【正文】 entory Decisions in Strategy CR (2023) Prentice Hall, Inc. PLANNING ORGANIZING CONTROLLING Transport Strategy ? Transport fundamentals ? Transport decisions Customer service goals ? The product ? Logistics service ? Ord . proc. info. sys. Inventory Strategy ? Forecasting ? Inventory decisions ? Purchasing and supply scheduling decisions ? Storage fundamentals ? Storage decisions Location Strategy ? Location decisions ? The work planning process PLANNING ORGANIZING CONTROLLING 3 CR (2023) Prentice Hall, Inc. 什么是庫存 What are Inventories? ?庫存就是在企業(yè)生產(chǎn)和物流渠道中各點堆積的原材料、供給品、零部件、半成品和成品。 ——自下而上法 ? 另一種方法是管理一類產(chǎn)品而不是管理單獨一種產(chǎn)品 ——自上而下法 16 ? 供應(yīng)鏈管理鼓勵管理者將供應(yīng)渠道中更多的部分包括到計劃過程中來，供應(yīng)渠道中多個層級的庫存也成為核心問題。 庫存服務(wù)成本 庫存風險成本 23 CR (2023) Prentice Hall, Inc. Costs Relevant to Inventory Management ?庫存持有成本 Carrying costs Cost for holding the inventory over time The primary cost is the cost of money tied up in inventory, but also includes obsolescence（報廢） , insurance, personal property taxes, and storage costs Typically, costs range from the cost of short term capital to about 40%/year. The average is about 25%/year of the item value in inventory. 24 CR (2023) Prentice Hall, Inc. Relevant Costs (Cont’d) ?缺貨成本 Outofstock costs 銷售損失成本 Lost sales cost ?利潤損失 Profit immediately foregone ?商譽損失 Future profits foregone through loss of goodwill 缺貨成本 Backorder cost ?額外訂單處理費用 Costs of extra order handling ?額外的運輸和處理費用 Additional transportation and handling costs ?可能的安裝費用 Possibly additional setup costs 25 Inventory’s Conflicting Cost Patterns Cost 補給量 Replenishment quantity 缺貨成本 Stockout cost 采購成本Procurement cost 總成本 Total cost 最低訂貨成本 Minimum cost reorder quantity CR (2023) Prentice Hall, Inc. 916 26 術(shù)語匯編 Glossary of Terms sold being units of yprobabilit CP time lead of deviation standard and average , demand annual total of percent a as level service $ cost, relevant total units , or stock, safety on distributi demand pound on mean from deviations standard of number or deviate normal units level, inventory target days ., interval, order units quantity, point reorder quantity order system (P time cycle order plus time lead during or system) (Q time lead during stock in being of yprobabilit integral loss normal unit or nexpectatio partial on distributi demand pound of deviation standard price purchase unit per $ cost, stock of out units (d), demand of deviation standard unit per $ value, product year per % value, product of percent a as costs carrying $/order order, per cost tprocuremen units demand, period average units demand, annual average n ) ( 39。在有些制造和再供應(yīng)環(huán)節(jié)中，生產(chǎn)要持續(xù)一定時間，并且可能和需求同步進行。39。 ) 39。dks2D[SQ?=4 重復(fù) 2,3步直到 P和 Q不再變化 Repeat steps 2 and 3 until no further change 5 計算 ROP和其他所需的統(tǒng)計值 Compute ROP and other statistics 51 CR (2023) Prentice Hall, Inc. Reorder Point Control (Cont’d) Example Given: 每月需求預(yù)測 , d 11,107 units 預(yù)測標準差 , sd 3,099 units 補貨提前期 , LT months 產(chǎn)品價值 , C $處理訂單的成本 , S $10/order 庫存持有成本 , I 20%/year 缺貨成本 , k $Backordering is allowed 允許缺貨 Find optimal Q and P 52 CR (2023) Prentice Hall, Inc. Reorder Point Control (Cont’d) Example Given: Monthly demand forecast, d 11,107 units Std. error of forecast., sd 3,099 units Replenishment leadtime, LT months Item value, C $Cost for processing vendor order, S $10/order Carrying cost, I 20%/year Stockout cost, k $Backordering is allowed Find optimal Q and P 53 CR (2023) Prentice Hall, Inc. Reorder Point Control (Cont’d) Solution Estimate Q units 11,() 12)(10)2(11,107)( === IC2DSQEstimate P ()11,107(12) 0)()11,008( =?=?= DkQIC1PRevise Q Find App A, = and from App B, E()= For these data, s39。d。s60 CR (2023) Prentice Hall, Inc. Supply Chain Example (Cont’d) Average lead time days 7241 =??=??= oXiXpXLTNow days , 2239。因此可以通過設(shè)定 T*和 M*控制庫存。 x 1 4 1 2 . 7 2 20 L W h i t e R m S ea l A d v an t ag e B o n d F 1 4 5M* N o sto ck o r in su ffic ie n t sto ck to m e e t d e m a n d944 68 Pull Methods (Cont’d) 聯(lián)合訂貨 聯(lián)合訂貨的庫存管理包括確定聯(lián)合訂貨的所有產(chǎn)品的共同盤點時間，然后根據(jù)其成本和服務(wù)水平求出每種產(chǎn)品的最高庫存水平。 )2i i iiii i d i i d i iiiO S T I C DT C I C z s k s ETT+輊= + + + 臌邋邋70 CR (2023) Prentice Hall, Inc. Joint Ordering Example Item A B Average daily demand ( d ) 30 75 units Demand std. dev. ( s d ) 8 10 units Average lead time ( LT ) 14 14 days Annual carrying cost ( I ) 25 25 % Procurement cost ( S ) 30 20 $/order wit h mon cost ( O ) 80 $/order Instock probability ( P ) 80 92 % Product value ( C ) 170 200 $/unit Outofstock cost ( k ) 25 45 $/unit Selling days per year 365 365 days Given 71 CR (2023) Prentice Hall, Inc. Joint Ordering Example (Cont’d) Find mon review time days (75)][170(30)[] 20)](302[80 =???=*TFind target quantity (MAX) for item A units =?=?= A*d39。 =?=?= BdB LTTssBthen for z90%= units 1437)()(75 =??=BMAXwhich has an average inventory of units 223)()2/75( Avg. B =?=CR (2023) Prentice Hall, Inc. 73 CR (2023) Prentice Hall, Inc. Pull Methods (Cont’d) 最高庫存管理法 The MinMax variant 當庫存水平達到再訂貨點時，要訂購的貨物數(shù)量就是目標庫存量 M（最高點）與所持庫存量 q之差。按需存儲庫存控制法實際上是一種定期盤點的方法