An integrated design and manufacturing approach
allows economic decisions to be made that reflect an entire
system design as a whole. To achieve this objective, we
have developed and utilized integrated cost and engineering
models within a focused design perspective. A framework
for the integrated design of an aircraft system with a
combined performance and economic perspective is described
in this article. This framework is based on the concept
of Design Justification using a Design-for-Economics
approach. We have developed a knowledge-based system that
can be used to evaluate aircraft structural concept material
and process selections. The framework consists of the knowledge-based
system, integrated with numerical analysis tools including
an aircraft performance/sizing code and a life-cycle cost
analysis code. Production cost estimates are applied for
evaluation of process trades at the subcomponent level
of design. Life-cycle cost estimates are used for evaluation
of process trades at the system level. Results of a case
study are presented for several advanced wing structural
concepts for a future supersonic commercial transport aircraft.
Cost versus performance studies indicate that a high-speed
civil transport aircraft with a hybrid wing structural
concept, though more expensive to manufacture than some
homogeneous concepts, can have lower direct operating costs
due to a lower take-off gross weight and less mission fuel
required.