Functional Build Gaining Acceptance as Most Efficient Way to Build Auto Bodies
28 September 1999
American Iron and Steel Institute Reports Functional Build Gaining Acceptance as Most Efficient Way to Build Auto Bodies
Automakers Realizing Cost & Time Savings, Better Quality & Performance
DETROIT, Sept. 28 -- Automakers are reducing lead times and
total costs for metal stamping dies and for subsequent assembly of vehicle
bodies by employing an approach known as "functional build," in which
engineers focus on the ultimate functionality of the auto body rather than
trying to ensure that individual body components strictly meet blueprint
specifications.
According to the University of Michigan Transportation Research Institute
(UMTRI), which has been studying functional build approaches and methods that
various carmakers are using to conduct the die tryout phase of design and
production of auto body stamping dies, automakers are reporting results such
as:
* "90 percent time savings on body die tryouts
* "48 percent cost savings on total die program for the body
* "50 percent time and cost savings on tryout and productionizing body
dies
* "$27 million annual steel savings on the body
* "Aggregate savings to the auto industry because of this research is at
least one billion dollars."
Jay Baron, Ph.D., of UMTRI, who has been leading the research, adds,
"Automakers report that they have experienced significant success implementing
functional build in several areas of the car body, such as the engine
compartment, doors, and on entire bodies with more than 150 individual body
panels."
The purpose of functional build is to find the shortest and least costly
path to a dimensionally acceptable body. It is a holistic, common sense
process that says what matters is the fit and functionality of the fully
assembled body. Conversely, it says that strict adherence to making
individual parts comply with blueprints takes longer and costs more and still
may not yield an optimal body.
Functional build helps automakers design and build auto bodies that:
* Save time and cost on die tryout and preparing dies for production
* Achieve higher quality ratings
* Achieve greater crashworthiness.
Time and cost savings and improved performance result from:
* Reduced die rework in the die design phase
* Negligible increase in rework at the production tryout stage
* Earlier and more precise identification of potential problems
* Improved selection of critical dimensional check points
* Creation and maintenance of institutional memory through better
collection and retention of data.
An alternative to functional build is "net build," in which the focus is
on making dimensionally accurate parts to blueprint specifications and then
attempting to assemble them into complete, dimensionally accurate bodies.
"Unfortunately -- and perhaps counter-intuitively -- this method is
expensive and time-consuming," said Baron.
Net build relies on large amounts of dimensional and other data. "If you
look only at data, you end up reworking dies and making more fixes and
adjustments than you need to," he said.
"Functional build seeks functional utility. Some areas of the body do
require dimensional precision, but not all. In functional build, parts are
evaluated by assembling them with their mating parts and deciding if they
achieve functionality," said Baron.
"Japanese manufacturers are using functional build very well. They
initially adapted the concepts from the North Americans," he said.
"Europeans, particularly the German manufacturers, continue to focus on
making each part perfect and then doing whatever it takes to get a
dimensionally precise, complete body. North Americans have tended to rely on
math-based approaches and making each part precisely match the blueprint."
Baron says that successful implementation of functional build is as
dependent on organizational culture and dynamics as it is on technical
aspects.
"Japanese culture of collaboration and cooperation has been very helpful
in their efforts because successful implementation of functional build
strategies requires excellent cooperation among key departments," said Baron.
"Those departments, for example, include die making, stamping, assembly and
product design.
"North American manufacturers have been hindered by organizational
structure and management styles that impede cross-functional cooperation.
But, they are making great progress in relying less strictly on data-driven
approaches and more on subjective criteria, such as design intent and ultimate
customer satisfaction," he said.
"We believe that the optimal functional build approach is somewhere in the
middle between the Japanese and the North Americans," said Baron. "The
Japanese are improving their approach with more data and less reliance on
individual expertise, both of which improve institutional memory. The North
American approach, on the other hand, is improving through greater cooperation
among departments and less strict adherence to blueprint specifications."
American Iron and Steel Institute (AISI) is a non-profit association of
North American companies engaged in the iron and steel industry. The
Institute comprises 47 member companies, including integrated and electric
furnace steelmakers, and 178 associate and affiliate members who are suppliers
to or customers of the steel industry. For a broader look at steel and its
applications, the Institute has its own website at http://www.steel.org .
The Automotive Applications Committee (AAC) is a subcommittee of the
Market Development Committee of AISI and focuses on advancing the use of steel
in the highly competitive automotive market. With offices and staff located
in Detroit, cooperation between the automobile and steel industries has been
significant to its success. This industry cooperation resulted in the
formation of the Auto/Steel Partnership, a consortium of DaimlerChrysler, Ford
and General Motors and the member companies of the AAC.
This release and other steel-related information are available for viewing
and downloading at American Iron and Steel Institute/Automotive Applications
Committee's website at http://www.autosteel.org
Automotive Applications Committee member companies:
AK Steel Corporation
Bethlehem Steel Corporation
Dofasco Inc.
Ispat Inland Inc.
LTV Steel Company
National Steel Corporation
Rouge Steel Company
Stelco Inc.
US Steel Group, a unit of USX Corporation
WCI Steel, Inc.
Weirton Steel Corporation