Page 387 - Design for Six Sigma a Roadmap for Product Development

Design for X 357

typical savings of over 60 percent reduction in work in progress (WIP).
However, the most significant advantages are the high-quality parts
produced improving both the rolled throughput yield (RTY) (by mini-
mizing the effect of hidden factories) and the overall defect per million
occurrences (DPMO) by reducing scrap and rework.
Before embarking on the DFA and DFM tools, the team should

■ Revisit the physical structure, the process structure of the DFSS algo-
rithm (Chap. 5), as well as the marketing strategy. The team should
be aware that the DFSS algorithm as a product design strategy is
global and the process strategy is usually local, depending on the
already existing manufacturing facilities.
■ Review all processes involved in market analysis, customer attrib-
utes and the CTSs, and other requirements such as packaging and
maintenance. Where clarification is sought, the team may develop
necessary prototypes, models, experiments, and simulation to mini-
mize risks. In doing so, the team should take advantage of available
specifications, testing, cost-benefit analysis, and modeling to build
the design.
■ Analyze existing manufacturing and assembly functions, operations,
and sequence concurrently using simulation tools to examine assem-
bly and subassembly definitions of the product and find the best
organization and production methods.
■ Apply the most appropriate, rather than the latest, technology in the
processes identified in the process structure.
■ Follow the axiomatic design approach to create “modular” design,
namely, standard physical entities in the form of components, parts,
and subassemblies. Modular entities have many attractive pros
(advantages), such as cost reduction, physical and process structures
configuration ease, facilitation of engineering change implementa-
tion, more product derivatives, and higher quality and reliability.
■ Design for minimum number of parts by using the idea of physical
coupling, not the functional coupling, namely, multifunctional
requirements parts with multiple DPs uncoupled in time or space.
For example, consider the bottle-can opener in Fig. 10.1 (Suh 1990).

Figure 10.1 Bottle-can opener.