Chapter 4 Researching Designs 67
Lisa S./Shutterstock.comkttt/Sh Li S
Figure 4-15.
Engineers consider
the capabilities of their
CNC equipment to
manufacture a specific
product.
Effectiveness Research
Effectiveness is the level at which an engi-
neer’s design meets the intended outcome or
effect. One use of experimental research is to
determine if the idea will work with all of the
considerations of production, cost effectiveness,
and use of specifi c materials. Engineers will
perform experiments to determine if the basic
idea will work. These early experiments do not
always use the actual materials anticipated in the
design, but they may use models to illustrate the
idea while the research and other experiments
provide information on the materials, cost effi -
ciency, and production possibilities.
Structural engineers may produce a model
bridge to test the effectiveness of their design. By
using scaled materials and the appropriate scaled
weight, they can simulate the effectiveness of the
bridge through an experiment. Chemical engi-
neers may test combinations of different chemi-
cals to produce a new type of lubricating fl uid for
a hydraulic chamber. At this stage, the chemical
engineer may make sure the chemicals will bond
together as anticipated so the solution can be
developed further. The tests this early in the engi-
neering design process are typically designed to
ensure the idea is a real and workable potential
solution to the problem.
Trade-Offs
Once the engineers have performed the initial
historical and experimental research for potential
solutions, they begin the solution creation step.
The engineers begin by analyzing the advantages
and disadvantages of each approach. Each solu-
tion will have good and bad components and it
is the job of the engineer to consider all of these
strengths and weaknesses to determine which of
the designs will be most benefi cial. The engineer
performs a trade-off analysis by looking at all the
strengths and weaknesses of each design.
A trade-off is the consideration that gain-
ing one positive quality in a design means you
lose one other quality. This compromise is a
challenge for engineers to determine the best
solution. Engineers use a trade-off chart to
analyze the potential trade-offs of each solu-
tion. The trade-off chart is different for each
problem, but there are similarities among all
charts. Each chart lists different characteris-
tics important for the design and the engineer
rates the appropriateness of each quality to
the overall design solution. The trade-off chart
provides the engineer with a way to measure
which design is the best fit for the problem.
Common considerations for the chart are listed
on the next page but can be different with each