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3 Integrated Product and Process Design
Pages 60-83

The Chapter Skim interface presents what we've algorithmically identified as the most significant single chunk of text within every page in the chapter.
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From page 60...
... As described in Chapter 1, a comprehensive IPPD system would include integration of performance specifications, conceptual design, detailed design, manufacture, and assembly, together with the ability to simulate actual use, field 60
From page 61...
... However, an important first step toward this vision can be achieved by joining detailed design with manufacturing and assembly. To accomplish this requires a new level of information structuring and integration.
From page 62...
... This evolution of the design system will be fueled by experience with its core implementation; feedback from users will determine what new capabilities it needs. DESIGN PARADIGMS Electronic Design Of all the different types of design for discrete manufacturing, the design of very large scale integrated (VLSI)
From page 63...
... The amount of detail needed in each step of electronic design is appropriate for the work to be performed at that step, thus allowing, for example, the three-dimensional characteristics of a chip to be virtually ignored until the final step of the detailed design process. Central to these design abstractions are languages that describe electronic products at many levels of abstraction (e.g., Verilog HDL)
From page 64...
... However, the design rules associated with library cells and macros and the tools that enforce adherence to these rules enable a designer to treat library components as parts that can be connected without concern for issues such as back-loading. A close relationship between the fabrication processes and the extent to which the actual product matches the original design.
From page 65...
... Using today's design tools, an expert electronic designer engaged in fully customized design can reasonably hope to complete the necessary design work on a few hundred transistors in a single day of work; such work includes the detailed design, debugging, and documentation needed for a commercial product. For example, the Pentium processor (order of magnitude 5 million transistors)
From page 66...
... . mshng mech~ica1 designs 1ba1 arc compile in power 10 Lose avaN~le for me analogous electronic design task.
From page 67...
... In electronic design, many sophisticated tools have been developed to support physical aspects of design, while fewer tools exist for aspects of conceptual design such as requirement gathering or architectural decision making.
From page 68...
... The committee believes that concentrating on the areas described in the rest of this chapter will yield the most significant benefits to the IPPD process in the short to medium term. Other areas in the IPPD process not described in this chapter (mostly in the conceptual design area will be advanced in the short to medium term by better communication capabilities and by better and additional access to data.
From page 69...
... . descriptions Resource description models Accommodation of spatial and temporal dimensions of processes Easy, error-free configuration control at the selling or servicing stage Manufacturing of a robust final product from parts obtained from different sources Data descriptions for many physical processes and entities in a unified form Descriptions of design interactions, analyses, and process steps integrated with product geometry and function descriptions Data visualization Database searching using geometric features, performance criteria, or process descriptions Intelligent advisors Visualization tools Systems that capture corporate memory and knowledge Systems that support corporate learning Techniques for handling data legacy issues Systems that record design history and rationale
From page 70...
... provide a more formal language, EXPRESS, for use as a data description language in which data models are described. EXPRESS allows the modeler to capture some of the semantics of the data by explicitly recognizing relationships between data elements along with the cardinality of such relationships and by capturing constraints between data elements.
From page 72...
... 17-19. It recommends research on product and process design, including data structures for describing products in terms of conceptual design, functional features, dimensions and tolerances, manufacturable features, and so forth, and methods that allow such structures to be interfaced with other computer-integrated manufacturing components, such as knowledge-based systems.
From page 73...
... While different computer-aided tools for design are based on different data models, much of the content of these models is overlapping. As more computational support for design comes on-line, engineers will rely 7 A 1991 NRC report recommends research on tolerance analysis, tolerance representations, tolerance-perforrnance relationships, and tolerance standards and measurement methods.
From page 74...
... ~\ ~F Fag ~ lIllllllIllllIllllll~llIl~llllIIll ~III~llIll increasingly OD in~abon models lo help bridge the gap bet~cen mulUdisciplin~ users of diverse tools; c~chan~c~lc Comic models arc Bus ~ p~icul~ly pressing need. Success in developing c~ch=gc~le reprcscutadons of pc~ancc, gcomc~y, and process requircmcnts is ~ prcrequishc far their use in design tools and by practhioncrs in 1hc alUcd domains of process cquipmcn1 design and shop door planing Id oporabons, as loch as by designers in odor companies or in odor technical domains.
From page 75...
... Design tools for electronic devices typically do not provide information about fabrication cost, because the cost of fabricating a given chip is approximately independent of what is put on it.8 But this is not true for mechanical design, in which design choices may have a significant impact on the cost of making the final product. Designers need to be able to keep such high-level trade-offs constantly in mind through the use of better design tools.
From page 76...
... Process descriptions will also be used to enhance product design, so that by simulation the best process can be matched to the product design (and vice versa) for maximum economic advantage (or to satisfy whatever criteria-such as quality or time to delivery are important for the particular case)
From page 77...
... Courtesy of Nippondenso. for representing processes in sufficient detail and with enough specificity to make the process description adequately complete and unambiguous.9 Such formalisms allow designers to describe, enforce, and simulate processes, including fac 9 Of course, at the root of a good process description is a good scientific and engineering understanding of the specific process involved the best tools to formalize process description are not helpful if the knowledge base they are used to formalize is shaky and uncertain.
From page 78...
... Research needs in the area of process description include: · A language for expressing process descriptions thatfacilitates checking for correctness and completeness and the capability to express not only nominal process behavior but also variant behavior. Such a language must also be translatable across technical domains.
From page 79...
... Few tools exist for creating, monitoring, and guiding the design process itself, except for familiar project management tools like PERT. (PERT is largely a schedule and resource management tool.)
From page 80...
... Research Areas Not Specific to Manufacturing Geometric Reasoning A generic intellectual activity required by mechanical design is geometric reasoning. A major difference between VLSI design and mechanical design is i2 Because such understanding is often proprietary to component suppliers, research in this and similar areas of collaborative design must consider nontechnical issues such as intellectual property rights and intercompany data exchange.
From page 81...
... Ultimately, the design environment should support improved visualization tools or other design aids that will help make geometric reasoning faster and efficiently achievable by a broader range of people. In addition, tools that undertake geometric reasoning automatically (i.e., without relying on a skilled human)
From page 82...
... · To what extent can a product description for mechanical items be converted automatically into a production plan, that is, a sequence of fabrication steps that transform raw materials into a final product? · Can a general process description language be developed that would be both man- and machine-intelligible, permitting processes to be described more precisely than is possible now?
From page 83...
... · Similarly, what new languages or data structures can be developed to better describe process requirements, such as performance, cost, reliability, ease of diagnosis and repair, material handling, ease of use, and ease of modification? · What new data logging and correlation methods can be devised that would help the process of continuous improvement, such as finding multiple occurrences of the same type of machine failure or deducing what is the best sequence for testing a broken system to diagnose its problems?


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