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2003-01-3055
IMPLEMENTATION OF A PHYSICS-BASED DECISION-MAKING
FRAMEWORK FOR EVALUATION OF THE MULTI-
DISCIPLINARY AIRCRAFT UNCERTAINTY
Simon I. Briceno
Graduate Research Assistant, Aerospace Systems Design Laboratory (ASDL), Georgia Tech
Dimitri N. Mavris
Boeing Professor for Advanced Aerospace Systems Analysis, School of Aerospace Engineering, Director, ASDL
Copyright © 2003 SAE International
ABSTRACT
In today’s business climate, aerospace companies
are more than ever in need of rational methods and
techniques that provide insights as to the best
strategies which may be pursued for increased
profitability and risk mitigation. However, the use of
subjective, anecdotal decision-making remains
prevalent due to the absence of analytical methods
capable of capturing and forecasting future needs.
Negotiations between airframe and engine
manufacturers could benefit greatly from a
structured environment that facilitates efficient,
rational, decision-making. Creation of such an
environment can be developed through a parametric
physics-based, stochastic formulation that uses
Response Surface Equations as meta-models to
expedite the process. This paper describes the
implementation of such an approach in order to
demonstrate the types of insights that might be
gained as an engine manufacturer tries to forecast
the effects of the associated airframe uncertainties
(structural, aerodynamic, etc. design changes) on
engine related characteristics for the design of a
hypothetical regional business jet.
INTRODUCTION
In the present business climate of Wall Street
quarterly profit expectations, product launch
decisions in the aerospace industry can no longer
be based on engineering considerations alone.
Current management processes could greatly
benefit by the presence of a parametric tool that
adequately describes and assesses new projects
and opportunities based on both engineering and
management considerations in an integrated
environment.
In addition, a company cannot afford to base its
decisions on information that does not account for
the inherent uncertainty associated with engineering
assumptions and customer requirements evolution.
The inclusion of financial and competitive factors
also is critical to decision-making. A new paradigm
shift is therefore needed in the industry to facilitate
these types of trade-offs. Although, this discussion
may be pertinent to a variety of business settings,
the authors have selected to study and understand
the complex, at times non-cooperative, customer-
supplier relationship. More specifically, an airframe
and an engine manufacturer were chosen as the
representative customer and supplier, respectively,
in order to formulate and rationalize the elements
needed for the development of one such
environment.
For this hypothetical scenario the engine
manufacturer is assumed to be eager to capitalize
on the opportunity of becoming the first supplier to
successfully design, build and certify a competitive
engine. This is particularly important in this context
as airlines commonly expect their aircraft to be
certified with products from all competing engine
companies. Since this first certification could
ultimately lead to early entry into the market prior to
their competitor and potential profits, engine
manufacturers are often willing to make concessions
to ensure this competitive edge. Therefore, it is the
authors´ belief that engine manufacturers would
especially benefit from the existence of a capability
that allows management to provide some rationale
and certainty in their decision-making process. The
creation of such a framework involves defining key
issues at the outset of the process. Initial steps use
engineering analysis to provide a sense of cost and
product uncertainty for management to consider.