Presentation on theme: "International Operations Management"— Presentation transcript:
1International Operations Management MGMT 6367Lecture 03Instructor: Yan QinFall 2013
2Outline Introduction to Supply Chain Management Definition of Supply Chain ManagementBullwhip effectCauses and Mitigating strategiesAchieving coordination in practiceSupply chain performance measuresSupplement: Common demand forecasting methods
3A Supply ChainThis supply chain includes all the interactions among suppliers, manufacturers, distributors, and customers. Each manufacturer can have different tiers of suppliers.S3S2Distributor(s)S1ManufacturerS2Retailer(s)Tier 3SuppliersTier 2SuppliersTier 1SuppliersCustomers
4Example: Supply Chain of Bottled Water YouTube Video:This video “describes the complex supply chain of a simple product, a bottle of water. The video also illustrates the importance of supply chain managers and their skill sets in our modern global economy for both manufacturing and service industries.”
5Supply Chain Management Definitions of Supply Chain ManagementSupply Chain Management is the integration of the activities that procure materials and services, transform them into intermediate good and final products, and deliver them to customers.Supply Chain Management deals with the management of materials, information, and financial flows in a network consisting of suppliers, manufacturers, distributors, and customers. -- Prof. Hau Lee, Stanford Supply Chain Forum
6Typical Questions to ask Examples of questions to be answered in a Supply Chain:It is less costly to transport product by boat or truck, but air freight sometimes can save you a lot of time. So which one to pick?Number, size, and location of warehouses, plants, and terminalsHow much inventory to stock and what control policies to use?Make or Buy? That is, shall we produce a component or service in- house or purchase it from an outside source?What type of relationship should be established among members in the same supply chain?…
7Bullwhip Effect Local Optimization Members of the chain are inclined to focus on maximizing local profit or minimizing immediate cost based on their limited knowledge.Prisoner’s dilemma can be a good example of the sub-optimal result of local optimization.The result is that the fluctuation in orders increases as orders move through the supply chain, which is called Bullwhip effect.
8Bullwhip Effect (Cont.) Why called Bullwhip effect?Suppliers(Upstream)End Customer(Downstream)
9Behavioral causes of Bull-whip effect Failure to understand the impact of individual decisions on the supply chain as a whole is one cause of the bullwhip effect.Risk-averse attitudes of decision makers
10Major Non-behavioral Causes Demand Forecast updateExplanation:When a downstream player places an order, the upstream manager take it as a signal about future demand.Many of the forecasting methods place substantial weight on recently observed demand, leading to distortion when there is a sudden peak or drop in orders.Remedies:In-time demand sharing among members.Some companies convinced their suppliers to locate their production faculties nearby.POS, EDI, or Vendor Managed Inventory (VMI)
11Examples of Remedies - Demand Forecast JC Penny and Levi Strauss are linked with an EDI that allows Levi Strauss to obtain sales data. These data allow Levi Strauss to better plan the production process as well as better control inventory and delivery. The savings leads to a reduction in costs and prices, benefitting both JC Penny and Levi Strauss.McKesson developed a close relationship with Johnson & Johnson, one of its major suppliers. Both firms receive data on inventory, POS, and customer information through a joint information system. This enables Johnson & Johnson to provide better services to McKesson, which in turn improves the level of service that McKesson is able to provide to its customers.
12Major Causes of Bullwhip Effect Order BatchingExplanation: Companies may want to accumulate demand before issuing an order to take advantage of the economies of scale in order placing or transportation.Remedies:Use Electronic purchasing to reduce ordering costsOne solution to discourage shipment consolidation can be to outsource the transportation activities.
13Major Causes of Bullwhip Effect Price FluctuationExplanation: Companies may buy supplies well in advance of demand as a result of special trade deals and consumer promotions, such as discounts and rebates.Remedies:Every-Day-Low-Price can be one solution;Adopt Continuous Replenishment Program (CRP), that is, products are replenished only for the sold amount.
14Major Causes of Bullwhip Effect Rationing and Shortage GamingExplanation:When product demand exceeds product supply, manufacturers tend to ration their products to customers by allocating in proportion to the amount ordered.Remedies:One possible way is to allocate products in proportion to past sales.Impose high order cancellation fee.
15Achieving SC Coordination in Practice Steps to follow:Quantify the bullwhip effectGet top management commitment for coordinationDevote resources to coordinationFocus on communication with other stagesTry to achieve coordination in the entire supply chain networkUse technology to improve connectivity in the supply chainShare the benefits of coordination equitablyThe slides on “Achieving SC Coordination” are written based on the relevant chapter from “Supply Chain Management” by Chopra and Meindl.
16How to evaluate Supply Chain performance The evaluation of Supply Chain with focuses on procurement and inventory tends to answer two questions:How well the supply chain is performing; andHow well assets are utilized.Benchmarking is used to answer the 1st question.To answer the 2nd question, three measures can be of help.Percent of assets invested in inventoryInventory TurnoverWeeks-of-Supply
17BenchmarkingBenchmarking is the process of comparing one’s own business processes to the industry bests or the best practices in other industries.Typical FirmsBenchmark FirmsLead time (in weeks)158Time spent placing and order42 mins15 minsPercent of late delivery33%2%Percent of rejected material1.5%0.0001%Number of shortages per year4004To start the process, a firm must decide on the process it wishes to evaluate and select the benchmark firms. Relevant data need to be collected to conduct the comparison. The result is usually improved process performance by achieving the targets set during the process.
18How well assets are utilized Percent of assets invested in inventoryExample: Home Depot had $11.4 billion invested in inventory and total assets of $44.4 billion in 2006.Then, its Percent of assets invested in inventory = (11.4/44.4)* 100% = 25.7%
19Inventory Turnover Inventory turnover (computed on an annual basis) Inventory turnover = Cost of goods sold / Inventory InvestmentCost of goods sold is the cost to produce the goods or services sold for a given period.The inventory investment can be:The sum of the beginning and the ending inventory values divided by 2; ORThe sum of the values of different types of inventories being held in the system.
20Example: Inventory Turnover PepsiCo. Inc provides the following in its 2005 annual report (in $ billion). Determine its inventory turnover.Net Revenue$32.5Cost of goods sold$14.2Inventory:Raw Material inventory$.74WIP inventory$.11Finished good inventory$.84
21Weeks-of-SupplyWeeks-of-supply indicates for how long the average amount of on-hand inventory may last based on the current demand.Weeks-of-supply = Inventory Investment / (cost of goods sold / 52 weeks)For weeks-of-supply, it is usually the lower the better.It tells the inventory manager how long the current on hand inventory will last based on current demand.
22Supplement: Demand Forecasting Methods There are two general approaches to forecasting:Qualitative, which incorporate factors such as decision maker’s intuition, emotions, personal experience, and so on.Quantitative, which uses a variety of models that rely on historical data to forecast demand.
23Common types of Qualitative Methods Jury of execution opinion: The opinions of a group of high-level experts or mangers are pooled together to arrive at a group estimate of demand.Delphi method: Surveys and questionnaires are distributed to a group of selected respondents. Then a group of 5-10 experts make the decision based on the responses.The state of Alaska used Delphi method to develop its long- range economic forecast.
24Common types of Qualitative Methods Sales force composite: Combine each sales person’s estimate of future demand.Lexus dealers meet every quarter to talk about the sales, such as what is selling, in what colors, so the manufacturer has an idea what to build.Consumer market survey: Collect information from current or potential customers about future purchasing plan.
25Common Quantitative Methods Time series models predict on the assumption that the future is a function of the past.Naïve approachMoving averagesExponential smoothingAssociative Models incorporate variables that might influence the quantity being forecast.For example, an associative model for lawn mowers sales might use factors such as new housing starts, advertising budget and so on.
26Naïve ApproachAssume that demand in the next period will be equal to the most recent period.Bull-whip effect will be maximized under this forecasting method.
27Moving averagesA moving-average forecast uses a number of historical actual data values to generate a forecast.It is useful if we can assume that market demands will stay fairly steady over time.An n-period moving-average model:Moving average forecast for demand in period (n+1)= 𝑆𝑢𝑚 𝑜𝑓 𝑡ℎ𝑒 𝑎𝑐𝑡𝑢𝑎𝑙 𝑑𝑒𝑚𝑎𝑛𝑑𝑠 𝑖𝑛 𝑡ℎ𝑒 𝑝𝑟𝑒𝑣𝑖𝑜𝑢𝑠 𝑛 𝑝𝑒𝑟𝑖𝑜𝑑𝑠 𝑛Usually the n is 3, 6, 9 months.
28Example: 3-/6-month moving average forecast Actual Sales3-Month forecast6-MonthForecastJan10NAFeb12March13April16( )/3May19( )/3June23July26( )/6Aug30
29Weighted moving averages Weights can be used to place more emphasis on recent values or older values.A weighted n-period moving average:Forecast for the demand in period (n+1)= 𝑖=1 𝑛 (𝑤 𝑖 × 𝐷 𝑖 ) 𝑖=1 𝑛 𝑤 𝑖𝑤 𝑖 is the weight attached to the actual demand in period i𝐷 𝑖 is the actual demand in period i
30Example: Weighted moving average The following table summarizes the actual demands for a product in the past 6 weeks.What is the forecast for Week 4 if the company wants to use the 3-period weighted moving average method with the weight of 0.6 for the most recent demand, 0.3 for the 2nd most recent demand, and 0.1 for the oldest actual demand.WeekActual Demand1252343604530638
31Limitations of moving averages Increasing the size of n makes the method less sensitive to real changes in the data;Moving averages cannot predict changes to either higher or lower levels in time. They lag the actual values.Moving averages require extensive records of past data.
32Exponential smoothing Exponential smoothing is a sophisticated weighted- moving-average method.Call 𝛼 a smoothing constant, valued between 0 an 1. Usually from 0.05 to 0.50 for business application.New forecast =𝐿𝑎𝑠𝑡 𝑝𝑒𝑟𝑖𝑜 𝑑 ′ 𝑠 𝑓𝑜𝑟𝑒𝑐𝑎𝑠𝑡+ 𝛼 ×(𝐿𝑎𝑠𝑡 𝑝𝑒𝑟𝑖𝑜 𝑑 ′ 𝑠 𝑎𝑐𝑡𝑢𝑎𝑙 𝑑𝑒𝑚𝑎𝑛𝑑 −𝐿𝑎𝑠𝑡 𝑝𝑒𝑟𝑖𝑜 𝑑 ′ 𝑠 𝑓𝑜𝑟𝑒𝑐𝑎𝑠𝑡)
33Example: Exponential smoothing Suppose the actual demand for year 2012 was 250 and the forecast for the demand was 230. Set the smoothing constant α = 0.1.What is the exponential smoothing forecast for year 2013?
34Next Week Design for Supply Chain efficiency Supply Chain Coordination Buy Back contractQuantity DiscountMore Supply Chain contractsCycle inventory