PART II Solutions,Modeling the Supply Chain,Modeling the Supply Chain(建構供應鏈模式),The examples in Chapter 4 show that even the simplest of systems can generate surprisingly complex behavior. How, then, are managers to understand such complex business systems as supply chains and manage them effectively? The answer, in a word, is modeling. The only way to understand complex systems is to construct simplified models of them, play with the models to see how they work, and then apply what you learn to the real-world system. You may not have thought about it this way, but you already do this with conceptual models all the time, even if the models are only in your mind. This chapter shows you how to use these mental models more effectively, and it introduces two more powerful kinds of modelsmathematical and simulation modelsthat you can use as precision tools for prediction and control. You dont have to know how to build these more advanced models, but knowing what they are and when to use them is vital to managing a supply chain effectively. 第4章的例子顯示了部使最簡單的系統，也會產生令人意料不到的複雜行為。 那麼，經理人要如何瞭解供應鏈這麼複雜的商業系統，並且有效地管理它們 呢？簡言之，答案就是建模(modeling)。瞭解複雜系統的唯一方法是去建構它 們的簡單模式，操控這些模式看看它們運作的法則，然後將所學到的應用在 真實世界的系統。你或許從來沒有這麼想過，但事實上你卻一直在使用觀念 模式(conceptual models)思考真實世界的系統，即使這些模式只有在你的腦袋 裡。本章將教你如何更有效地使用這些心智模式(mental models)，並且介紹兩 種功能更強的模式數學模式與模擬模式，可作為預測與控制的精確工 具。你不一定需要知道如何建構這些進階的模式，但知道有這些進階模式存 在，以及何時使用它們，對於有效管理供應鏈是非常重要的。,The Case for Models(模式之用處),Models are simplified representations A model is nothing more than a simplified representation of a real- world system. This representation can take a. wide variety of forms, including verbal explanations, whiteboard diagrams, mathematical equations, physical structures, and computer programs. All these models serve a common purpose: They take a system that may be hard to understand or dangerous to manipulate, and they render it in a form that is easier to understand and safer to play with. 模式是簡化的表達方式 模式(model)不過是一個真實系統的簡化表達方式。模式的表 達有很多種方式，包含言語解釋、白板圖表、數學方程式、物理結 構以及電腦程式。所有類型的模式均具有一個共同目的：模式建構 會先選擇一個不易理解或其操作危險性的系統，再將這個系統以一 種更容易理解，以及操作上更安全的方式呈現。,The Case for Models(模式之用處),Modeling aids the three core processes Models help with all three of the key business processes described in Chapter 4: understanding, prediction, and control (Figure 5.1). Building a model of a system requires that you analyze the system to identify its key components, figure out how those components work, and then reassemble them in a way that replicates the essential behavior of the system. That basic sequence of analysis and synthesis is the surest way to understand complex systems. Its also the method underlying most scientific discoveries, engineering solutions, and business innovations. 建模協助三項核心程序 模式有助於第4章描述的三個關鍵商業程序(three of the key Business processes)：瞭解、預測及控制(見圖5.1)。建立一個系統的模式需要你 去分析此系統的關鍵元件，釐清這些元件如何運作，並用一些方法重組這 些元件，以複製此系統的必要行為(essential behavior)。分析與綜合的基 本順序(瞭解(understanding)、預測(prediction)及控制(control)，是瞭解 複雜系統的最好方法。此方法也是許多科學發現、工程解答，以及商業創 新當中所採用的方法。,The Case for Models(模式之用處),Modeling aids the three core processes Modeling Supply Chains,The Case for Models(模式之用處),Models generate valuable predictions Once you have assembled a model, you can use it as a test bed to generate predictions about how the system it represents would behave under a variety of conditions. Would building a new warehouse in Omaha reduce transportation costs as much as expected? Could the current supply chain support a 15% increase in demand? What would be the impact on cash flow of extending better credit terms to key customers? Its possible to answer what if“ questions such as these by changing the real-world system, but models provide answers faster, less expensively, and with a lot less risk to the company. Predictions generated by business models, in turn, increase your understanding of the real-world system, and you can use that increased understanding to further improve the quality of the model and its predictions. 模式可產生有價值的預測 一旦你組合出一個模式，你可以使用此模式作為一個測試工具，產生關於 模式所代表的系統在不同情況下的預測。在奧馬哈(Omaha)建立一個新倉 庫所減少的運輸成本與預期是否一樣？目前的供應鏈可以支持15的需求增 加量嗎？提供較好的信用條件給關鍵顧客，將對現金流量帶來什麼影響 呢？此類若則問題(what if guestjons)可透過改變真實世界系統來回 答，但是模式卻可更快速地提供答案、較不昂貴，且對公司而言風險較 小。由商業模式產生的預測將可增加我們對真實世界系統的瞭解，因而你 可以運用這些增加的瞭解來改善模式及其預測的品質。,The Case for Models(模式之用處),Good models make for good decisions To see how important predictions are to helping you improve your supply chain, think back to the example in Chapter 3, in which a customer and a supplier wanted to create a shared win by reducing their total inspection costs. The tradeoff curve shown in Figure 3.11revealed that the best arrangement was for the supplier to spend a dollar more on inspection, allowing the customer to spend four dollars less. Where did this tradeoff curve come from? It could only be the result of a model that took into account the operations required for quality assurance, the cost of those operations, and their net effects on quality. In practice, a company wouldnt actually draw this tradeoff diagram once it had