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In this final episode of the online classroom
we're going to look at at system evaluation in particular
the evaluation matrix to help us decide which
design we going to go with this is the final episode of the systems approach to
a straightforward problem
keeping a lawn neat. System evaluation
is really a process for decision-making. Now that you've designed a system
we can revisit your customer requirements and evaluate the best
option for your design
there are many types of evaluation criteria
you can rank them directly or using away team
you could go through a systematic elimination of designs that don't meet
certain criteria
you could do a comparison across alternatives see could be picking the
best Ive
the options that are available to you where you could be comparing across a
standard
you could also apply some mathematical techniques such as the a-plus criterion
and Maxime in Adamek c-max criterion or the her ex
criteria will look at those in more detail in engineering triple 26
for the purposes evaluation today
we're gonna take the way to drinking option and look at a comparison across
the standard
room for the house of quality when now looking at the areas in red
set benchmarks and targets provide assed and ***
and the comparisons are gonna be across three design alternatives
the three design alternatives that I've chosen
are petrol lawnmower and electric lawnmower
and menu lorna you could choose to evaluate just fun
aspect of the design such as the cutting system or the whole design
in your project you could put your design up against other alternatives
the key idea in the evaluation process and systems engineering
is it should be based on all the previous steps he have done
for your project if we go back and remember our customer requirements
we decided design requirements based on those customer requirements
so when I'm saying we're looking for the one that makes the cuts grass
requirement the best
I'm really looking at which has the most effective cutting mechanism
catches cross appropriately and is safe for use as a possible I
your customers probably signed off on these design requirements early on in
the project so it's best the stick with these when you're evaluating your design
you should also keep in mind the functional flow block that you had
created for your design
this is the method have intended use been going about using your design
based on the selections that we have if we choose the menu option
they might actually improves the maintenance and reliability because
there isn't an electrical power system to check
you should remember your design attributes
so when you're looking at the cuts cross requirement what are the
attributes have cutting grass house we built that into our Design
for example if the customer requirement for cuts crosses been
interpreted as effective cutting mechanism fast spinning
which needs an adjustable speed we need to be able to show that that happens
with you know sign
in order to give it a good response in our weighted criteria
for purposes of determining which
requirements are more important than the others I go back to the pairwise
analysis that we did
he we found that cuts grass was the most important and spare parts is the least
important
along with cheap for the purposes of the evaluation metrics
I'm just gonna look at the top 5 customer requirements so that's
construct
our valuation metrics he way using the weighted criteria it's another these 0
comments a crossed as mandatory
according to the rank in my pairwise they get a number
in order from one to five this is translated into a waiting
where the most important gets the highest rating but the sky other way
using
provides a 5-3 exceeds 3-for-4
one for partial and there for non-compliance for the durable customer
requirement
I've given the petrol Mon on a relative compliance have three
which is full compliance this the same for electric
and manual you should be ready get the level to which your design
meets the requirements through your testing process
when we look at the cuts cross requirement the petrol-electric exceed
the compliance
where's the manual animates the compliance is because sometimes you have
to go back
and cut the grass again if we complete this for the whole matrix
if we complete this for all of the requirements be stuck to see which
design will be a perfect option
as low noise was a key requirement the petrol Omar doesn't score very well
in fact it's a non-compliant where's the electric is quite reasonable
and the menu exceed that compliance remember
but I'm providing a marquee I'm using my benchmarks
so would have come back and have a look at what my benchmark noise level was
and compared it against the attributes and then use the attributes to help test
that benchmark once you've completed the matrix
you can total the weighted value columns and you end up with the preferred option
he largely because it low-noise requirement the petrol lawnmower
doesn't result in the preferred option the electric and manual a very close
and would therefore warrant further consideration with more customer
requirements
for example a manual on most going to be very difficult
if the loan donate tomorrow is quite large
it might be worthwhile coming back to the customer and asking how much more
needs to be made
if I were to approach this is slightly different way the cuts cross customer
requirement
might need to be mandatory and I'm what set the benchmark at
a $5 for relative compliance if this were the case
than I could eliminate the menu option immediately because it doesn't meet
the cuts cross requirement to a high-level likewise with the low noise
option
if I was using the elimination method the petrol lawnmower would be discarded
in the second round a word of caution
don't just blindly choose the highest option this quantitative analysis
doesn't necessarily mean that you've captured
the system properly you need to interpret the results and news that
either improve your design or to improve the way that you communicate your design
when you assign a relative compliance you should be sure that the product
meets the test benchmarks for that design attribute
for fast meet that criteria and the customer requirement is very important
then you might need to eliminate that design and finally you need to make sure
that your customer requirements a complete
your valuation is using your model of the system
which might not be exactly what the customer wants so use this process is a
way of communicating your design
and then talking to the customer a recap of the key ideas from
the system evaluation on my classroom evaluation formally assists the design
selection stage
doesn't select the design for you it's a way of showing
the process in which he came to your best design you could complete the
evaluation
at multiple levels you could complete it at tertiary attribute level
a second reaction level a customer requirement level
a full system level or just a subsystem level
a full and complete evaluation would consider as many of these
ideas as possible and finally you should use the evaluation process to improve
your desired
not to validate how good it is because if you change something the customer
requirements if the market changed
if their requirements changed your desire might not be the best alternative
thanks for watching the online classroom series for engineering triple 25
make sure to check out the self-test some 10 and have a look at the call
waiting for the topic
we'll see you in the online classroom for triple 26 which would be looking at
the analysis if your design
greater detail see you then