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Establishing Product Functions

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Establishing Product Functions

So, in the last few classes we discussed about how do you identify the product specifications or basically how do you convert the customer needs into objective values or specifications, that is what, that is what we discussed and then we saw how do we actually put together all the information, what you get from the customer requirements,
from the benchmarking and then looking at the benchmarking values, how do you
identify the conflicts in the design as well as how do you get the target values for the
products.So, that is what we saw in the last few classes and we saw how to develop a House of
Quality based on the requirement, customer needs and metrics and the values. So, all of
you are comfortable with the House of Quality now? You have done it for the lab also.
So, today also you will be doing one House of Quality for another product so we will be
thorough with the House of Quality and how you develop the house of quality.
So, now once you identify the product requirements and the specification, the next
question is how do you satisfy those requirements? So, what you need to provide in the
product in order to satisfy the customer is the next stage where we look at the product
functions, how do you provide the functions in the product? That is the next step in
developing a new concept for a product.For example, establishing a product function is one of the important aspects so, you have
many requirements when it comes from the customer, for example, the customer says,
you want this product to be low cost and somebody says it is comfortable, it should be
comfortable to use. So, these are 2 customer requirements and we know how to fix the
metric for this and we can find the value also.Now, somebody says low cost and then we say that the metric is the cost of the product
should be less than or equal to say 1000, so this is what we specify in the product design
specification or product specifications but for comfortable we identify some metrics and
then say that the vibration should be less or it should, you should not feel the discomfort,
you should not feel any jerk, these are the things which you will say that the vibration
level or some other metrics we identify.So, if you, when you start designing the product you cannot really say that, how can I
satisfy the cost constraint, cost? So, cost can be satisfied by saying that it is a constraint
in the design, I mean you cannot go more than this value, that means only you can say,
but for comfort we can say how to provide comfort in the products. So, we can provide
something called function in the products in order to satisfy the customer requirements
but in the place of a cost you cannot say something like a function in the product which
will reduce the cost.So, this is known as the constraint in the design, so some of the things in the customer
requirements, some of the customer requirements can be satisfied only as a constraint in
the design. We will say that, ‘this cannot be more than, this is a constraint.’ So, whatever
you do in the product make sure that the cost is less than 100, there is nothing much to do
with the function of the product itself because any particular function is not going to
affect the cost or control the cost.So, any customer requirement in the product can be achieved either by providing a
function in the products or saying that this is a constraint in the development of the
products. So, are those customer requirement whatever you saw, we classify them into
two categories, some of the we say, they are the constraints in the design as a designer I
had nothing else to do with that, as a designer I cannot control it by providing a function
in a product to reduce the cost or increase the cost.
But comfort I can say that by providing a particular function in a product, in the product I
will be able to improve the comfort. So, this is the importance of functions in a product
because we provide a function in a product to satisfy the customer requirement, customer
has got specific requirement, easy to use or nice to have or easy to carry, these are all the
functional requirements which we can provide in the product.
So, any customer requirement can be addressed either using a product function or using a
constraint. So, we will not worry about the constraint work for the time being, we will see
how we can provide functions in the product in order to satisfy the customers
requirement.So, this is what we are going to look at, we identified many customer requirements and
identified the metrics, we will see how we actually provide that in the product to satisfy
the customer, that is going to be the discussion we are having.
Now, see that reducing the vibration is when you can provide a function in the products
so that that can be addressed by a function, it can be either adding a part or doing
something else, that may affect the cost of the product. So, we are saying that ‘I can
address that requirement of the customer by providing a function in it that works, but
somebody says that the it should be low cost, so low cost I cannot have a function in the
product to make the, reduce the low cost low cost low or high, it is not a products
function it is more of a constraint you put in the product saying that whatever you do the
cost would be this much.So, it is not a function of the product per say, it is more on the, as a designer I do not
have, I cannot provide a function in the product to control the cost, overall cost can
actually be restricted to this and I can work out on that point but I cannot provide a
function in a product to reduce the cost, that is what we are trying to explain. That is why,
when you, that function if it is increasing the cost it should identify another function
which reduced the cost, cost can be reduced, they are not independent. But what I am
saying is that this function we are adding or deducting is not controlling the cost.
If the function you are adding is to control the vibration, that is the focus of adding the
function, you are not adding a function to control cost. So, cost cannot be controlled by
adding a function or it is not a functional requirement but more of a design constraint
from the customer’s point of view. So, that is, so what we will do is identify a few
methods by which vibration can be reduced, suppose I identify 4 methods to do, when I
look at these four methods and then see which one is most feasible, where actually my
cost is not going to be raised.So, I will take that one on so, my requirement is not, primary requirement of providing
the function is not to control the cost but when I use a function and identify a method to
do that function I keep this in mind saying that ‘I have a constraint of cost so, when I
choose a particular function, I need to make sure that it is not adding to the cost.’ So, that
comes as a constraint from the design point of view.
Cost actually, cost all the things will affect the cost, I mean if I add additional function it
will raise the cost but then I need to make that requirement also, I mean so, if somebody
says the vibration to be reduced, I cannot say that because the cost is increasing I do not
want to reduce vibration. So, then I need to have a compromise on it, what is the best way
to address both the requirements.So, we actually discussed during the lab also, I used to ask you ‘what is the function of
these, what is the function of these?’ So, function can actually be defined as a statement
of relationship between the input and the output of a product that is the overall definition
of a function. So, if I ask you what is the function of a fan? What will be the function of
the fan? What is the function of the fan? Reduce temperature?
No, it is not going to reduce temperature, what is it going to do? It circulates air, basically
the primary function of the fan is to circulate air, so like that you see take any product
you will be able to identify a function, the top level function of the products. So, that is
defined as a relationship between the input and output of the product, you provide
electricity, you get air circulation. So, the relationship in between is known as the
function of a product.So, that is what is given here, a function of a product is a statement of clear reproducible
relationship between the available input and the desired output of the product. So, any
product we will be able to find an overall function like this. So, now what we are trying
to do is, from the customers' needs list in the House of Quality, we try to do a functional
decomposition of the product to identify what are the things needed in the product to
provide that function.For example, if you take the fan, the fan is to provide air circulation, how does it provide
air circulation? It needs multiple sub functions, first of all you need to convert the
electricity to mechanical energy then, you need to rotate the blades and you have to rotate
the blades you have to hold the blade and you have to keep your distance so all those
things actually lead to the final function.So, an analysis of a function into its sub elements which basically we call it as the
functional decomposition of a product. So, the overall function of the product needs to be
decomposed to identify what are the small, small things needed in the product, so that it
requires the final output. So, that is basically known as the functional decomposition.
And when we have these small, small elements then we can understand or we can
identify what way we can generate the concept to provide that function then, you get new
products, for example, you have a fan here, the fan is having a particular structure, a
particular function and specification. Now, I want to redesign and I want to make a new
fan, so I need to know how the fan is actually providing air circulation.
I looked at each one every function inside the product and then see can I modify the way
the blades are attached to it or can I change the way the blades positioned in a particular,
oriented in a particular way so, which one if I change in a different way I can get a better
product and it is basically I develop new concept to developing a new product.
So, in order to develop new concepts, I need to know what is happening inside the
products and we will be doing this function decomposition to understand what is
happening in a product, so that we will be able to redesign the product in a better way.
So, that is what we are going to do in the next few classes. So, this one I already told you
the customer needs can be met with the function or it can be considered as constraint as a
product development.So, for example, you take this product, how many of you have done these products? Most
of you have done this product. So, what is this product? This is a blender, right not a
blunder there is any difference? No difference, blender and a blunder no difference, so
what is the function of this? Overall function of this is to blend materials, you can blend
solid and liquid or both solid and liquid.Now, if you look at this product, finally you have provided electricity you provide
electricity outside and then you get that blending at the outside and this is what actually
happened so, it provides blending. Now, if you look at this you will see if I open out this
you will do something like this, so what is the function of this particular part, is there any
particular function for this?So, basically you have a rotation here, that rotation needs to be transmitted to the blade
so, the blade, the transmission is then through this but then you could have connected the
blade here itself, why not connect the blade here itself? Because we need an access point,
holding point and distance from here to here so that you can put it into a jar, so if you
look at this way, you can see each and every element in this product has got some
function.So, if you take this shaft this is a shaft, there is a shaft inside, this is a shaft if I hold you
can see so, if I take this individually what is the function of the shaft? First is transmitting
the torque, any other function you can see? So, it provides you access to the narrow jar
then, anything very obvious from this, what is another function of this shaft, who is
holding the blade? The shaft has multiple functions, transmits the torque, provides you an
elongation for which you can put a narrow jar and it holds the blade also, then what is
this part doing?It converts electricity to torque or mechanical energy and then that energy is converted
and transmitted to the blade, so any parts if you look at in a product, it has got some
functions. Now suppose, this blade is not held by the shaft, how will you hold it? Is there
another way you can do this? Can you think of any other way to do this? So, this is not
actually the new design that comes into picture, so we try to understand how the whole
thing happens and go through each and every stage and see if there is a way I can
redesign this so that the blade can be removed.Now, this blade cannot be removed, it is actually fixed to this so it is not a replaceable
one, now there is a requirement that the customer says that this blade often becomes blunt
so it cannot be used then, you have to throw this. Now, the requirement is that you need
to have some kind of a method by which either it should not become blunt or when it will
become blunt, we have to replace it.So, to do that we need to have a design where the blade can be in a different way or
different arrangement, that is why we need to look at the internal construction and how it
is actually providing the overall function then, you can develop a new concept to hold the
blades then, it becomes in new product and understanding that which one to be more,
which one will change is the job of a designer and therefore you need to understand what
is happening inside the product and to do that we do something, we do something called
as a functional decomposition of a products so, that is what we call this the functional
decomposition.We composed the product in terms of its functions so, what do you do in the lab is you
decompose or you do the product, you make it into parts but more from the physical
construction point of view, from the, where the product is assembled but here we look at
from the functional point of view and then try to decompose the product into multiple
functions and then check which function can be improved to get that desired customer
requirements because customer requirement be achieved through functions.
So, we decompose the product into multiple functions and then see which can be
modified so that is basically known as the functional decomposition, for example, take
this, what is this one? It is a car seat; it is a simple car seat. Now, somebody is designing
a car and then there was a customer requirement saying that there should be more
comfort for the driver, so driver comfort was a customer requirement.
And we all know that driver comfort comes from the seat, that is where he seats and then
by changing the seat or adjusting the seat or modifying the seat, there is a way to improve
the driver comfort so, to see that which, what to be change in the seat or what actually
happens in the seat, we need to find out what is the seat doing in the car or what are the
functions that provides comfort to the car, comfort to the driver.
So, we look into the seat and then see what are the major sub functions in the product,
that seat and then see which could be modified so that you can improve the comfort and
to do that we try to decompose these functions into many sub functions. Now, you look at
the car, you can actually see there are many things and can you tell me what are the main
functions of the car seats?Main function is to provide support to the driver, right and in addition to that what other
things it is doing or comfortable seat if the driver is in the seat? What are the functions
you can identify there? Everybody is saying but I am not able to hear, motion, adjustable
seat, what is that you have to adjust the seat, seat adjustment is one requirement, then I
have to reduce the vibration, so you have to control the seat vibration, what else?
Head support, Angle adjustment, backrest adjustment, backrest adjustment you have, and
that is basically the ergonomics, they call these ergonomic, seat adjustment, height also,
sometimes you can adjust the heights, what else? Seat belts, yes what else? Seatbelt,
seatbelt so now you know that a seat is not just for seating, it actually provides you
multiple things, so these are the multiple functions it actually provides in order to give
comfort.Now, if you are thinking of improving the comfort, you can actually look at any of these
functions and then see which function can be improved to increase the comfort, you can
come up with a new way to do the head support or a new way to the backrest or it can be
anything so, you go through the whole product and then try to decompose into sub
functions and then see which function can be modified or added so, that you will get
improved the performance.This is the way how you try to satisfy the customer requirement by looking at the
product. So, you can see there are multiple adjust positions, support lower body, dampen
vibration, transmit force, so, like this, you will be able to see multiple functions.
So, any products you should take, if I take this product, I can actually decompose into
multiple sub functions, so that I know which function to be modified to get a better
performance, that is the whole idea of decomposition. Any product you take will be able
to see this as an outcome.So, for example, you might have seen this product or you take the fan or you take that
drilling machine, you will be able to decompose this, how to do this in a systematic way
is the question, how can we have a systematic way of decomposing the product? We will
see some standard methods by which we can decompose the products.So, functional decomposition is the systematic process of transforming customer needs to
a clear specification of the functional requirement of the products. So, what are the
functional requirements needed in order to satisfy the customer is basically the functional
decomposition, for an existing product we can do this but for a new product we can
identify all the functions that are needed in order to get the customer requirements, so,
this is what we are going to see.Let me skip this, that is not an important one so, to do this we actually go by different
methods so, there are 2 simple methods which we call it as making function trees and
then we have another one called function structure so, first method, first we will look at
the SOP which is known as Subtract and Operate procedure, SOP is subtract and operate
procedure so, this is to identify all the functions needed in a products, for existing
products we can actually use SOP and identify all the functions in the products.
Suppose, you have a table fan which you are seeing in the lab now, substrate and operate
procedure says that you remove one part of the products, you remove one part of the
products and then try to operate it and then see if it is functioning, what is missing in that
product, when this product is not, this part is not there what will be missing in the
products or in the performance of the product, what is missing and that missing element
is the function of the products.For example, if I remove this shaft from here suppose I remove this shaft from here and
then try to operate this, what will happen? You do not get the blades rotating so, the
rotation of the blades and transmission of torque you do not get then, you know what is
the role of this shaft, like this if I remove this cable and then try to operate it, what will
happen? It would not operate because it cannot provide electricity.So, this way you can operate a product by removing the parts and then or logically try to
understand what is the, what is missing in the products by using that you will be able to
get all the functions that are known as subtract and to operate procedure to get the
functional decomposition. Start by isolating the smallest isolatable functions of features
and then prepare a function tree. So, what is a function tree?A function tree is you write the top level function of the products like in your assembly
charge you write the top level assembly so, here write the top function and then see what
are the sub functions providing this top function and then try to decompose each one into
small functions and if there is further you divide this so, this is known as the function
tree.So, by subtracting and operating you will identify, you will be able to identify the
smallest functions and those smallest functions will add up here and you will be getting it
as a function tree. So, this is known as the subtract and operate procedure for identifying
sub functions. So, now whenever you take out the product from the part from the product
in the lab, you should be able to see what the product is, this part doing so, in the chart
what you used to prepare in the lab you used to prepare a chart of the part, the part name.
Now, in the next one you need to add a column for that, what is the function of that part,
each part when you take out whether it is a screw or it is a shaft or it is a blade you see
what is it actually doing in the product and write down that as a function and when you
writing a function you need to keep in mind that the function should be written as a noun
and a verb, for example, transmit torque so, transmit torque is a function, hold blade so,
hold blade is noun and a verb so, like this you should be able to write the functions here,
whatever may be the function try to write it with a simple noun and a simple verb then
you are getting the functions identified in the products.That is what you will be doing in today's lab class. When you do the product tear down
you note down the part and its function also along with the other things like material and
everything that you write. Add this also, that is the one thing which you need to do. So,
let us look at how you actually find out the SOP.So, we will then do a simple example for a can opener, all of you hope, all of you know
about this can opener, all of you seen this and actually you are, this Milkmaid and all if
you want to cut open the can you will be using this and then you will be rotating it so that
it will actually cut the top cover of the can that is known as the can opener. Nowadays it
is all pulled out, so old one there was no pull out so you have to cut it open so that is the
one which we are shown here.If you have not seen I will show you later, but just to give an example, how do you
operate this, do SOP for a can opener so, each one you try to understand suppose, you
remove these parts and then see whether you can operate it or if you remove this part
whether you can operate it or you remove this blade, cutting blade whether you can
operate it so, this wheel. So, like this we try to see what each one is doing and then write
down it in the chart and that is known as the operate, subtract and operate procedure.So, we will take each one, handle one and then try to find out what its function, handle
two, support, blade, crank, wheel, shaft etc. So, this is the subtract and operate procedure
and finally you will see these kinds of functions. So, you can see it is like an import
force, transmit force, magnify force, convert force to rotation, guide rotation, stop
rotation, everything you can see is a noun and a verb. So, whenever you write the
function you have to use a noun and a verb. Stabilized can, transmit rotation, allow
rotation.So, this way you should be able to identify the function in each product, each parts by
writing it as a noun and a verb, that is the subtract and operate procedure which is
applicable only to existing products but it is not existing normally you cannot do this and
therefore we do something called a better method called FAST methods.So, the FAST method stands for Function Analysis System Technique. How do you
analyze the function of a product and that technique is known as Function Analysis
System Technique? So, it is used to define and analyze product functions and how the
products relate to one another. So, it is a very simple process, so we do this in a very
systematic and simple way by looking at the product and then trying to understand how it
works.So, I will give you a brief idea how it works, so we will see what are FAST methods
known as Function Analysis System Technique, not very fast it is slow. So, what we do
is, we actually draw two lines and say that this is what actually happens in the product,
you give an input to the product and you get the output of the product. So, this is the
function analysis system technique so, we draw two lines and say that this is what you are
giving as an inputs and input is an assumed function which say for example, you give
electricity, electrical energy here and then you get air circulation, air circulation here so
that is the output, this is the inputs and this is the output.So, what is happening inside is known as the product function so, all this what is
happening between these two lines we call it as the function of the products. Now, we
want to know what is happening to this electricity and how this electricity is converted to
air circulation at the other end and whatever happens inside is because of the products
and the product is doing something inside to get these converted, all this things needed in
order to convert this electrical energy to air circulation is the function of the product.
So, what we do here to understand the function is to assume that this air circulation is the
output and then I will ask the question how air circulation is happening, simply ask a
question how are you getting air circulation, how are you getting air circulation in this
fan? Simple looking at the products can you say how the air circulation is happening?
Blades are rotating, right so simply by rotating the blade you are getting air circulation.
So, basically how, you rotate the blade? The next question is how to rotate the blade?
You convert you convert electricity or you provide torque, you can rotate by providing
torque to the blade and how do you provide torque? You convert electrical energy, right.
How do you convert electrical energy? Using a motor right. So, now we have an answer
for the product so we do not need to go further ask the question then, we say you provide
electricity.So, that is the input so, now we have come to a path where we can say what is happening,
how we are getting air circulation by rotating blade, how we are rotating blade, you
provide toque, how are you providing torque, you convert electricity in to torque and how
do you do this by providing electricity, electrical energy.So, now we know what is happening inside the fan so this is the method by which we try
to identify the main functions of a product or the main line function or the critical path
function, so this one we call it as the critical path function. So, this is the first step now,
you can actually do it from the other side also, we can ask the question from here, why,
why you provide electricity? Because you want to convert the electrical energy, why do
you want to convert the electrical energy?Because you want to create torque, why do you want to create torque? Because you want
to rotate the blades, why do you want to rotate the blades? Because we want air
circulation, this method of identifying the functions using asking questions how and why
is known as the FAST method of functional decomposition. That is the FunctionalAnalysis and System Technique.
Now, this is only the critical path, we need to have many other functions for this because
if you want to rotate the blades, what are the things you need to rotate the blades? Blade
should be there then, someone should hold the blade, so who will hold the blade? So,
holding the blade is a function. Now, just holding the blade is not enough, so in order to
hold the blade you need to do something, you need to change the blade, so, you may have
to accept the blades and then if you have to change the blades you may have to release
the blade and the blade should be locked.So, there will be many functions coming there, also when you see that it has to connect
electrical energy there will be many functions associated with that, you have to accept
electricity, you need to regulate electricity. Similarly, when you provide torque you need
to convert electrical energy to torque, there will be many other sub functions like there
may be some vibrations or there may be some noise so you need to overcome those
things.So, there will be many unwanted functions associated with the sub functions so, whatever
maybe the critical path function, along the critical path function you will be able to
identify some required functions and sometimes these required functions will lead to
some unwanted functions also, so these unwanted functions need to be compensated by
adding an additional function.For example, if there is something like an unwanted function of generating heat, when
you convert electricity you will see that there is a need to reduce the heat, so you cool the
system. It will be a required function then. Similarly, if for every system there will be
some all-time functions, anytime this function should be available in the product for
example, safety of the, electrical safety is an all-time function so, this should be always
there the product is, as long as the product is in use we need to have this safety.
Similarly, there will be some design objective, so that when we write it as another
function and design objectives may be to reduce noise, maybe a design objective. So, this
is the way how you actually develop the