外文翻譯--藝規(guī)程制訂與并行工程

1、<p><b>　　英文原文</b></p><p>　　Process Planning and Concurrent Engineering</p><p>　　Process Planning </p><p>　　Process planning involves determining the most appropriat

2、e manufacturing and assembly processes and the sequence in which they should be accomplished to produce a given part or product according to specifications set forth in the product design documentation. The scope and var

3、iety of processes that can be planned are generally limited by the available processing equipment and technological capabilities of the company of plant. Parts that cannot be made internally must be purchased from outsid

4、e v</p><p>　　Process planning is usually accomplished by manufacturing engineers. The process planner must be familiar with the particular manufacturing processes available in the factory and be able to inte

5、rpret engineering drawings. Based on the planner’s knowledge, skill, and experience, the processing steps are developed in the most logical sequence to make each part. Following is a list of the many decisions and detail

6、s usually include within the scope of process planning.</p><p>　　.Interpretation of design drawings.  The part of product design must be analyzed (materials, dimensions, tolerances, surface finished, et

7、c.) at the start of the process planning procedure.</p><p>　　.Process and sequence.  The process planner must select which processes are required and their sequence. A brief description of processing st

8、eps must be prepared.</p><p>　　.Equipment selection.  In general, process planners must develop plans that utilize existing equipment in the plant. Otherwise, the component must be purchased, or an inve

9、stment must be made in new equipment.</p><p>　　.Tools, dies, molds, fixtures, and gags.  The process must decide what tooling is required for each processing step. The actual design and fabrication of t

10、hese tools is usually delegated to a tool design department and tool room, or an outside vendor specializing in that type of tool is contacted.</p><p>　　.Methods analysis.  Workplace layout, small tools

11、, hoists for lifting heavy parts, even in some cases hand and body motions must be specified for manual operations. The industrial engineering department is usually responsible for this area.</p><p>　　.Work

12、standards.  Work measurement techniques are used to set time standards for each operation.</p><p>　　Cutting tools and cutting conditions.  These must be specified for machining operations, often wi

13、th reference to standard handbook recommendations.</p><p>　　Process planning for parts</p><p>　　For individual parts, the processing sequence is documented on a form called a route sheet. Just a

14、s engineering drawings are used to specify the product design, route sheets are used to specify the process plan. They are counterparts, one for product design, the other for manufacturing.</p><p>　　A typica

15、l processing sequence to fabricate an individual part consists of: (1) a basic process, (2) secondary processes, (3) operations to enhance physical properties, and (4) finishing operations. A basic process determines the

16、 starting geometry of the work parts. Metal casting, plastic molding, and rolling of sheet metal are examples of basic processes. The starting geometry must often be refined by secondary processes, operations that transf

17、orm the starting geometry (or close to final geometr</p><p>　　Once the geometry has been established, the next step for some parts is to improve their mechanical and physical properties. Operations to enhanc

18、e properties do not alter the geometry of the part; instead, they alter physical properties. Heat treating operations on metal parts are the most common examples. Similar heating treatments are performed on glass to prod

19、uce tempered glass. For most manufactured parts, these property-enhancing operations are not required in the processing sequence.</p><p>　　Finally finish operations usually provide a coat on the work parts (

20、or assembly) surface. Examples included electroplating, thin film deposition techniques, and painting. The purpose of the coating is to enhance appearance, change color, or protect the surface from corrosion, abrasion, a

21、nd so forth. Finishing operations are not required on many parts; for example, plastic molding rarely require finishing. When finishing is required, it is usually the final step in the processing sequence.</p><

22、;p>　　Processing Planning for Assemblies</p><p>　　The type of assembly method used for a given product depends on factors such as: (1) the anticipated production quantities; (2) complexity of the assembled

23、 product, for example, the number of distinct components; and (3) assembly processes used, for example, mechanical assembly versus welding. For a product that is to be made in relatively small quantities, assembly is usu

24、ally performed on manual assembly lines. For simple products of a dozen or so components, to be made in large quantities, aut</p><p>　　Process planning for assembly involves development of assembly instructi

25、ons, but in more detail .For low production quantities, the entire assembly is completed at a single station. For high production on an assembly line, process planning consists of allocating work elements to the individu

26、al stations of the line, a procedure called line balancing. The assembly line routes the work unit to individual stations in the proper order as determined by the line balance solution. As in process planning</p>

27、<p>　　Make or Buy Decision</p><p>　　An important question that arises in process planning is whether a given part should be produced in the company’s own factory or purchased from an outside vendor, and

28、 the answer to this question is known as the make or buy decision. If the company does not possess the technological equipment or expertise in the particular manufacturing processes required to make the part, then the an

29、swer is obvious: The part must be purchased because there is no internal alternative. However, in many cases, the </p><p>　　In our discussion of the make or buy decision, it should be recognized at the outse

30、t that nearly all manufactures buy their raw materials from supplies. A machine shop purchases its starting bar stock from a metals distributor and its sand castings from a foundry. A plastic molding plant buys its moldi

31、ng compound from a chemical company. A stamping press factory purchases sheet metal either fro a distributor or direct from a rolling mill. Very few companies are vertically integrated in their pro</p><p>　　

32、There are a number of factors that enter into the make or buy decision. One would think that cost is the most important factor in determining whether to produce the part or purchase it. If an outside vendor is more profi

33、cient than the company’s own plant in themanufacturing processes used to make the part, then the internal production cost is likely to be greater than the purchase price even after the vendor has included a profit. Howev

34、er, if the decision to purchase results in idle equipment an</p><p>　　The quoted price for a certain part is $20.00 per unit for 100 units. The part can be produced in the company’s own plant for $28.00. The

35、 components of making the part are as follows:</p><p>　　Unit raw material cost = $8.00 per unit</p><p>　　Direct labor cost =6.00 per unit </p><p>　　Labor overhead at 150%=9.00 per u

36、nit </p><p>　　Equipment fixed cost =5.00 per unit </p><p>　　________________________________</p><p>　　Total =28.00 per unit </p><p>　　Should the component by bought or

37、made in-house?</p><p>　　Solution: Although the vendor’s quote seems to favor a buy decision, let us consider the possible impact on plant operations if the quote is accepted. Equipment fixed cost of $5.00 is

38、 an allocated cost based on investment that was already made. If the equipment designed for this job becomes unutilized because of a decision to purchase the part, then the fixed cost continues even if the equipment stan

39、ds idle. In the same way, the labor overhead cost of $9.00 consists of factory space, utility, an</p><p>　　Make or buy decision are not often as straightforward as in this example. A trend in recent years, e

40、specially in the automobile industry, is for companies to stress the importance of building close relationships with parts suppliers. We turn to this issue in our later discussion of concurrent engineering.</p>&l

41、t;p>　　Computer-aided Process Planning</p><p>　　There is much interest by manufacturing firms in automating the task of process planning using computer-aided process planning (CAPP) systems. The shop-train

42、ed people who are familiar with the details of machining and other processes are gradually retiring, and these people will be available in the future to do process planning. An alternative way of accomplishing this funct

43、ion is needed, and CAPP systems are providing this alternative. CAPP is usually considered to be part of computer-aided man</p><p>　　.Process rationalization and standardization.  Automated process plan

44、ning leads to more logical and consistent process plans than when process is done completely manually. Standard plans tend to result in lower manufacturing costs and higher product quality.</p><p>　　.Increas

45、ed productivity of process planner.  The systematic approach and the availability of standard process plans in the data files permit more work to be accomplished by the process planners.</p><p>　　.Reduc

46、ed lead time for process planning.  Process planner working with a CAPP system can provide route sheets in a shorter lead time compared to manual preparation.</p><p>　　.Improved legibility.  Comput

47、er-prepared rout sheets are neater and easier to read than manually prepared route sheets.</p><p>　　.Incorporation of other application programs.  The CAPP program can be interfaced with other applicati

48、on programs, such as cost estimating and work standards.</p><p>　　Computer-aided process planning systems are designed around two approaches. These approaches are called: (1) retrieval CAPP systems and (2) g

49、enerative CAPP systems .Some CAPP systems combine the two approaches in what is known as semi-generative CAPP.</p><p>　　Concurrent Engineering and Design for Manufacturing</p><p>　　Concurrent en

50、gineering refers to an approach used in product development in which the functions of design engineering, manufacturing engineering, and other functions are integrated to reduce the elapsed time required to bring a new p

51、roduct to market. Also called simultaneous engineering, it might be thought of as the organizational counterpart to CAD/CAM technology. In the traditional approach to launching a new product, the two functions of design

52、engineering and manufacturing engineering tend </p><p>　　Fig.(1). Comparison: (a) traditional product development cycle and (b) product development using concurrent engineering</p><p>　　By contr

53、ast, in a company that practices concurrent engineering, the manufacturing engineering department becomes involved in the product development cycle early on, providing advice on how the product and its components can be

54、designed to facilitate manufacture and assembly. It also proceeds with early stages of manufacturing planning for the product. This concurrent engineering approach is pictured in Fig.(1).(b). In addition to manufacturing

55、 engineering, other function are also involved in th</p><p>　　Concurrent engineering includes several elements: (1) design for several manufacturing and assembly, (2) design for quality, (3) design for cost,

56、 and (4) design for life cycle. In addition, certain enabling technologies such as rapid prototyping, virtual prototyping, and organizational changes are required to facilitate the concurrent engineering approach in a co

57、mpany.</p><p>　　Design for Manufacturing and Assembly</p><p>　　It has been estimated that about 70% of the life cycle cost of a product is determined by basic decisions made during product desig

58、n. These design decisions include the material of each part, part geometry, tolerances, surface finish, how parts are organized into subassemblies, and the assembly methods to be used. Once these decisions are made, the

59、ability to reduce the manufacturing cost of the product is limited. For example, if the product designer decides that apart is to be made of an alumi</p><p>　　Term used to describe such attempts to favorably

60、 influence the manufacturability of a new product are design for manufacturing (DFM) and design for assembly(DFA). Of course, DFM and DFA are inextricably linked, so let us use the term design for manufacturing and assem

61、bly (DFM/A). Design for manufacturing and assembly involves the systematic consideration of manufacturability and assimilability in the development of a new product design. This includes: (1) organizational changes and (

62、2) design pr</p><p>　　.Organizational Changes in DFM/A.  Effective implementation of DFM/A involves making changes in a company’s organization structure, either formally or informally, so that closer in

63、teraction and better communication occurs between design and manufacturing personnel. This can be accomplished in several ways: (1)by creating project teams consisting of product designers, manufacturing engineers, and o

64、ther specialties (e.g. quality engineers, material scientists) to develop the new product design; (2</p><p>　　Process Planning and Concurrent Engineering</p><p>　　T. Ramayah and Noraini Ismail&l

65、t;/p><p><b>　　ABSTRACT</b></p><p>　　The product design is the plan for the product and its components and subassemblies. To convert the product design into a physical entity, a manufact

66、uring plan is needed. The activity of developing such a plan is called process planning. It is the link between product design and manufacturing. Process planning involves determining the sequence of processing and assem

67、bly steps that must be accomplished to make the product. In the present chapter, we examine processing planning and several related</p><p>　　Process Planning </p><p>　　Process planning involves

68、determining the most appropriate manufacturing and assembly processes and the sequence in which they should be accomplished to produce a given part or product according to specifications set forth in the product design d

69、ocumentation. The scope and variety of processes that can be planned are generally limited by the available processing equipment and technological capabilities of the company of plant. Parts that cannot be made internall

70、y must be purchased from outside v</p><p>　　Process planning is usually accomplished by manufacturing engineers. The process planner must be familiar with the particular manufacturing processes available in

71、the factory and be able to interpret engineering drawings. Based on the planner’s knowledge, skill, and experience, the processing steps are developed in the most logical sequence to make each part. Following is a list o

72、f the many decisions and details usually include within the scope of process planning.</p><p>　　.Interpretation of design drawings.  The part of product design must be analyzed (materials, dimensions, t

73、olerances, surface finished, etc.) at the start of the process planning procedure.</p><p>　　.Process and sequence.  The process planner must select which processes are required and their sequence. A bri

74、ef description of processing steps must be prepared.</p><p>　　.Equipment selection.  In general, process planners must develop plans that utilize existing equipment in the plant. Otherwise, the componen

75、t must be purchased, or an investment must be made in new equipment.</p><p>　　.Tools, dies, molds, fixtures, and gages.  The process must decide what tooling is required for each processing step. The ac

76、tual design and fabrication of these tools is usually delegated to a tool design department and tool room, or an outside vendor specializing in that type of tool is contacted.</p><p>　　.Methods analysis.

77、0; Workplace layout, small tools, hoists for lifting heavy parts, even in some cases hand and body motions must be specified for manual operations. The industrial engineering department is usually responsible for this ar

78、ea.</p><p>　　.Work standards.  Work measurement techniques are used to set time standards for each operation.</p><p>　　Cutting tools and cutting conditions.  These must be specified fo

79、r machining operations, often with reference to standard handbook recommendations.</p><p>　　Process planning for parts</p><p>　　For individual parts, the processing sequence is documented on a f

80、orm called a route sheet. Just as engineering drawings are used to specify the product design, route sheets are used to specify the process plan. They are counterparts, one for product design, the other for manufacturing

81、.</p><p>　　A typical processing sequence to fabricate an individual part consists of: (1) a basic process, (2) secondary processes, (3) operations to enhance physical properties, and (4) finishing operations

82、. A basic process determines the starting geometry of the work parts. Metal casting, plastic molding, and rolling of sheet metal are examples of basic processes. The starting geometry must often be refined by secondary p

83、rocesses, operations that transform the starting geometry (or close to final geometr</p><p>　　Once the geometry has been established, the next step for some parts is to improve their mechanical and physical

84、properties. Operations to enhance properties do not alter the geometry of the part; instead, they alter physical properties. Heat treating operations on metal parts are the most common examples. Similar heating treatment

85、s are performed on glass to produce tempered glass. For most manufactured parts, these property-enhancing operations are not required in the processing sequence.</p><p>　　Finally finish operations usually pr

86、ovide a coat on the work parts (or assembly) surface. Examples included electroplating, thin film deposition techniques, and painting. The purpose of the coating is to enhance appearance, change color, or protect the sur

87、face from corrosion, abrasion, and so forth. Finishing operations are not required on many parts; for example, plastic molding rarely require finishing. When finishing is required, it is usually the final step in the pro

88、cessing sequence.</p><p>　　Processing Planning for Assemblies</p><p>　　The type of assembly method used for a given product depends on factors such as: (1) the anticipated production quantities;

89、 (2) complexity of the assembled product, for example, the number of distinct components; and (3) assembly processes used, for example, mechanical assembly versus welding. For a product that is to be made in relatively s

90、mall quantities, assembly is usually performed on manual assembly lines. For simple products of a dozen or so components, to be made in large quantities, aut</p><p>　　Process planning for assembly involves d

91、evelopment of assembly instructions, but in more detail .For low production quantities, the entire assembly is completed at a single station. For high production on an assembly line, process planning consists of allocati

92、ng work elements to the individual stations of the line, a procedure called line balancing. The assembly line routes the work unit to individual stations in the proper order as determined by the line balance solution. As

93、 in process planning</p><p>　　Make or Buy Decision</p><p>　　An important question that arises in process planning is whether a given part should be produced in the company’s own factory or purch

94、ased from an outside vendor, and the answer to this question is known as the make or buy decision. If the company does not possess the technological equipment or expertise in the particular manufacturing processes requir

95、ed to make the part, then the answer is obvious: The part must be purchased because there is no internal alternative. However, in many cases, the </p><p>　　In our discussion of the make or buy decision, it s

96、hould be recognized at the outset that nearly all manufactures buy their raw materials from supplies. A machine shop purchases its starting bar stock from a metals distributor and its sand castings from a foundry. A plas

97、tic molding plant buys its molding compound from a chemical company. A stamping press factory purchases sheet metal either fro a distributor or direct from a rolling mill. Very few companies are vertically integrated in

98、their pro</p><p>　　There are a number of factors that enter into the make or buy decision. One would think that cost is the most important factor in determining whether to produce the part or purchase it. If

99、 an outside vendor is more proficient than the company’s own plant in themanufacturing processes used to make the part, then the internal production cost is likely to be greater than the purchase price even after the ven