Frontiers of Engineering Reports on Leading Edge Engineering from the 1997 NAE Symposium on Frontiers of Engineering (1998) / Chapter Skim
Currently Skimming:
Decision-Making Tools for Design and Manufacturing
Decision-Making Tools for Design and Manufacturing
Pages 77-88
The Chapter Skim interface presents what we've algorithmically identified as the most significant single chunk of text within every page in the chapter.
Select key terms on the right to highlight them within pages of the chapter.
From page 77... ...
DECISION-MAKING Tools FOR DESIGN AND MANUFACTURING
|
From page 79... ...
In the case of airframes and automotive bodies, fixture design, product decomposition, and assembly methods all affect final product quality (Cunningham et al., 1996; Leyland, 1997~. Ideally, early design stages should focus on making tradeoffs between the cost of the product and the ability to achieve the desired product quality.
|
From page 80... ...
comparing consign alternatives involves evaluating multiple optimization criteria. One layout may have a higher labor content but also higher yield rates; another may have less expensive tooling but lower yield rates.
|
From page 81... ...
KCs are product features, manufacturing process parameters, and assembly features that significantly affect a product's performance, function, and form. KC implementation started in the 1980s and, although these practices are integrated into current design processes in industry, they have been written about predominantly in internal publications (Lee and Thornton, 1 996a,b; Thornton, 1 996a,b)
|
From page 82... ...
The following section provides a simple example of how the KC Lowdown and related costs are used to make a direct comparison between two different assembly options in aircraft design. One approach is a traditional assembly requiring fixtures and the other is a newer approach that employs precision features to locate the parts.
|
From page 83... ...
Table 1 shows cost comparisons of the two options using typical data available from the cost and process capability databases.) CONCLUSION In summary, a set of tools and methods are being developed by the author to predict and mitigate expensive rework, scrap, and repair while balancing other cost drivers in manufacturing processes.
|
From page 84... ...
1996a. Enhanced key characteristics identification methodology for agile design.
|
From page 85... ...
In addition, with processing times growing and multiple products in process at once, simply counting products as they exit the end of the line may distort factory performance for the products still in production. For these complex manufacturing systems, a more rigorous measurement procedure is needed to consider the individual performance measurements of process and product while providing an overall gauge of manufacturing perfor mance.
|
From page 86... ...
By using information from the factory CIM systems, decision analysis allows simultaneous consideration of multiple criteria, such as number of turns, work in process, process yield, queue size, and cycle time at key processes. Preferences are modeled analytically and combined with tradeoff parameters assessed with the certainty equivalent method (Keeney and Raiffa, 1976~.
|
From page 87... ...
1991. Multiattribute evaluation within a present value framework and its relation to the analytic hierarchy process.
|
Key Terms
This material may be derived from roughly machine-read images, and so is provided only to facilitate research.
More
information on Chapter Skim is available.