外文翻譯模塊化設(shè)計：產(chǎn)品設(shè)計的分解與整合

1、吉林化工學(xué)院畢業(yè)設(shè)計外文翻譯英文原文:design for modularity: product design for decomposition and integrationabstractin the last few years, corporation has engaged in studies to improve their design processes, ranging from marketing to support. recent government, academic and industrial sector initiatives have sought

2、advance technologies for developing and managing product development environment. many companies have established a concurrent design process for their product development and have recognized a need for tools in evaluating the level of decomposition and integration, while analyzing the impact on the

3、 final design. this article will propose a three-phase methodology for design of products while considering modularity, assembly and manufacture. keywordsmodularity, group technology, optimization, decomposition, classification1. introductionmodular design is a design technique that can be used to d

4、evelop complex products using similar components . components used in a modular product must have features that enable them to be coupled together to form a complex product. modular design can be also viewed as the process of producing units that perform discrete functions, and then the units are co

5、nnected together to provide a variety of functions. modular design emphasizes the minimization of interactions between components, which will enable components to be designed and produced independently from each other. each component, designed for modularity, is supposed to support one or more funct

6、ion. when components are structured together, to form a product, they will support a larger or general function. this shows the importance of analyzing the product function and decomposing it into sub-functions that can be satisfied by different functional modules. modularity can be applied in the p

7、roduct design, design problems, production systems, or all three. it is preferable to use the modular design in all three types at the same time.modular products refer to products that fulfill various overall functions through the combination of distinct building blocks or modules. in the sense that

8、 the overall function, performed by the product, can be divided into sub functions that can be implemented by different modules or components. an important aspect of modular products is the creation of a basic core unit to which different elements (modules) can be fitted, thus enabling a variety of

9、versions of the same module to be produced. the core should have sufficient capacity to cope with all expected variations in performance and usage.most design problems can be broken down into a set of easy to manage simpler sub-problems. sometimes complex problems are reduced into easier sub-problem

10、s, where a small change in the solution of one sub-problem can lead to a change in other sub-problems solutions. this means that the decomposition has resulted in functionally dependent sub-problems. modularity focuses on decomposing the overall problem into functionally independent sub-problems, in

11、 which interaction or interdependence between sub-problems is minimized. thus, a change in the solution of one problem may lead to a minor modification in other problems, or it may have no effect on other sub-problems.modularity in production systems aims at building production systems from standard

12、ized modular machines. the fact that a wide diversity of production requirements exists has led to the introduction of a variety of production machinery, and a lack of agreement on what the building blocks should be. this means that there are no standards for modular machinery. in order to build a m

13、odular production system, production machinery must be classified into functional groups from which a selection of a modular production system can be made to respond to different production requirements. rogers classified production machinery into four basic groups of “primitive” production elements

14、. these are process machine primitives, motion units, modular fixtures, and configurable control units. it is argued that if a selection is made from these four categories, it will be possible to build a diverse range of efficient, automated and integrated production system.2overview of product deve

15、lopmentproduct development is a necessary and important part of the activities performed by a manufacturing firm. due to changes in manufacturing technology, consumer preferences, and government regulations (to name a few influences), existing products will become less profitable over time. the sale

16、s volume of a typical product starts slowly, accelerates, becomes flat, and then steadily declines. although there may be a few products that remain profitable for many years, firms continually develop new products that will generate more profits. product development determines what the firm will ma

17、nufacture and sell. that is, it attempts to design products that customers will buy and to design manufacturing processes that meet customer demand profitably. poor decisions during product development lead to products that no one wants to buy and products that are expensive to manufacture in suffic

18、ient quantity.a product development process is the set of activities needed to bring a new product to market. a product development organization includes the engineers, managers, and other personnel who make process and product engineering decisions and perform these activities. (note that, in this

19、paper, the term new product covers the redesign of an existing product as well.)because making good decisions requires expertise and an organization of people can be experts in only a few things, a manufacturing firm specializes in a certain class of products. it focuses its attention on the market

20、for that class of products, the technologies available to produce that class, and the regulations relevant to that class.like other parts of the business, a product development organization seeks to maximize the profit of the manufacturing firm subject to the relevant regulatory and ethical constrai

21、nts and other conditions that the firms owners impose based on their values. a product development organization does this by regularly introducing new products that the firm can manufacture, market, and sell. fundamentally, then, a product development organization transforms information about the wo

22、rld (e.g., technology, preferences, and regulations) into information about products and processes that will generate profits for the firm. it performs this transformation through decision-making (herrmann and schmidt, 2002). because the design problem is highly complex, product development teams de

23、compose the problem into a product development process, which provides the mechanisms for linking a series of design decisions that do not explicitly consider profit.the following nine steps are the primary activities that many product development processes accomplish (schmidt et al., 2002):step 1.

24、identify the customer needs.step 2. establish the product specification.step 3. define alternative concepts for a design that meets the specification.step 4. select the most suitable concept.step 5. design the subsystems and integrate them.step 6. build and test a prototype; modify the design as req

25、uired.step 7. design and build the tooling for production.step 8. produce and distribute the product.step 9. track the product during its life cycle to determine its strengths and weaknesses.this list (or any other description that uses a different number of steps) is an extremely simple depiction t

26、hat not only conveys the scope of the process but also highlights the inherent (but unquestioned) decomposition. there are many other ways to represent product development processes and the component tasks, including the use of schedules or a design structure matrix (smith and eppinger, 2001).manufa

27、cturing firms understand that design decisions (though made early in the product life cycle) have an excessive impact on the profitability of a product over its entire life cycle. consequently, product development organizations have created and used concurrent engineering practices for many years (s

28、mith, 1997, provides a historical view). many types of tools and methods (such as cross-functional product development teams and design for manufacturing guidelines) have been created, adopted, and implemented to improve decision-making. cooper (1994) identifies three generations of formal approache

29、s to product development, all of which involve decomposition.it should be noted, however, that decomposition is not the only way to describe product development. as an alternative to decomposing a system design problem into subproblems, hazelrigg (1996) proposes creating and refining system design m

30、odels to express how detailed design variables affect the overall system performance. this approach suggests that a product development process would end with using the model to find the optimal design. hazelrigg (1998) encourages this type of optimization but does not discuss the process of generat

31、ing the profit maximization model.3. a methodology for design for modularitya three-phase methodology is proposed for the development of complex products using the modularity concept 1,2. the proposed methodology matches the criteria set by the design for functionality, assembly and manufacture. som

32、e of the major benefits associated with this methodology include: increased design accuracy, efficiency, and the reuse of existing design for new programs. potential for integration of the developed methodology and technology into the engineering design activities. modular product design and the pro

33、cess of planning the production are integrated in one overall engineering process in which product features are mapped into their feasible process(es) in a one to one correspondence.in order to implement this concept successfully, the manner in which the modules are selected is critical. by establis

34、hing simple interfaces within the modules, the numbers of interactions are then reduced. the steps associated with this methodology include:phase i - decomposition analysis: design for modularity and classification1. product and problem decomposition.2. structural and modular decomposition.3. associ

35、ativity analysis between the components and specification.4. application of group technology classification system.5. construction of the associativity measure matrix.6. optimum selection of modules.phase ii - product analysis: design for assembly and functionality analysis1. identify the components

36、 that could be produced and assembled separately.2. determine of the order of disassembly and assembly for each sub-component module.3. establish the interfaces based on the analysis of the design features.4. determine of the order, which the sub-assemblies are assembled to produce the final product

37、.phase iii - process analysis: design for manufacture1. family identification and template retrieval.2. determination of the logical order of gt codes for the process of modules.3. machine and process parameter calculation.4. variant process planning.4. decomposition analysis: design for modularity

38、and classificationphase i of the methodology further specifications associated with this phase are illustrated as follows:4.1. needs analysis the design engineer is usually given an ill-defined problem. in many situations, the designer has to respond to the mere suggestion that there is a need for a

39、 product to perform a certain function. one of the main tasks is to find out precisely what are the needs and what do customers really want. an important step in the design is to describe the product fully in terms of functional needs and physical limitations. these functional needs and physical lim

40、itations will form the product specifications. surveying prospective purchasers or customers could collect information required to identify customer needs. conducting a marketing study that begins by establishing target markets and customers can do this. then customers wants and needs could be obtai

41、ned by using several methods such as interviews and questionnaires. also, similar products (competitive products) are investigated to find possible improvement opportunities by focusing on weakness points and desired features by customers. next, customer wants and needs are arranged into groups and

42、prioritized according to their importance. needs analysis usually results in a statement of recognized needs and the expected manner in which that need should be met. 4.2. product requirements analysisresults of the needs analysis step are used to identify the product requirements. the development g

43、roup begins by preparing a list of functional objectives needed to meet the customers primary needs. further analysis of customer needs reveals operational functional requirements that impose both functional and physical constraints on the design. secondary customer requirements will be categorized

44、as general functional requirements; they are ranked secondary because they will not affect the main function of the product. that is, a product may lack one or more general functional requirement and still be considered as a functional product that meets the intended function. general functional req

45、uirements should be weighted with respect to their importance.4.3. product concept analysisproduct/concept analysis is the decomposition of the product into its basic functional and physical elements. these elements must be capable of achieving the products functions. functional elements are defined

46、 as the individual operations and transformations that contribute to the overall performance of the product. physical elements are defined as the parts, components, and subassemblies that ultimately implement the products function. product concept analysis consists of product physical decomposition

47、and product functional decomposition. in product physical decomposition, the product is decomposed into its basic physical components which, when assembled together, will accomplish the product function. physical decomposition should result in the identification of basic components that must be desi

48、gned or selected to perform the product function. product functional decomposition describes the products overall functions and identifies components functions. also, the interfaces between functional components are identified. 4.4. product/concept integrationbasic components resulting from the deco

49、mposition process should be arranged in modules and integrated into a functional system. the manner by which components are arranged in modules will affect the product design. the resulting modules can be used to structure the development teams needed. system level specifications are the oneto- one

50、relationship between components with respect to their functional and physical characteristics. functional characteristics are a result of the operations and transformations that components perform in order to contribute to the overall performance of the product. physical characteristics are a result

51、 of the components arrangements, assemblies, and geometry that implement the product function. physical and functional characteristics, forming the system level specifications, are arranged into a hierarchy of descriptions that begins by the component at the top level and ends with the detailed desc

52、riptions at the bottom level.bottom level descriptions (detailed descriptions) are used to determine the relationships between components, 1 if the relationship exists and 0 otherwise. this binary relationship between components is arranged in a vector form, “system level specifications vector”(slsv

53、). system level specifications identified in the previous step affects the general functional requirements in the sense that some specifications may help satisfy some general functional requirements, while other specifications might prevent the implementation of some desired general functional requi

54、rements. the impact of the sls on gfrs should be clearly identified which will help in developing products that will meet, up to a satisfactory degree, the general functional requirements stated earlier. the impact will be determined based on 1 as negative impact, 0 as no impact, and 1 as positive i

55、mpact. a negative impact represents an undesired effect on the general functional requirements such as limiting the degree to which the product will meet the general requirement, or preventing the product from implementing the general requirement. while a positive impact represents a desired effect

56、that the sls will have on the general requirements, such sls will ensure that the product will satisfy the requirements and result in customer satisfaction. an sls is said to have no impact if it neither prevents the implementation of the gfr, nor helps satisfying the gfr.the degree of association b

57、etween components should be measured and used in grouping components into modules. incorporating the general functional requirement weights can do this, in addition to the system level specifications vectors and their impacts on the general functional requirements to provide a similarity index betwe

58、en components.the similarity indices associated with components are arranged in a component vs. component matrix. components with high degree of association should be grouped together in design modules. this can be accomplished by using an optimization model that maximizes the sum of the similaritie

59、s. the optimization model will identify independent modules that can be designed simultaneously. several models are available for optimization analysis of this model.5types of decompositiona product development process follows a decomposition scheme that reflects the experience of the organization and the individuals that inhabit the organization. this relationship explains the design of many organizations and business processes, of cou