12-5,?,1998 by Prentice Hall, Inc.,A Simon & Schuster Company,Upper Saddle River, N.J. 07458,Learning Objectives,Explain what inventory is,Explain how inventory is classified,Explain ABC Analysis and Cycle Counting,Compare inventory models,Use inventory models to find how much and when to order,Transparency Masters to accompany Operations Management, 5E (Heizer & Render),12-6,?,1998 by Prentice Hall, Inc.,A Simon & Schuster Company,Upper Saddle River, N.J. 07458,Harley-Davidson,1970s - intense competition from Honda and Yamaha,Emphasized quality improvement,Required:,tighter inventory control,JIT,product and process improvements,Primarily,total quality control program driven by inventory control policies,Transparency Masters to accompany Operations Management, 5E (Heizer & Render),12-7,?,1998 by Prentice Hall, Inc.,A Simon & Schuster Company,Upper Saddle River, N.J. 07458,Stock of materials,Stored capacity,Examples,?1995 Corel Corp.,?1984-1994 T/Maker Co.,?1984-1994 T/Maker Co.,?1995 Corel Corp.,What is Inventory?,Transparency Masters to accompany Operations Management, 5E (Heizer & Render),12-8,?,1998 by Prentice Hall, Inc.,A Simon & Schuster Company,Upper Saddle River, N.J. 07458,The Functions of Inventory,Provide a stock of goods to meet anticipated customer demand and provide a 搒election?of goods,Decouple suppliers from production and production from distribution,Allow one to take advantage of quantity discounts,To provide a hedge against inflation,To protect against shortages due to delivery variation,To permit operations to continue smoothly with the use of 搘ork-in-process,Transparency Masters to accompany Operations Management, 5E (Heizer & Render),12-9,?,1998 by Prentice Hall, Inc.,A Simon & Schuster Company,Upper Saddle River, N.J. 07458,Higher costs,Item cost (if purchased),Ordering (or setup) cost,Costs of forms, clerks?wages etc.,Holding (or carrying) cost,Building lease, insurance, taxes etc.,Difficult to control,Hides production problems,Disadvantages of Inventory,Transparency Masters to accompany Operations Management, 5E (Heizer & Render),12-10,?,1998 by Prentice Hall, Inc.,A Simon & Schuster Company,Upper Saddle River, N.J. 07458,Types of Inventory,Raw material,Work-in-process,Maintenance/repair/operating supplies,Finished goods,Transparency Masters to accompany Operations Management, 5E (Heizer & Render),12-11,?,1998 by Prentice Hall, Inc.,A Simon & Schuster Company,Upper Saddle River, N.J. 07458,Inventory,Process stage,Demand Type,Number & Value,Other,Raw Material WIP Finished Goods,Independent Dependent,A Items B Items C Items,Maintenance Dependent Operating,?1984-1994 T/Maker Co.,Inventory Classifications,Transparency Masters to accompany Operations Management, 5E (Heizer & Render),12-12,?,1998 by Prentice Hall, Inc.,A Simon & Schuster Company,Upper Saddle River, N.J. 07458,Run time,:,Job is at machine and being worked on,Setup time,:,Job is at the work station, and the work station is being setup.,Queue time,:,Job is where it should be, but is not being processed because other work precedes it.,Move time,:,The time a job spends in transit,Wait time,:,When one process is finished, but the job is waiting to be moved to the next work area.,Other,:,Just-in-case inventory.,The Material Flow Cycle,Other,Wait,Time,Move,Time,Queue,Time,Setup,Time,Run,Time,Input,Cycle Time,Output,Transparency Masters to accompany Operations Management, 5E (Heizer & Render),12-13,?,1998 by Prentice Hall, Inc.,A Simon & Schuster Company,Upper Saddle River, N.J. 07458,Divides on-hand inventory into 3 classes,A class, B class, C class,Basis is usually annual $ volume,$ volume = Annual demand x Unit cost,Policies based on ABC analysis,Develop class A suppliers more,Give tighter physical control of A items,Forecast A items more carefully,ABC Analysis,Transparency Masters to accompany Operations Management, 5E (Heizer & Render),12-14,?,1998 by Prentice Hall, Inc.,A Simon & Schuster Company,Upper Saddle River, N.J. 07458,0,20,40,60,80,100,0,50,100,150,% of Inventory Items,% Annual $ Usage,A,B,C,Class,% $ Vol,% Items,A,80,15,B,15,30,C,5,55,Classifying Items as ABC,Transparency Masters to accompany Operations Management, 5E (Heizer & Render),12-15,?,1998 by Prentice Hall, Inc.,A Simon & Schuster Company,Upper Saddle River, N.J. 07458,Physically counting a sample of total inventory on a regular basis,Used often with ABC classification,A items counted most often (e.g., daily),Cycle Counting,Transparency Masters to accompany Operations Management, 5E (Heizer & Render),12-16,?,1998 by Prentice Hall, Inc.,A Simon & Schuster Company,Upper Saddle River, N.J. 07458,Advantages of Cycle Counting,Eliminates shutdown and interruption of production necessary for annual physical inventories,Eliminates annual inventory adjustments,Provides trained personnel to audit the accuracy of inventory,Allows the cause of errors to be identified and remedial action to be taken,Maintains accurate inventory records,Transparency Masters to accompany Operations Management, 5E (Heizer & Render),12-17,?,1998 by Prentice Hall, Inc.,A Simon & Schuster Company,Upper Saddle River, N.J. 07458,Techniques for Controlling Service Inventory Include:,Good personnel selection, training, and discipline,Tight control of incoming shipments,Effective control of all goods leaving the facility,Transparency Masters to accompany Operations Management, 5E (Heizer & Render),12-18,?,1998 by Prentice Hall, Inc.,A Simon & Schuster Company,Upper Saddle River, N.J. 07458,Independent versus Dependent Demand,Independent demand - demand for item is independent of demand for any other item,Dependent demand - demand for item is dependent upon the demand for some other item,Transparency Masters to accompany Operations Management, 5E (Heizer & Render),12-19,?,1998 by Prentice Hall, Inc.,A Simon & Schuster Company,Upper Saddle River, N.J. 07458,Holding, Ordering, and Setup Costs,Holding costs - associated with holding or 揷arrying?inventory over time,Ordering costs - associated with costs of placing order and receiving goods,Setup costs - cost to prepare a machine or process for manufacturing an order,Transparency Masters to accompany Operations Management, 5E (Heizer & Render),12-20,?,1998 by Prentice Hall, Inc.,A Simon & Schuster Company,Upper Saddle River, N.J. 07458,Holding Costs,Obsolescence,Insurance,Extra staffing,Interest,Pilferage,Damage,Warehousing,Etc.,Transparency Masters to accompany Operations Management, 5E (Heizer & Render),12-21,?,1998 by Prentice Hall, Inc.,A Simon & Schuster Company,Upper Saddle River, N.J. 07458,Determining Inventory Holding Costs,Category,Housing costs,Material handling costs,Labor cost from extra handling,Investment costs,Pilferage, scrap, and obsolescence,Cost as a,% of Inventory Value,6%,(3 - 10%,3%,(1 - 3.5%0,3%,(3 -,5%),11%,(6 - 24%),3%,(2 - 5%),Transparency Masters to accompany Operations Management, 5E (Heizer & Render),12-22,?,1998 by Prentice Hall, Inc.,A Simon & Schuster Company,Upper Saddle River, N.J. 07458,Ordering Costs,Supplies,Forms,Order processing,Clerical support,Etc.,Transparency Masters to accompany Operations Management, 5E (Heizer & Render),12-23,?,1998 by Prentice Hall, Inc.,A Simon & Schuster Company,Upper Saddle River, N.J. 07458,Setup Costs,Clean-up costs,Re-tooling costs,Adjustment costs,Etc.,Transparency Masters to accompany Operations Management, 5E (Heizer & Render),12-24,?,1998 by Prentice Hall, Inc.,A Simon & Schuster Company,Upper Saddle River, N.J. 07458,Fixed order quantity models,Economic order quantity,Production order quantity,Quantity discount,Probabilistic models,Fixed order period models,Help answer the inventory planning questions!,?1984-1994 T/Maker Co.,Inventory Models,Transparency Masters to accompany Operations Management, 5E (Heizer & Render),12-25,?,1998 by Prentice Hall, Inc.,A Simon & Schuster Company,Upper Saddle River, N.J. 07458,Known and constant demand,Known and constant lead time,Instantaneous receipt of material,No quantity discounts,Only order (setup) cost and holding cost,No stockouts,EOQ Assumptions,Transparency Masters to accompany Operations Management, 5E (Heizer & Render),12-26,?,1998 by Prentice Hall, Inc.,A Simon & Schuster Company,Upper Saddle River, N.J. 07458,Order Quantity,Annual Cost,Holding Cost Curve,Total Cost Curve,Order (Setup) Cost Curve,Optimal Order Quantity (Q*),EOQ ModelHow Much to Order?,Transparency Masters to accompany Operations Management, 5E (Heizer & Render),12-27,?,1998 by Prentice Hall, Inc.,A Simon & Schuster Company,Upper Saddle River, N.J. 07458,More units must be stored if more ordered,Purchase Order,Description,Qty.,Microwave,1,Order quantity,Purchase Order,Description,Qty.,Microwave,1000,Order quantity,Why Holding Costs Increase,Transparency Masters to accompany Operations Management, 5E (Heizer & Render),12-28,?,1998 by Prentice Hall, Inc.,A Simon & Schuster Company,Upper Saddle River, N.J. 07458,Cost is spread over more units,Example: You need 1000 microwave ovens,Purchase Order,Description,Qty.,Microwave,1,Purchase Order,Description,Qty.,Microwave,1,Purchase Order,Description,Qty.,Microwave,1,Purchase Order,Description,Qty.,Microwave,1,1 Order (Postage $ 0.32),1000 Orders (Postage $320),Order quantity,Purchase,Order,Description,Qty,.,Microwave,1000,Why Order Costs Decrease,Transparency Masters to accompany Operations Management, 5E (Heizer & Render),12-29,?,1998 by Prentice Hall, Inc.,A Simon & Schuster Company,Upper Saddle River, N.J. 07458,EOQ ModelWhen To Order,Reorder Point (ROP),Time,Inventory Level,AverageInventory (Q*/2),Lead Time,Optimal Order Quantity(Q*),Transparency Masters to accompany Operations Management, 5E (Heizer & Render),12-30,?,1998 by Prentice Hall, Inc.,A Simon & Schuster Company,Upper Saddle River, N.J. 07458,Deriving an EOQ,Develop an expression for setup or ordering costs,Develop an expression for holding cost,Set setup cost equal to holding cost,Solve the resulting equation for the best order quantity,Transparency Masters to accompany Operations Management, 5E (Heizer & Render),12-31,?,1998 by Prentice Hall, Inc.,A Simon & Schuster Company,Upper Saddle River, N.J. 07458,Optimal Order Quantity,Expected Number of Orders,Expected Time Between Orders,Working Days,/,Year,Working Days,/,Year,=,=,=,=,=,=,=,=,Q*,D,S,H,N,D,Q,*,T,N,d,D,ROP,d,L,2,D,= Demand per year,S,= Setup (order) cost per order,H,= Holding (carrying) cost,d,= Demand per day,L,= Lead time in days,EOQ Model Equations,Transparency Masters to accompany Operations Management, 5E (Heizer & Render),12-32,?,1998 by Prentice Hall, Inc.,A Simon & Schuster Company,Upper Saddle River, N.J. 07458,Answers how much to order and when to order,Allows partial receipt of material,Other EOQ assumptions apply,Suited for production environment,Material produced, used immediately,Provides production lot size,Lower holding cost than EOQ model,Production Order Quantity Model,Transparency Masters to accompany Operations Management, 5E (Heizer & Render),12-33,?,1998 by Prentice Hall, Inc.,A Simon & Schuster Company,Upper Saddle River, N.J. 07458,Reasons for Variability in Production,Most variability is caused by tolerating waste or by poor management. Specific causes include:,employees, machines, and suppliers produce units that do not conform to standards, are late or are not the proper quantity,engineering drawings or specifications are inaccurate,production personnel try to produce beforedrawings or specifications are complete,customer demands are unknown,Transparency Masters to accompany Operations Management, 5E (Heizer & Render),12-34,?,1998 by Prentice Hall, Inc.,A Simon & Schuster Company,Upper Saddle River, N.J. 07458,POQ Model Inventory Levels,Inventory Level,Time,Supply Begins,Supply Ends,Production portion of cycle,Demand portion of cycle with no supply,Transparency Masters to accompany Operations Management, 5E (Heizer & Render),12-35,?,1998 by Prentice Hall, Inc.,A Simon & Schuster Company,Upper Saddle River, N.J. 07458,Time,Inventory Level,Production Portion of Cycle,Max. Inventory Q?1- d/p),Q*,Supply Begins,Supply Ends,Inventory level with no demand,Demand portion of cycle with no supply,POQ Model Inventory Levels,Transparency Masters to accompany Operations Management, 5E (Heizer & Render),12-36,?,1998 by Prentice Hall, Inc.,A Simon & Schuster Company,Upper Saddle River, N.J. 07458,D,= Demand per year,S,= Setup cost,H,= Holding cost,d,= Demand per day,p,= Production per day,POQ Model Equations,Optimal Order Quantity,Max.,Inventory,Level,Setup Cost,Holding Cost,=,=,-,=,*,=,*,=,Q,H*,d,p,Q,D,Q,S,p,*,1,(,0.5 * H * Q,-,d,p,1,),-,d,p,1,(,),2*D*S,(,),Transparency Masters to accompany Operations Management, 5E (Heizer & Render),12-37,?,1998 by Prentice Hall, Inc.,A Simon & Schuster Company,Upper Saddle River, N.J. 07458,Answers how much to order & when to order,Allows quantity discounts,Reduced price when item is purchased in larger quantities,Other EOQ assumptions apply,Trade-off is between lower price & increased holding cost,Quantity Discount Model,Transparency Masters to accompany Operations Management, 5E (Heizer & Render),12-38,?,1998 by Prentice Hall, Inc.,A Simon & Schuster Company,Upper Saddle River, N.J. 07458,Lowest cost not in discount range,Quantity Discount ModelHow Much to Order?,Order Quantity,Total Cost,TC for Discount 1,Discount Quantity 1,TC for Discount 2,TC for Discount 3,Discount,Quantity 2,Quantity Ordered,Price 1,Price 2,Price,3,Transparency Masters to accompany Operations Management, 5E (Heizer & Render),12-39,?,1998 by Prentice Hall, Inc.,A Simon & Schuster Company,Upper Saddle River, N.J. 07458,Answer how much & when to order,Allow demand to vary,Follows normal distribution,Other EOQ assumptions apply,Consider service level & safety stock,Service level =,1 - Probability of stockout,Higher service level means more safety stock,More safety stock means higher ROP,Probabilistic Models,Transparency Masters to accompany Operations Management, 5E (Heizer & Render),12-40,?,1998 by Prentice Hall, Inc.,A Simon & Schuster Company,Upper Saddle River, N.J. 07458,Probabilistic ModelsWhen to Order?,Reorder Point (ROP),X,Safety Stock (SS),Time,Inventory Level,Optimal,Order Quantity,Lead Time,SS,ROP,Service Level,P(Stockout),Place order,Receive order,Freq,Transparency Masters to accompany Operations Management, 5E (Heizer & Render),12-41,?,1998 by Prentice Hall, Inc.,A Simon & Schuster Company,Upper Saddle River, N.J. 07458,Reorder Point (ROP),Safety Stock (SS),Time,Inventory Level,Optimal,Order,Quantity,SS,ROP,Service Level,P(Stockout),Freq,Lead Time,Place order,Receive order,Probabilistic ModelsWhen to Order,Transparency Masters to accompany Operations Management, 5E (Heizer & Render),12-42,?,1998 by Prentice Hall, Inc.,A Simon & Schuster Company,Upper Saddle River, N.J. 07458,Answers how much to order,Orders placed at fixed intervals,Inventory brought up to target amount,Amount ordered varies,No continuous inventory count,Possibility of stockout between intervals,Useful when vendors visit routinely,Example: P&G representative calls every 2 weeks,Fixed Period Model,Transparency Masters to accompany Operations Management, 5E (Heizer & Render),12-43,?,1998 by Prentice Hall, Inc.,A Simon & Schuster Company,Upper Saddle River, N.J. 07458,Time,Inventory Level,Target maximum,Period,Period,Period,Fixed Period ModelWhen to Order?,