2. Evaluation - Controlled Convergence vs.
Weighting and Rating Weighting and Rating Matrix
• Produced our final concept
• More logic and mathematical calculation
involved
• Incorporates the users’ preferences in
terms of features available
• Need to refer to PDS more than controlled
convergence matrix
Controlled Convergence Matrix
• Narrowed down our choice of
concepts
• Involved a lot of personal opinion
• Can achieve a better idea of
performance compared to
competitors
• Allows comparison against another
product
Group Practical Logical Quick Outcome
YES PRACTICAL
COMPARISON
YES NO MORE
IMPARTIAL
Group Practical Logical Quick Outcome
YES PRACTICAL
COMPARISON
YES QUICKERTHAN
WEIGHTING AND
RATING
COULD HAVE BEEN
IMPROVED
3. Evaluation – Dot sticking
• Quick and easy to use
• More successful when used with scamper and
force fitting techniques to add or change features
within concepts
• Allows for more creativity development within
concept evaluation
• All based on personal opinion – risk of ‘following
the crowd’ and pushing through of ideas
Group Practical Logical Quick Outcome
YES and
NO
PRACTICAL
andTHEORY
NO YES PERSONALOPINION
4. Design for Safety and Reliability - FMEA
Part Function Potential Failure Mode Potential Effects of Failure Mode
Severi
ty Potential Causes of Failure
Occurr
ence Detection Prevention
Detect
ion RPN Actions
Ear Covers
Provides a means of playing music to be
heard by the user Hearing damage caused by loud music Causes permanent hearing loss in user 8
The need to play music at a very loud
level 3 NONE DESIGN MARGIN 7 168
Have a warning when music
is at damaging levels -
constant beeping
Plastic covering snaps/cracks Cuts user's finger, speakers stop working 4
Bad material choice, insufficient
material strength 5 VISUAL INSPECTION DESIGN MARGIN 6 120
Use strong, thermosetting
plastic
Speakers stop working correctly Headphones become useless 3Bad design 7
BAD QUALITY DURING
USE TESTING 9 189 Buy-in high quality speakers
Noise flip switch sticks Headphones become useless 3Wear, repetitive use 3 NONE
TESTING, DESIGNED
PREVENTION 5 45
Connection to headband snaps Cuts user, headphones become useless 4
Bad material choice, insufficient
material strength 2 NONE DESIGN MARGIN 7 56
Padding becomes loose and becomes
lodged in the ear Causes temporary/permanent damage to the ear 6
Bad material choice, manufacturing
mistake 8 VISUAL INSPECTION TESTING 8 384 Put a cover over the padding
Connection between covers and
headband is no longer tight and simply
falls out Headphones become useless 3Wear, repetitive use 6 INSPECTION TESTING 4 72
A young child chokes on padding Child stops breathing temporarily, causes death 10
Bad material choice, manufacturing
mistake 3 NONE
DESIGN, MATERIAL
CHOICE 10 300
Place a cover over the
padding
Telescopic headband
Secures the headphones to the head of the
user Padding falls off
Headphones don't make secure connection with
head 2Manufacturing mistake 7 VISUAL INSPECTION TESTING 7 98
Sliding mechanism sticks Headphones will no longer be compact 1Wear, repetitive use 3 INSPECTION TESTING 4 12
Surface becomes scratched and cracked Looks bad, causes small injury, collects germs 4
Bad material choice, insufficient design
for use 2 VISUAL INSPECTION DESIGN MARGIN 5 40
A small child's finger becomes trapped
in sliding mechanism Causes injury, causes loss of finger 8Bad design 2 NONE DESIGN MARGIN 10 160
No physical gap between
sliding parts
Hair becomes trapped in sliding
mechanism Causes pain 5
Bad design, telescopic fails to lock in
place 6 NONE DESIGN MARGIN 10 300
No physical gap between
sliding parts
Spring wire
Provides a connection between the
headphones and the audio device Wire snaps Headphones become useless 3Defect in wire 8 VISUAL INSPECTION
TESTING, DESIGN
MARGIN 7 168 Buy-in high quality wire
Person wraps wire around their finger
Reduces blood flow in finger, causes loss of
finger 8Incorrect use of product 7 NONE
DESIGN, MATERIAL
CHOICE 10 560
Warn of incorrect use on
packaging
Wire gets caught around neck while
cycling Results in strangulation, causes death 10Wire is too long 3 NONE DESIGN 10 300 Reduce the length of the wire
Wire gets tangled on the seat belt in a
car
User also becomes tangled, could cause
strangulation 10Wire is too long 3 NONE
DESIGN, MATERIAL
CHOICE 10 300 Reduce the length of the wire
Wire snaps at volume control Headphones become useless 3Defect in wire 8 VISUAL INSPECTION
TESTING, DESIGN
MARGIN 6 144 Buy-in high quality wire
Jack and MP3 connection Connects the wire to the audio device
Wire snaps at connection between wire
and jack Headphones become useless 3Defect in wire, insufficient strength 8 VISUAL INSPECTION
TESTING, DESIGN
MARGIN 4 96
Connection between jack and audio
device snaps
Headphones become useless, audio device also
gets broken 4Defect 2 VISUAL INSPECTION TESTING 7 56
Jack and MP3 become water logged Could cause small electric shock 8
Bad design, insufficient protection
from water 3 NONE DESIGN 8 192 Provide a waterproof cover
• A good overview of problems
which may occur when the
product is being used by its
intended end user, does not give
any detail about problems which
may occur during the
manufacturing or design process
• Highlights areas which may have
been otherwise neglected
• Needs expertise to identify the
current detection/prevention
which is being implemented
• Can be completed more quickly
if one person carries out the task
instead of a group discussion
• Surprisingly good tool for
innovation and creativity
Ear
Covers
Provides a
means of
playing music
to be heard by
the user
Hearing
damage
caused by loud
music
Causes
permanent
hearing loss in
user 8
The need to
play music at a
very loud level 3NONE
DESIGN
MARGIN 7
16
8
Have a
warning
when
music is at
damaging
levels -
constant
beeping
Plastic
covering
snaps/cracks
Cuts user's finger,
speakers stop
working 4
Bad material
choice,
insufficient
material
strength 5
VISUAL
INSPECTI
ON
DESIGN
MARGIN 6120
Use strong,
thermosett
ing plastic
Group Practical Logical Quick Outcome
YES and
NO
THEORY NO NO TOP-LEVEL
OVERVIEW
5. Design for Safety and Reliability – Root
Cause Analysis • Produces a very
thorough overview
of one problem
• Would be beneficial
to the design
process if every
problem highlighted
in the FMEA chart
was analised like this
• Takes a very long
time to complete
• Outcome could have
been improved if
experts from each
major category had
collaborated to
produce the diagram
– would have
delivered a more
knowledgible,
accurate outcome.
Group Practical Logical Quick Outcome
NO RESEARCH
andTHEORY
YES NO OPPORTUNITYTO
BE IMPROVED
6. Design for Manufacture and Assembly -
ValueAnalysis vs.Value Engineering
Value Analysis
• Develops thoughts of manufacture
and assembly during the design stage
• Could be used as a comparative with
existing products as a form of
evaluation
• More visual output, easier to use
• Takes a while to complete, finding
costs can be difficult and can incur
errors
Value Engineering
• Takes the innovative design ideas
and makes them achievable –
thoughts and ideas on how the
product will fit together
• More robust design achieved
because thought is given to
components and parts
Group Practical Logical Quick Outcome
NO RESEARCH
andTHEORY
YES NO VALUABLE
INFORMATION
Group Practical Logical Quick Outcome
YES IDEA
GENERATION
NO QUICKERTHAN
VALUEANALYSIS
COULD HAVE BEEN
IMPROVED
7. Design for Manufacture and Assembly
Group Practical Logical Quick Outcome
YES RESEARCH and
IMPLEMENTATION
YES NO GOODVISUALAID
FORWHAT HAD
BEENACHIEVED
THROUGHVA AND
VE
8. End of life Product Strategy – General
DFE guidelines vs. Life CycleAnalysis
• Still leaves room for innovation,
however results can be very similar
• Can take a long time to complete
• Driven by goals set by the designer
– ensure the goals of the project are
achieved
• Can be repetitive
• Usually produced the same results
as DFE guidelines process
• Good to take a different viewpoint
and concentrate on the
environment instead of basing
everything purely on users’ needs
• Takes a long time to process
• Produces a very inclusive product
Group Practical Logical Quick Outcome
Better for
continuity if it is
done individually
IDEA GENERATION
and RESEARCH
YES NO REPETITIVE,
POINTS FOR
PDS
Group Practical Logical Quick Outcome
Better for
continuity if it is
done individually
IDEA GENERATION
and RESEARCH
YES NO REPETITIVE,
VISUAL
9. End of Life Product Strategy - Outcomes
• Outcome – made the concept
more recyclable, achieved at
the concept stage by using
different materials and making
it easier to assemble.
• Makes the entire disposal stage
easier and ensures this stage is
incorporated in the design from
the beginning
• The graphs shows
the impacts of the
product at different
stages during the
design process.
10. • Regular weekly meetings on a Tuesday afternoon
• Extra meetings when required
• ‘TO DO LIST’ – shared amongst group
• Deadlines for method/task completion emailed to
members
• Use of Facebook and email to share information
Project Management
