chain(建构供应链模式)

1、PART II SolutionsModeling the Supply Chain1Modeling the Supply Chain(建構供應鏈模式)The examples in Chapter 4 show that even the simplest of systems can generatesurprisingly complex behavior. How, then, are managers to understand suchcomplex business systems as supply chains and manage them effectively? Th

2、eanswer, in a word, is modeling. The only way to understand complex systems isto construct simplified models of them, play with the models to see how theywork, and then apply what you learn to the real-world system. You may nothave thought about it this way, but you already do this with conceptual m

3、odelsall the time, even if the models are only in your mind. This chapter shows youhow to use these mental models more effectively, and it introduces two morepowerful kinds of modelsmathematical and simulation modelsthat you canuse as precision tools for prediction and control. You dont have to know

4、 howto build these more advanced models, but knowing what they are and when touse 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

5、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。2The Case for Models(模式之用處)Models are simplified representationsA model is nothing more than a simplified representat

6、ion of a real-world system. This representation can take a. wide variety offorms, 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 dang

7、erous 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,以及操作上更平安的方式呈現。3The Case for Models(模式之用處)Modeling aids the thre

8、e core processesModels 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 reass

9、emble 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

10、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。4The Case for Models(模式之用處)Modeling aids the three core pro

11、cessesModeling SupplyChains5The Case for Models(模式之用處)Models generate valuable predictionsOnce 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 reduc

12、e 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

13、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

14、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本钱與預期是否一樣？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？此類假设則問題(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。6The Case for Models(模式之用處)Good m

15、odels make for good decisionsTo 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 3.11reveal

16、ed 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

17、those operations, and their net effects on quality. In practice, a company wouldnt actually draw this tradeoff diagram once it had the model; it would simply use the model to find the lowest-cost solution. The only reason for drawing the diagram would be to help people understand why the new inspect

18、ion program is a win for both companies.良好模式產生良好決策要知道預測對供應鏈改善有多重要,回想一下第3章的例子,一個顧客與一個供應商想藉由減少總檢驗本钱來創造雙贏(shared win)。圖3.11互抵效應曲線顯示,最好的安排是供應商多花費1元的檢驗本钱,顧客則可少花費4元。此互抵線來自於何處？它只可能來自於一個模式的分析結果,該模式考慮到品質保證所需的作業、這些作業的本钱,以及它們在品質上的淨效果。實際上,一家企業不會真正畫出此互抵線圖,一旦他建構了模式；他只要使用此模式找出最低本钱解答即可。繪製此圖形的唯一理由乃在幫助大家瞭解,為何新的檢驗方案是個

19、雙贏的結果。7The Case for Models(模式之用處)Models are also used for controlModels are also used to control real-world systems, as shown on The right of Figure 5.1. This use of models is less obvious than the other two because the models used in control are usually implicitthat is, they are embedded in the des

20、ign of business systems, but are never communicated to the people who own and operate those systems. This problem is particularly acute in the case of software. All the various kinds of supply chain software described in the next chapter are based on very specific models about how production, distri

21、bution, replenishment, sales, and other business processes are carried out. Unfortunately, most of the companies that buy this software have no idea what those models are until after they install the system and discover that the embedded models dont support the way they do business. The impact of th

22、is mismatch can range from a minor nuisance to a complete failure of the system, which is certainly a devastating way to learn about the importance of business models.模式也使用於控制模式也使用於控制(control)真實世界系統,如圖5.1右邊所示。模式在控制上的使用比其他兩個功能較不明顯,那是因為使用於控制上的模式通常是內隱的(implicit)；亦即,它們被置入於商業系統的設計中,但是從來沒告知那些擁有與操作這些系統的人。這

23、個問題在軟體案例中特別地嚴重。在下一章介紹的各種不同類型供應鏈軟體均植基於非常特定的模式,有關於製造、配銷、補貨、銷售和其他商業程序如何被執行。不幸地,絕大局部企業在購買此軟體時,根本不知道有哪些模式,直到他們安裝系統後,才發現軟體所置入的模式無法支援他們的商業運作。這項不搭配的衝擊可能從小至一個芝麻蒜皮的問題,甚至大到系統的完全失敗都有可能,這當然是一種可怕的方式來瞭解商業模式的重要性。8The Case for Models(模式之用處)There are three basic types of ModelsBusiness models come in a wide variety o

24、f forms, but most of them fall into one of thethree broad categories shown in Figure 5.2. Conceptual models use diagrams anddescriptions to represent a business system. They can be created on white-boards,computer screens, or the backs of envelopes, and they provide simple, familiarstructures for re

25、asoning about the business. Mathematical models represent a business in terms of formulas and procedures, and they are solved by evaluating those formulas or procedures under a particular set of assumptions. Simulation models use software objects to represent the components of a business, and they a

26、re solved by running the model to see what happens when the objects interact with each other. Mathematical and simulation models are often referred to as formal models because they have strict forms and generate numerical predictions, in contrast to the informality of conceptual models.模式的三種根本類型商業模式

27、有多種形式,但大多數屬於圖5.2所示三種主要類型之二種。觀念模式(conceptual models)使用圖形與描述來表達一個商業系統。觀念模式可以在白板、電腦螢幕或是信封反面上創造,而且它們提供理解商業系統之簡單、熟悉的結構。數學模式(mathematical models)以公式(formulas)與運算程序(Procedures)代表一個商業系統,這些數學模式在一組特殊假設條件下,藉由估算公式與運算程序求得解答。模擬模式(simulation models)使用軟體物件(software objects)來表達一個企業的元件components),模擬模式藉由跑(running)模式來瞭

28、解不同物件互動後,所發生的情形來尋找解答。數學與模擬模式通常被稱為正規模式(formal models),因為它們有很嚴格的形式且會產生預測數值,與非正規化的觀念模式形成對比。9The Case for Models(模式之用處)Three kinds of Models10The Case for Models(模式之用處)Each type offers unique AdvantagesThe distinctions among these three kinds of models are not hard and fasthybrid forms are common. But t

29、he three types do represent three fundamentally different approaches to modeling, and each offers a unique set of capabilities and limitations. Because conceptual models are the easiest to build and understand, they are the best choice for achieving a shared understanding of the supply chain, partic

30、ularly when managers are involved in the modeling process. Mathematical models are the most powerful, and they are best used to predict and optimize the performance of the chain. Simulation models are the most flexible, and they should be used to study the behavior of a model under the most realisti

31、c business conditions.每種模式均有其獨特優勢這三種模式之區別並不困難而且非常快 混合型態(hybrid forms)很常見。不過這三種類型確實代表三種根本上不同的建模方法,而且每一類模式均有其獨特的能力與限制。因為觀念模式最容易建構與瞭解,對於達成供應鏈的共同性瞭解,特別是在經理人參與建模過程時,它們是最正确選擇。數學模式是最具能力的,它們使用在供應鏈績效的預測和最正确化上是最好的。模擬模式是最有彈性的,它們應該使用於瞭解在最真實企業環境下的商業模式行為。11The Case for Models(模式之用處)Choosing the type is a manageme

32、nt decisionAs a manager, you dont need to know how to use mathematical models and simulations; these formal models are usually implemented in software, and specialized skills are required to set them up and run them. But you do need to know how to use conceptual models because you are already applyi

33、ng them, whether well or badly, and you need to know what to expect of the other two types and when to trust their output. The next three sections provide a quick tour of the three kinds of models, and the final section offers some guidelines for using them to solve supply chain problems.選擇模式類型是個管理決

34、策作為一個經理人,你不需要知道如何使用數學模式與模擬模式；這些正規模式通常包含在軟體中,模式之設定與運用需要具備特殊技能。但你需要知道如何使用觀念模式,因為你已經在應用它們了,不管是好或壞；而且你需要知道對其他兩類模式應有的期待,以及何時去信任它們的產出。以下三節提供三種模式類型的快速導覽；最後一節則提供使用此三類模式解決供應鏈問題的一些指導方針。12Conceptual Models(觀念模式)Conceptual models are the simplestThe conceptual model is by far the simplest of the three types. Th

35、is sort of model is basically a description of a business system and is usually expressed as some combination of diagrams and explanations. To a large extent, the format depends on the experience of the modelersthose with the most training in modeling usually rely on detailed diagrams with formal no

36、tation to reduce ambiguity. By contrast, those with little or no training tend to express their models as verbal descriptions mixed with stories about how the business worksstories that can often be formalized as scenarios. Although generally less precise than diagrams, descriptions and scenarios of

37、ten capture the nature of the business in a way that formal diagrams cannot. The best conceptual models are usually a mix of diagrams, descriptions, and scenarios.觀念模式是最簡單的模式觀念模式是三種模式中最簡單的。這類模式根本上是對一個商業系統的描述,通常是以一些圖形與說明的組合性表達。一般來說,其形式取決於建模者的經驗具備嚴格訓練的建模者通常採用正式符號的詳細圖形,以減少模糊性。相較之下,較少或是沒有訓練的建模者則偏向於以口頭敘述

38、,摻雜一些關於商業運作的故事來表達他們的模式這些故事可以進一步轉變為一些情境(scenarios)。雖然通常比圖表不詳實,描述和情境時常以較簡易方式表達商業的本質,是正規模式所無法做到的。最好的觀念模式通常是圖形(diagrams)、敘述(descriptions)和情境(scenarios)三者的相結合。13Conceptual Models(觀念模式)The goal is o facilitate communicationRegardless of how you express a conceptual model, the key is to find the rightbalan

39、ce between precision and ease of communication. For systems analyststrained in the use of entity relationship (ER) diagramming, formal ER diagramsand detailed scenarios May be just the right tools. For managers who have never engaged in business modeling before, the right balance may be a combinatio

40、n of simple diagrams and informal explanations. But even with managers, some conventions are necessary to make the diagrams and explanations make sense. Otherwise the output of the process may contain more myth than model.觀念模式的目標是在促進溝通不管你如何表達一個觀念模式,關鍵在於找出介於精確和容易溝通之間的平衡點。對於受過實體關係繪圖方法(entity relations

41、hip (ER) diagramming)訓練的系統分析師而言,正式ER圖形以及詳細情境描述也許是正確的工具。對於不曾投入商業建模的經理人而言,好的平衡點也許是一種簡單圖形和非正式說明的組合。但即使是經理人,仍需遵循一些規範才能使圖形與說明讓人理解。否則,程序產出可能比模式本身更難讓人理解。14Conceptual Models(觀念模式)This book uses convergent engineeringThe diagrams in this book generally follow the conventions of convergent engineering,a model

42、ing technique I developed specifically to help managers formulate useful business models. In this approach, a business system consists of three basic kinds of objects: organizations, processes, and resources. As shown in Figure 5.3, each of these objects plays a different role in the model, and the

43、three relate to each other in ways that both constrain the model and make it more understandable at the businesslevel. Briefly put, organizations own resources and execute processes; processes consume one set of resources and generate another set; and resources are the source of all cost and value i

44、n the system. There is much more to the approach than this, of course (see my earlier book, Business Modeling with Object Technology), but this one-sentence summary illustrates what I view as an appropriate level of formalism for managers, and it should make the illustrations more meaningful to you

45、as well.本書採用收斂工程本書圖形主要採用收斂工程(convergent engineering)的慣例,乃筆者發展出的一種建模技術,特別有助於經理人建構有用的商業模式。在此方法中,一個商業系統是由三種根本物件(objects)所構成：組織(organizations)、程序(processes)和資源(resources)。如圖5.3所示,這些物件在此模式中個別扮演不一樣的角色,三者之相互關係在模式中彼此牽制,並讓此模式在商業水準上更加容易理解。簡單來說,組織擁有資源並且執行程序；程序消耗一組資源並產生另一組；而資源是所有本钱與價值在此系統中的來源。當然,收斂工程的內容遠較此G的介紹為

46、多(請參考筆者早期的著作：以物件技術進行商業建模(Business Modeling with Object Technology),但上述總結闡明筆者所認為經理人應具備的正規建模水準,並且這種建模方法的表達方式也應該會增加你對模式的理解程度。15Conceptual Models(觀念模式)This book uses convergent engineeringOrganizations,Processes, andResources16Conceptual Models(觀念模式)Group modeling is the most effectiveConceptual models

47、can be developed by individuals, but for systems that cross organizational boundaries, as supply chains inevitably do, the best approach is to assemble a team of representatives from all the groups involved and hammer out the model together. Many software tools have been designed to support this gro

48、up design process, but low-tech tools are often the most effective. Personally, Ive always gotten the best results from a combination of whiteboard diagrams and 5X7 index cards. Each card represents one of the organizations, processes, or resources required for the model, and participants take turns

49、 role-playing these objects as they interact in the operation of the business. The resulting process is highly engaging, often contentious, and alwayseducational as participants discover that each has a radically different understanding of how the business actually works. Once the group has assemble

50、d a consensus model out of its various conflicting perspectives, it has a solid foundation on which to build a better system.集體建模是最有效的觀念模式可以由個人來建構,但對於橫跨組織界線的系統來說,如供應鏈之例,最好的方法是從所有相關單位選出代表,組成一個工作團隊,一起完成模式之設計。許多軟體工具已經被設計用於支援此類集體設計(group design)程序,但低技術性工具(low-tech tools)經常是最有效的。就筆者而言,筆者總是從綜合使用白板繪圖與5X7索引

51、卡當中獲得最好的結果。每一張卡片代表模式中的一個組織、程序或資源,由參與者輪流扮演這些物件的角色,並進行相對應商業作業上的互動。最後產生的程序是人員高度投入且時常爭論不已所得,非常其有教育意義,因為參與者在過程中發現,每個人對企業實際運作方式上竟然有完全不同的理解。一旦這個團隊透過這樣的衝突過程完成具有共識的模式後,一個堅實的基礎即已建立,並可在此基礎上發展更好的系統。17Conceptual Models(觀念模式)Conceptual models are poor at predictionAlthough conceptual models form the basis for und

52、erstanding systems, they areof little value in prediction and control. It should be clear from the precedingchapter that even the simplest models can produce surprising interactions assoon as two or more components are hooked together, and our minds are simplynot equipped to extrapolate the effects

53、of these interactions. When we do try topuzzle out the behavior of a system, most of us tacitly assume that all therelations involved are linear. For reasons that psychologists are still teasing out,it is extremely difficult for us to extrapolate the behavior of nonlinearinteractions, so we naturall

54、y tend to work within our limitations and oversimplify real-world relationships. Going beyond these limitations requires us to turn to more powerful kinds of models.觀念模式的預測能力非常薄弱雖然觀念模式是瞭解系統的基礎,它們在預測與控制上的價值卻很小。從前一章中我們應該瞭解,即便是最簡單的模式,當兩個或兩個以上的模式元件要連結在一起時,都可能產生出令人驚訝的互動效果,而且我們的心智沒有足夠裝備去看出這些互動的效果。當我們試著去找出

55、一個系統的行為時,我們大多下意識地假定所有的關係都是線性的。基於一些心理學家仍舊會嘲笑(teasing out)的原因,人類在推斷非線性互動行為時存在非常高的困難度,因此,我們很自然地傾向於在這種限制條件下工作,並將真實世界的關係看得過於簡單。欲跳脫出這些限制條件,我們必須更改方向尋求更具效力的模式類型。 18Mathematical Models(數學模式)You already use mathematical modelsRemember those word problems you hated as a kid? They went something likethis: If a

56、boat moving upstream in a river flowing at 2 miles an hour takes 4hours to travel 3 miles, how many people were in the boat? These exerciseswere designed to teach you How to generate and apply mathematical models.And despite this early training, you do use mathematical models today. You just dont do

57、 it formally.你已經在使用數學模式了你還記得小時候你所討厭的代數問題嗎？例如,假设一條船每小時往上游移動2英哩,花了4小時旅行了3英哩,有多少人在這條船上？這些練習題是設計來教育你如何創造與應用數學模式。雖然這是學生時代的訓練,我們今日還是在使用數學模式,只是沒有很正式地應用它們而已。19Mathematical Models(數學模式)Production costing use a linear modelFor example, suppose your boss asks you how much it would cost to run batches of 1,000,

58、 2,000, or 3,000 audio CDs. You know that it costs $1,000 to set up the run and a dollar to make each CD once the run begins, so your total cost would be $ 1,000 plus $ 1 times the number of CDs, giving you $2,000, $3,000, and $4,000 for the three quantities. In working up those numbers, you used on

59、e of the most common mathematical models in all of businessa linear model. In effect, your model predicts a linear relation between cost and the number of CDs produced, as shown in Figure 5.4.生產本钱分析使用的是一個線性模式舉例來說,假设你的老闆問你分1,000、2,000、3,000幾個批量生產音樂光碟,各批量所需的生產本钱為何？你知道生產設置的固定本钱為1,000美元,並且每生產1片光碟要花費1美元,

60、所以你的總本钱將會是1,000美元加上1美元乘上光碟生產數量,得出三種批量的生產總本钱分別為2,000美元、3,000美元、4,000美元。在計算這些數值時,你已經在使用商業上最常應用的一種數學模式線性模式(linear model)。實際上,你的模式預測生產本钱和光碟產量為一種線性關係,如圖5.4所示。20Mathematical Models(數學模式)Production costing use a linear modelProduction costing by Volume21Mathematical Models(數學模式)Mathematical models are actu