Design--a multiparameter problem

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Design--a multiparameter problem
Function
Does it work? How reliably? Over what
conditions does it work? Practicality, ease of
use i) the flashing 1200 on a VCR ii) a
recipe that calls for 25 ingredients iii) a
remote-controlled garage door
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Cost a) Market competitiveness b) Return on
investment i) life of product (software for
DOS computers) ii) fragility of
product liquid vs. tablet medicine c)
Manufacturability i) single or multiple steps
in the process ii) multiple sub-assemblies iii
) existence of machinery iv) expected market
(quantity) space shuttle toilet
10 Pentium CPU 10,000,000 d)
Transportability size, weight
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Aesthetics a) visual appeal b) size,
weight i) small and light is good camcorders,
cell phones ii) big and heavy is
good frypans, tools iii) illusion thin
frypans made to look thick plastic car grills
made to look like metal
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Quality control a) Some failures OK screws
without threads a mousetrap that doesnt trip a
floppy disk that wont format b) Failures
not OK space-suits pacemakers c) Zero
defects?
Electrodyne pacemaker, 1958
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Life Expectancy a) single use cameras razor
s British Seagull motors b) outright
failure TV picture tube c) designed to
wear brake pads tires d)
Lifetime artificial hip joint
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Repair a) Throwaway--plastic spoon, hand
mixer b) Fix vs. replace--appliances c)
Length of corporate responsibility--warranty,
parts d) Customer service
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Safety a) safety factor i) percent over
design elevator cable ii)
statistical average loading per square
foot 100 year events b) mode of
failure i) catastrophic--without warning ii)
indicator steels that crack without
failing noise on worn automobile brakes iii)
gradual growling of an old hand mixer
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Packaging a) size b) protection during
transport c) assembled vs. non-assembled d)
completeness--batteries not included
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Environmental
i) pollution during manufacture ii) pollution
during operation iii) pollution during
disposal iv) biodegradation
Sheetrock a biproduct of flue gas desulfurization
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Other a) product certification--e.g., UL
listing b) Versatility i) temperature,
humidity, etc. ii) foreign use--electricity
requirements
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Design Its not a science
its an art.