Good morning! Welcome back to the functional and conceptual design. In the last class we
discussed or briefly mentioned conceptual design, how we can develop new concepts or what
is the importance of developing concepts to solve the design problem. So, you may be having
a product development task and while developing the task you will go through the various
stages and identify specific functions which you want to improve.
Now, the question is how do we actually develop this, how do we actually develop concepts
for addressing this function and improve the product. So, that is all about the conceptual
design. So, we will look at the methods by which we can develop concepts and what are the
standard methods available for developing concepts as well as choosing concepts.
So, last class, we mentioned that the product concept is an approximate description of the
technology working principles and form of the product. So, at the end of this exercise you
need to have an approximate description of the technology, the working principles, as well as
the form of the product, which is what we expect at the end of the conceptual design exercise.
And it is a concise description of how the product will satisfy the customer needs.
So, you have some specific needs identified and based on the needs you identify the specific
functions. Now, the question is how this concept is going to address those customer needs.
The quality of underlying concept greatly influences the success of the product. So how good
is your concept, how creative and innovative is your concept determines how successful your
product will be? So, this is what that we are going to discuss in the next few sessions.
And we have something called an empirical design process, where we try to design by
analogy. That is known as the empirical design process which we normally follow in the
conventional design process. So, here we compare what you want to design with what has
already been designed. So, this is one of the basic methods or basic strategies adopted by the
designers in order to get the design done. So, this is known as an empirical design process.
So, where we just look at the existing products and then see if something can be improved or
modified to solve our problem. So, that is the empirical design process.
So, look at what has already been designed and then see what is to be done in order to get a
particular function or a particular need satisfied. So, here an empirical study of products is
conducted to gather the initial design knowledge base. So, any designer needs to have a good
knowledge base to start with the design process.
If you do not have much of a knowledge base, you will not be knowing how to develop new
concepts or you will be very limited in developing concepts. That is why we need to have a
good design knowledge base and that will actually come from the existing design. So, you
need to study the products, existing products and then try to understand how people have
been trying to solve problems and then come out with products or concepts to solve the
This information or this knowledge is very essential for any product designer and this can
actually be obtained by studying the existing products. By recording existing design
knowledge, it can be reused to help designers choose a high quality design in the simplest
form, instead of choosing a poor design and pushing it until it works, often increasing the
complexity of the product.
If you have seen very good designs and you have seen many products which are designed by
expert designers or high quality designers, then you know how they are actually solving the
problems and what kind of concept they employ in order to solve particular problems. And if
you have this knowledge base, then it will be easy for you to get into good designs. And
many times you will be able to reuse in some different form, not exactly the same thing you
are copying but you will be able to reuse those concepts and then come up with quality
designs for your product.
And if you do not have that kind of a database or knowledge base, you will be starting with
some basic design which is very poor. And it does not meet many of the basic requirements.
Since you do not know the existing design you will start with a very poor design and then
keep on working on it. And probably at the end of, may be at the end of the process you may
be getting a design. But you will be spending too much of time and sometimes the
complexity of the product also increases.
To avoid all these things, you need to develop a good knowledge base before you start the
conceptual design stage. Any designer needs to have a very good database or very good
knowledge base about the existing designs, you should go through the products, existing
products similar or different from the existing problem or the current problem. And then this
knowledge base should be generated and then see how to use this knowledge base to come up
with better designs.
So, that is the requirement in the empirical design process. So, how is it done? We will
actually do a lot of experiments with the existing products and then generate the knowledge
base. And the premise in this case is that the quality designs come from experienced
designers. And it is a fact that an experienced designer will be able to come up with a good
quality design. The more the experience the more will be the quality of the product, the
concept will be better and that is the basic philosophy of the empirical design process.
So, you look at the existing process design and try to develop the knowledge base to help you
to come up with better designs. It is not to copy the existing concepts, but basically to
understand what is existing and how, what is the current level of knowledge, data, and
technology and all in a particular field. And then see how you can actually utilize that
information or that knowledge to come up with better designs.
This is what actually you are doing during the lab exercises also. We are actually asking you
to open a product and then try to identify the components and map the components to the
functions and then to get a particular function what concept is used by the designer. So, by
going through multiple products, you will know that for the same function you can have
multiple concepts and then you can have an understanding of what are the different concepts
that can be used to achieve a function.
So, that is one of the reasons why we have a lab session or we are having multiple lab
sessions as part of this course. So, what we do, this is the concept capturing stage. If you want
to capture the concepts from the product, you need to open up the products and then try to
understand. Then you derive each product's functional model. So, once you have a product,
you can actually derive a functional model of that product. And then you document the
product components by opening up the product.
So, when you get a product, you open up the product and then identify different components
within the product. And since you have a functional model already developed for that
product, you will be able to map the components to function. Any component you take, there
is a shaft or there is a gear or a belt drive whatever it is, it is actually a product. But when you
look at the functional decomposition then you will see that, there is a mapping, okay this
particular function is satisfied by this particular component.
So, that is a concept, when you have a component that basically says that the function has
been converted into a physical form and that is the concept employed for converting that
physical form you will be able to identify. So, that is the reason why we need to have this
mapping of components to function. As the products are taken apart, each part is mapped to
its related sub function from the functional model.
For the empirical study to be effective, the function of every part must be determined. So, the
function of every part need to be identified to complete the study. And if a component
function has been overlooked in step one, then the functional model is updated. Now, this
functional model was developed based on your own understanding of the functional structure
or the functional decomposition.
Now, you will see, go through these functional decomposition and then look at the product
components and identify the functions of these components and then look at your function
decomposition, is this function identified in the functional decomposition or not. That is
basically the updating of functional decomposition, you update the functional decomposition
based on the components you identify in the products.
And record the function component matrix. So, finally, you will record the mapping of these
functions and components in a matrix form so that you will get a clear idea what kind of
concepts are used. Based on this you can identify the useful concepts employed in the
product. Like this if you do for multiple products, you will be getting a large database and
this database will be highly useful when you have to solve your own problem.
Because once you have an experience of seeing something, you are not really designing the
product, but you are actually looking at that product, existing product and trying to
understand how a designer has come up with the concepts to solve the different functions
needed in the product. So, that is the empirical design process where you try to learn things
from the existing products and then use this knowledge to develop new concepts for the
So, every designer has to go through this, unless you do this exercise, you cannot be a good
designer, because good designs come from experience or good designs come from
And finally, you need to go for the concept generation for your problem. So, you develop a
database and then use that database as a starting point and then start generating concepts for
the problem that for the current design problem you have identified. So, you may be studying
the design of a product, for example, you take that you want to develop a new washing
machine, which can actually reduce the water consumption, that is the requirement. The
design objective is to reduce the water consumption.
Now, you will start the process. So, you look at what are the functions needed in the product.
You need to do a functional decomposition of course, you have the customer needs identified
and based on all those customer needs, one of the top most need is reduce water consumption
and then you try to get these functions. And we need to convert this into the form made
through architecture and layout of the product.
So, you develop the functional decomposition, then identify the modules needed in the
product in order to satisfy different functions and develop an architecture and a layout. So,
that is the stage where you have the product layout. Now, for each module, you identified
modules, there is one module which actually takes water and then passes water through
different elements and then finally, it mixes with soap and then uses it for rinsing the clothes
and then comes out as dirty water.
Now, that is the module that you identified, a water handling module. You need to look at the
functions needed in the water handling module and then see which function can be improved
to reduce the water consumption. So, that is the particular function you identify. Now, you
need to develop a concept to address that particular function. So, in a product you may be
addressing one or more functions, but you will not be doing the total product as a complete
That will be applicable only when there are no such products and it is a completely new one
and there is no concept which can be employed for the existing one, then only we will go for
the complete development of the complete concept, all the concepts for the other function.
But in most of the cases you will be doing concept development for a few functions which
you identified are critical. And then generate concepts to help alternative design ideas to
satisfy the product functions.
So, I take one or two functions or a few functions and then generate concepts to have
alternative design ideas. So, we start with the design ideas and then move to concept. So,
ideas and concepts are slightly different, they are not one and the same, I will tell you the
difference. So, you develop a lot of ideas, and then a concept needs to be worked out from the
ideas which you find as the most feasible idea. You should develop as many ideas as
possible, that is the requirement.
You need to have a large number of ideas to solve a problem. Suppose, there is a problem of
reduction of water, you cannot just have one idea, you need to have a large number of ideas
and then you need to choose the best idea and then develop the best concept from that, that is
the requirement in concept generation. So, in order to have this stage you need to have the
So, we will, as a designer you learn a lot of, you go through a lot of products and then
generate a lot of idea, I mean, capture a lot of ideas from those products. And with this
background, you will start attempting to solve this problem. So, that is the concept generation
stage where we tried to come up with ideas first. A large number of ideas to be generated to
solve the problem.
So, that is the idea generation stage and then this idea, so, idea will be more of an abstract
form of solving the problem. For example, I want to fly is an idea, but how can I fly, so what
is the technology I can use, what will be the form of this and what kind of issues are there
identifying all those things are basically a concept. So, I can fly is an idea, but if I say that I
can have two wings and then I can flap the wings at a particular frequency, and then I can
overcome the drag forces or these forces will be overcome by the flapping of the wings.
And so, giving a more detailed description of what the idea is and how it is going to function
and that is known as that concept. So, ideas are a more abstract form of a way to solve, but
concept is a clear definition of, a description of how this can actually be implemented. So,
that is the difference between an idea and a concept. So, moving from idea to concept is a big
exercise, but the first thing is to have an idea first of all. So, you need to have ideas to get the
So, you start developing large number of ideas, and then many ideas will be not feasible. But
look at all those ideas and then see which other ideas which seems to be possible, and then
start converting that into concepts. And then you will be getting lots, again, you will be
having, it is not one concept, you would need to have many concepts so that you can, even if
one fails, you would be able to go with another concept to solve the problem. So, that is the
way how we will be going in the concept generation exercise.
Just to explain the empirical design process, which I already mentioned, so we will just take
an example and then go through the stages and then see where we reach, how we reach the
concept development stage. So as I mentioned, in the empirical design process you look at
the problem and then try to function decomposition and then see how to solve it. So, let us
take a very simple example of this, designing a better handheld nailer. And then see how the
concept development can be approached from the basic problem and then moving through the
problem at different stages, reaching the concept development stage.
So, you know that I mean this I had already explained in the previous class. If you are using
the conventional hammer for nailing, you have a lot of difficulties. If someone wants to make
it a handheld nailing nailer or electrically operated handheld nailer. This is the requirement.
Now, you want to solve this. Then we will have the basic assumptions in the mission
You go back to our initial classes where we talked about the mission statement and other
things. In the mission statement, we will talk about all those assumptions, basic requirements
or fundamental things that we saw, I mean, provided in the product. So all those things we
will identify, we will say that the nailer will use nails. So you are saying that, I want to
replace the nailer, I do not want to do this nailer, can have many solutions, I can actually say
that, no need to use nails, you can instead you can use adhesive or screws.
But that is not the problem that you are trying to solve, you are saying that the nailer will use
nails and then we need to join different components or different parts. And it will be
compatible with the nail magazines on existing tools. So you are saying that, there are
existing tools available in the market to solve this problem. So I will be using the same kind
of nail magazine, I mean, the set of nails that can be inserted into this product, and then I will
be developing the product.
The existing nail magazine should be compatible. The nailer will be compatible with the
existing nail magazines. And it will be used only for nailing into woods. So you are telling
that is only for wood not for other applications, metals or any other, we will not, we are not
considering. And it will be a handheld nailer. These are the things which actually come from
your technical questioning.
When you have a technical questioning in the beginning, you will identify many things and
then that will be put into a mission statement and this will be a part of the mission statement.
So, it is not exactly the full mission statement, but some of the assumptions in the mission
Now with these assumptions, we will go to the problem clarification. So what are the needs,
the target product specification, so we need to look at the needs and the product specification.
Again, going back to our old earlier slides, we talked about identifying the customer needs,
and then converting those subjective customer needs into objective specifications. Then, after
going through this, we will get the target specifications which will be coming through your
house of quality or QFT analysis and we will come up with the product specification.
We will say that nail length from 50 millimeter to 75 millimeters and maximum energy 80
Joules, nailing force, I mean, these are all the specifications that you can identify going
through the various stages in the design process. Basically in understanding the opportunity
we will do all these things and then we go for the developing the concept stage.
Once you have the specifications, you need to look at how we satisfy those customer needs.
Because you identified that you need to increase something, you need to provide this much
force. Now, how do we provide those forces, how do we ensure that the nails are moved at a
particular speed or force is applied at a particular point, all those things need to be provided
and to provide that we need to see what kind of functions are to be provided in the product.
We will do that through a simpler sub problem or saying that we can reduce the function
problem into subproblems, that is the decomposition. Now, the main function of the nailer is
decomposed into smaller functions. So, the design of, this is not an example for the nailer but
in general we are talking about. Suppose you have a design of a copier, that is the
photocopier then we can say, actually say that document handler, printing device, image
capture device. So, this is the way we can actually decompose the functions.
Same way in the case of a nailer we can identify how we actually provide the function of
handling, that is, it should be manually handled. So, manual handling is one problem. The
other one is moving the nails at a particular rate for nailing and then providing a force to the
nail head. So, these are the sub problems that we can identify in the nailer. So you decompose
the problem into subproblems through a functional decomposition. And there we can use the
function structure method to decompose it and identify the functions.
So, the decomposition may not be very useful for products with extremely simple functions.
So, when you have a very small problem or very simple problem that you are trying to solve,
then you do not need to go for the functional decomposition. But whenever there is a
complex operation, better to go for functional decomposition because you will be able to
solve the subproblems first and then move to the higher level problems.
So, a problem decomposition or sometimes we call it a functional decomposition also.
Though we are trying that, saying it as problem decomposition, we are saying that providing
a function is the problem now, and then we are trying to decompose into sub functions.
So, make it as a black box and then based on the material energy and flows, we will try to do
this and divide the black box into sub functions. You can actually have multiple steps in this
depending on the complexity of the problem you may have 3 or 4 steps or more steps in the
decomposition. So, that is functional decomposition.
For example, if you look at the nailer, you can see these are the input energy, material and
signal. So, the energy is electrical energy if electrically operated plus the manual energy will
be there. And then you have this material that is the nails going inside and then the signal is
further tripping or dispatching that or that kind of information that you are getting. So, you
have this input and output, now you look at what is happening to the input and how it is
coming out as output.
So, for example nails need to be stored in the machine. That is a magazine, the nail magazine
that you say it can be used for storing and then you need to isolate the nails. So, you have 10
nails or 20 nails stored, you need to take one by one. So, that is how to isolate the nail and
then how to apply translational energy to the nail. So, you isolate one nail and then apply a
translational energy to the nail, so that it can actually move forward.
So, that is the function needed for this in the case of nails. And similarly you have the energy
whether you store or accept. If it is a storage battery type you store, if it is not a battery
operated then you accept energy, then convert energy to translational energy and then apply
the translational energy. Here is when it is tripping or not, then if it is a tripping then you
have to trigger the tool accordingly. That is basically the information.
It is a very simplified decomposition as shown. Now, we know that store nails are a function.
But how to store nails? Now if you are going to use the current existing magazine, nail
magazine, then it is a question of how do we actually provide a space for holding it in this
magazine? So, that is the concept to be developed for that. Similarly isolate the nail, how we
actually take the nail one by one from the magazine, so that is another function to be
Suppose you are developing it, it is different from the existing one then you need to develop a
concept to do this. How can I take nails one by one from the nail magazine? So that is where
you need to develop a new functional concept to do that. Similarly, applying the energy,
So, depending on the way you isolate as well as the current methods of providing this kind of
energy, you can look at that and then see how you can come up with new concepts to come
up with a new concept to get this particular function. This way, you look at each function and
then see which function needs to be improved and how can we develop a completely new
concept for this. In some cases, you will be able to use the already existing concept.
For example, to store energy, you do not need to come up with a totally new concept, what
you need to provide is a battery. So, the battery is a concept for, already existing concept for
storing energy. So, what you need to do is to provide a battery and then provide a provision
for the battery to sit inside the machine. So, that much only you need to have it in this one.
So, you are not worried too much about developing a totally new concept for storing energy
because that is not the focus.
That is how we should look at the problem and then try to solve. For example, convert energy
to translational energy. So, converting mechanical electrical energy to translational energy is
the problem here and there are multiple existing concepts. So, if you feel that I can still use an
existing concept I am not interested in completing, developing a completely new concept for
this. You can actually adopt an existing method and then fit it into your design problem.
You may have to make some changes, you have to adapt that particular concept to suit you,
but you do not need to come up with completely new concepts to solve this problem. So, that
is how we need to start looking at the problem and identifying which function you want to
improve and then you develop the concept for that. So, this is the way we do it and then the
question is how we come up with a concept for this. So, isolate the nail or whatever the
function you identify, you can come up with the nail.
This functional decomposition which I had shown you, may not be unique. Again this we
already mentioned, that depending on the person and depending on your focus, you can have
a different decomposition. So, you can create several drafts and then work to define them into
a single diagram that the team is comfortable with. If it is a complex one, then there will be
multiple ways you can do the decomposition. So, you can decompose it in different ways and
then consolidate that in a single decomposition.
So, once you have done that, then the question, the next step three is to develop concepts for
sub function. So, I took that example to tell you where actually this fits in the, developing the
concept fits in the whole process of design problem solving. It is applicable to any design
problem whatever, maybe you are design problem, you have to go through those steps and
then identify the function or the sub function for which you want to develop a concept.
So, what I am going to discuss in the next one or two classes is the methods by which we can
actually develop concepts. Because concept development is again a creative design process.
But still we need to go in a systematic way so that you will be able to get a large number of
concepts, good quality concepts. So, how do we ensure a good quality concept at the end of
this process, that is ensured through a systematic concept development and selection process.
So, this is what we will be discussing.
And before we get into that, let me tell you what main issues you will face while developing
concepts. Because when somebody says okay I want to solve this problem, let us have some
ideas, we start making ideas or start developing concepts. But many times, all these fail
mainly because we have many pitfalls in the process that we follow. Or when we do not
follow a systematic process, you will most likely fail in coming up with a good concept
because a process which is not systematic, has got a lot of flaws. And that may lead to failure.
So, let us see what these pitfalls are. So, one is that the consideration of only one or two
alternatives often proposed by the most assertive members of the team. Suppose you are
designing this, I mean you are solving this problem as a team and then you start developing
the concepts, you will start with only very few concepts, you say that, very few alternatives.
You will say this can be done in this way and this can be done in this way.
And that will be proposed by the most assertive member or the team leader or whatever his
position is and that person says and many others will simply listen, they will say, let us try.
That is a very bad approach, you cannot have only very few ideas, you need to have a very
large number of alternatives to start with. And this has to come from everyone. It is not only
from the assertive member or a few members, everyone should be given a chance to come up
Whenever there is a need to develop concepts, make sure that you have a large number of
alternatives to start with. And another problem is the failure to consider the usefulness of
concepts employed by others in related and unrelated products. Many times because your
experience or your background information or knowledge is very limited, you may fail to
consider the usefulness of concepts already employed by people or in the products which are
related or unrelated to your problem.
For example, you are looking at the water conservation issue or reducing the usage of water,
then you will be looking only at the washing machines, how other washing machines are
using water and what kind of method they are using to reduce water. But there may be many
other situations where people try to reduce consumption of water, it may not be in washing
machine, it can be in a chemical industry, it can be in a paper industry, it can be in a food
industry or it can be in general household, how people try to reduce the use of water.
You need to look at all those alternatives employed by people, whether it is related to the
product or not related to the product, you should be able to look into those alternatives and
also. If you fail to consider that, then again you will be failing in getting a good solution. So,
that is the second point. The third one involves only a few. Suppose you have a 6 member
team, only one or two will be actively participating in coming up with alternatives.
So, the rest of the people will not be having any interest in these ideas that the others
proposed to me. And therefore, their commitment and confidence will be very low with
respect to that concept or that alternative. And this is why we need to have the participation
from everyone. And everyone's views should be tak
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