【正文】 urement costs Cost of preparing the order Cost of order transmission Cost of production setup if appropriate Cost of materials handling or processing at the receiving dock Price of the goods 22 CR (2023) Prentice Hall, Inc. ?庫(kù)存持有成本 Carrying costs 空間成本。 庫(kù)存服務(wù)成本 庫(kù)存風(fēng)險(xiǎn)成本 23 CR (2023) Prentice Hall, Inc. Costs Relevant to Inventory Management ?庫(kù)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(bào)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(rùn)損失 Profit immediately foregone ?商譽(yù)損失 Future profits foregone through loss of goodwill 缺貨成本 Backorder cost ?額外訂單處理費(fèi)用 Costs of extra order handling ?額外的運(yùn)輸和處理費(fèi)用 Additional transportation and handling costs ?可能的安裝費(fèi)用 Possibly additional setup costs 25 Inventory’s Conflicting Cost Patterns Cost 補(bǔ)給量 Replenishment quantity 缺貨成本 Stockout cost 采購(gòu)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(yǔ)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。 z d = = = = = = = = = = = = = = = = = = = = = 27 ? 產(chǎn)或采購(gòu)期間的需求量 ? ? ? ? ? ，將超過(guò)總凈需求的部分分配到各存儲(chǔ)點(diǎn) ? 每個(gè)存儲(chǔ)點(diǎn)的貨物總量 28 ? （ 1）需求是一次性的、高季度性的或持續(xù)性的情況 ? （ 2）訂貨程序在某一庫(kù)存水平上啟動(dòng)或由庫(kù)存盤點(diǎn)程序啟動(dòng) ? （ 3）需求和補(bǔ)貨提前期存在不同程度不確定性的情況 29 CR (2023) Prentice Hall, Inc. Single Order Purchasing Make a onetime purchase of an item. How much to order? Procedure: 平衡利潤(rùn)增加額與損失增加額 利潤(rùn) =單位價(jià)格 單位成本 損失 = 單位成本 單位殘值 如果考慮一定量產(chǎn)品被售出的概率 CPn，預(yù)期收益和預(yù)期損失在以下點(diǎn)得到平衡 CPn x 損失 = (1 CPn) x 利潤(rùn) or CPn = 利潤(rùn) /(利潤(rùn) + 損失 ) CPn代表至多售出 n個(gè)單位產(chǎn)品的累積概率 Daily stocking of newspapers in vending machines is a good example 918 30 CR (2023) Prentice Hall, Inc. Single Order Purchasing Make a onetime purchase of an item. How much to order? Procedure: Balance incremental profit against incremental loss. Profit = Price per unit ? Cost per unit Loss = Cost per unit ? Salvage value per unit If CPn is probability of n units being sold, then CPn x Loss = (1 ? CPn) x Profit or CPn = Profit/(Profit + Loss) Now, increase order quantity until CPn just matches cumulative probability of selling additional units. Daily stocking of newspapers in vending machines is a good example 918 31 CR (2023) Prentice Hall, Inc. Single Order Purchasing (Cont’d) Example A clothing item is purchased for a seasonal sale. It costs $35, but it has a sale price of $50. After the season is over, it is marked down by 50% to clear the merchandise. The estimated quantities to be sold are: Number of items, n Probability of selling exactly n items Cumulative probability 10 15 20 25 30 35 919 32 CR (2023) Prentice Hall, Inc. Single Order Purchasing (Cont’d) Solution Profit = $5035 = $15 Loss = $35 ()(50) = $10 CPn = 15/(15 + 10) = CPn is between 15 and 20 items, round up and order 20 items. 33 2ICDS TC?=?= 庫(kù)存持有成本采購(gòu)成本 TC—每年總的相關(guān)成本（美元） Q—補(bǔ)充存貨的訂單批量（件） D—對(duì)庫(kù)存產(chǎn)品的年需求量（件） S—采購(gòu)成本（美元 /訂單） C—庫(kù)存產(chǎn)品的價(jià)值（美元 /件） I—庫(kù)存持有成本占產(chǎn)品價(jià)值的比例（ %/年） Develop a simple control system by finding the replenishment quantity (Q) and the reorder point (ROP). The relevant total cost is:總成本 =采購(gòu)成本和庫(kù)存成本 注 :需求和提前期確定—周期性的庫(kù)存管理 921 34 2ICDS TC?=?= 庫(kù)存持有成本采購(gòu)成本 TC—每年總的相關(guān)成本（美元） Q—補(bǔ)充存貨的訂單批量（件） D—對(duì)庫(kù)存產(chǎn)品的年需求量（件） S—采購(gòu)成本（美元 /訂單） C—庫(kù)存產(chǎn)品的價(jià)值（美元 /件） I—庫(kù)存持有成本占產(chǎn)品價(jià)值的比例（ %/年） Develop a simple control system by finding the replenishment quantity (Q) and the reorder point (ROP). The relevant total cost is:總成本 =采購(gòu)成本和庫(kù)存成本 Note: No uncertainty in demand or lead time—manage regular (cycle) stock only 921 35 CR (2023) Prentice Hall, Inc. 0 Time Lead time Lead time Order Placed Order Placed Order Received Order Received Inventory Level Reorder point, R Q Reorder Point Method Under Certainty for a Single Item Quantity onhand plus onorder 922 36 Given: d = 50 units/week I = 10%/year S = $10/order C = $5/unit LT = 3 weeks Note: No uncertainty in demand or lead time—manage regular (cycle) stock only 921 37 CR (2023) Prentice Hall, Inc. Using differential calculus, the optimal value for Q will be: units 322)0)/((50x52)(1 === 2DS/IC*The reorder point is: ROP = d(LT) = 3(50) = 150 units Famous EOQ formula