\chapter{Developing Concepts}

So far we have developed methods to understand and define customers' needs as 
clearly as possible. We have used objective trees to expand on the needs and determine the 
various levels of goals. Functional trees were then used to address the different functions 
that need to be carried out in an hierarchical manner, to satisfy the needs. Then we drew up the 
specification chart based on what we needed to achieve, and what we needed to do to 
achieve them. The specifications that must be satisfied were classified as "must", and those that will 
simply enhance the product quality as "desired". However, specifications described what needs to 
be achieved in a measurable quantity rather than describing a qualitative desire expressed at the 
objective stage. The next step is to come up with more than one artifact that will satisfy the  
needs of the customer, taking into consideration the desires and wishes of the 
specifications. These concepts represent muliple solutions to the problem.


The generation of concepts is the central aspect of the design process. The mysterious 
process of generating an entirely new product is considered creative. The logical steps that we 
adapt rationalize the design process and provide opportunities for creativity. Though creative design can produce a  revolutionary product, it is much more common that 
creativity is applied to the evolution of an exisiting product or system. Usually customers 
prefer the improved performance of a standardized product rather than a novelty. Making variations 
on established artifacts is therefore an important feature of design activity. This is the usual 
way in which creative thinking is put into use. In particular, creativity can often be 
seen as the rearrangement of exisiting components.

\section{Visual Thinking and Creativity}

Creativity is one of the most written about and controversial subjects. Since creativity is 
defined in a number of ways, there are many books that claim to suggest ways to improve 
it. To engineers, especially mechanical engineers, creativity means the act of solving a 
problem in a clever and novel manner. In design, this means seeing the product in an 
imaginative way, since the product can only be imagined. Visual thinking enhances the 
imagination, and written/oral thinking translates the imagination in a form that others can 
understand. Visual thinking pervades the entire spectrum of human society; for instance, 
mathematicians consider abstract space-time relationships, chemists construct new 
molecular models, pharmacists adapt a new catalyst in a drug, a professor concocts a new 
method of teaching through group learning, and a football coach dreams up a new offense 
strategy. Hence, visual thinking is not restricted to Picasso, Rembrant or Van Gogh. It is utilized by many people 
in the everyday activities of life.

Visual thinkers utilize seeing, imagining and drawing in an integrated and dynamic way to 
create solutions. With a visual understanding of a problem, well defined by the objective 
and functional structures and a corresponding specification, they imagine alternative 
solutions. Rather than committing the solutions to memory, they draw a few sketches 
which they later embody into a workable solution. Such solutions can then be compared 
to what they imagined as the goal, before modifications are iteratively made until the 
problem is solved. 

Creativity depends on the process of thinking, which in turn depends on the interaction 
of thinking with observing, imagining and drawing. When Sir Alexander Fleming  
observed that the contamination of his samples was caused by bacteria, he went on to 
discover penicillin. Needless to say, many others discarded the same 
contamination as a nuisance and did not imagine the use in a different sphere. Similarly, a child playing 
with legos is imagining a solution while seeing the construction pieces.

The inner imagery of the mind's eye has played a central role in the thought processes of 
many creative individuals. Albert Einstein ascribed his thinking ability to imagining abstract 
objects. Kekule discovered the all-important structure of the benzene ring in a dream. Most 
visual thinkers clarify and develop their thinking with sketches. Drawing not only helps them  
to bring vague inner images into focus, it also provides a record of the advancing thought 
stream. Sketches expand the ability to hold and compare more information than is possible 
from simple recall from the brain. Sketches are usually extensions of thought, and they provide a 
conference table to talk to oneself.

Researchers have varied opinions about whether or not creative thinking can be taught. Some 
reports show that direct training in thinking can produce the advancement of thinking 
skills in significant increments. A number of thinking strategies can be taught, for example, the thinker who 
fluently produces a number of possible solutions to a problem is usually more successful 
than a thinker who settles for a one solution. Our traditional educational system which 
emphasizes the 3R's, usually ends up reducing or destroying the ability to appreciate imagination and 
mental visualization. Seeing, dreaming and drawing are essential to visual thinking and 
hence, to creativity. Contrary to common belief, seeing is an active art and not a passive 
experience. The common complaint that a person can lack imagination is baseless, because one who 
dreams does imagine, and everyone dreams. The fact that kids draw more than adults indicates that
drawing is simply not encouraged among adults, and that drawing is not complex.


Visual thinking is not just thinking upon seeing. Seeing is more than sensing; seeing 
requires matching an incoming sensation with a visual memory. A knowledgeable observer 
sees more than a less knowledgeable companion since he or she has richer stock of 
memories with which to match incoming visual sensations. Recentering is seeing from a 
new perspective, abandoning familiar points of view, and fostering new ideas. In other 
words, making the familiar strange and strange familiar. One should develop the ability to 
break away from the "objective" reality, and move to a "subjective" level which will encourage the 
associative flexiblitity inherent in the creative art.


\section{Developing Working Structures}

Once the various functions at various levels are known, it is then important to find the 
principles working for each of the sub-functions. A working principle must be based on 
the physical affect needed to achieve the given function based on the flow of materials, 
energy and information within each function. Each function may be achieved in a number 
of ways. One important tool that can be effectively used is a design catalogue. Figure \ref{basic} 
shows the schematic of a design catalogue where each sub-function is shown in the left 
column and the many possible solution in the rows. Figure \ref{extract}  shows an extract from a 
classification scheme for an impulse-loading rig. The first four entries are the functional 
requirements of energy conversions (electrical to mechanical, electrical to hydraulic, 
mechanical to mechanical and mechanical to hydraulic), the fifth is to store energy, the 
next is to control energy and the last to vary the component of energy. In some cases, 
there are as many as eight possible ways to achieve the same function. The general idea is 
to identify as many possible means to achieve the same functional requirement.

\def \epsfsize#1#2{0.7#1}
\begin{figure}
\epsffile{../figures/7-1.eps}
\caption{Basic structure of a classification scheme with the sub-functions of an overall function and associated solutions}
\label{basic}
\end{figure}

\def \epsfsize#1#2{0.5#1}
\begin{figure}
\epsffile{../figures/7-2.eps}
\caption{Extract from a classification scheme for impulse-loading test rig}
label {extract}
\end{figure}


Another frequently occuring design situation involves using the same working principle, but 
changing the geometry or material combination (FORM) to enhance the functional 
requirement.

\section{Steps to Develop Concepts from Functions}
\begin{enumerate}
\item Step 1: Developing concepts for each function.

The goal of this first step is to generate as many concepts as possible for each of the 
functions identified in the decomposition. There are two activities here that are similar to 
each other. First, for each function, develop as many alternative functions as possible. 
Second, for each sub-function the goal is to develop as many means of accomplishing the 
function as  possible. In the earlier example, storing mechanical energy could be achieved 
using a flywheel, a translating mass or raising the mass, or as stored energy inside a cantilever. 
Or, the mechanical energy can be converted into electrical energy and stored in the battery 
or in the capacitor. If there is a function for which there is only one conceptual idea, this 
function should be reexamined.

If there is a very limited idea, it may be due to the fact that the designer has made a 
fundamental assumption without realizing it. For example, one function typically encountered 
in attaching is to move in closely. If moving by hand is the only 
way, then the implicit assumption is that the part will be assembled manually. This 
may not be a bad assumption, except that it may not have a universal validity.
… The function may be indicated as how and not what. If the funciton is to roll on the 
rail, then the general concept of move has been specifically indicated to the movement 
along the rail.
… The designers may have a limited idea of other fields.
It is generally important to keep the level of abstraction (details)at the same degree.

\item Step 2: For each function or functions, list the means or methods to be used. 

These secondary lists are the individual sub-solutions which, when one is combined from 
each list, form the overall design solution. These sub-solutions can also be expressed in 
rather general terms, but it is probably better if they can be identified as reak devices or 
subcomponents. For example, when you want to lift, you may like to use a ladder, screw, 
hydraulic piston or rack/pinion. The list of solutions should not only contain the known 
components but also any new or unconventional methods or solutions for achieving the specific task. 
Many brainstrorming or lateral thinking concepts can be employed in order to arrive at the 
solution. One should remember that many possibilities (at least three) are necessary for 
each function. Also when trying to identify artifacts for a given function, only that 
specific function or sub-function should be the criterion, not the overall function or 
whether the overall function is possible in that case. Those eliminations will be taken care of at a different 
time in the design process.

\item Step 3: Draw up the chart containing all the possible sub-solutions.  This chart is called the
morphological chart.

The morphological chart is constructed from the functional list. At first this is simply a 
grid of empty squares. The left hand column lists each function identified in the 
functional diagram. Across each row, it lists all means (methods)for achieving the function. 
On the left hand column, one each is entered in a square. As many methods as possible for 
each function should be entered. Once finished, the morphological chart contains the 
complete range of all different theoretically possible solution forms for the product. This 
complete range of solutions consists of the combinations made up by selecting one sub- 
solution at a time from each row. The total number of combinations is rather large. The 
list of  methods should be kept to about five to keep the total solutions within a 
reasonable range.

\item Step 5: Identify feasible combinations.

A list of concepts will be generated from the previous step for each function. The next 
step is to combine the individual concepts into complete conceptual designs. The method 
here is to select one concept for each function and combine those selected into a single 
design.  Some of these combinations, probably a small number, will be existing solutions; 
some new solutions; and some (usually a great number) impossible solutions. It is necessay 
to identify potential solutions for further consideration. One or more of those better 
solutions, for reasons of cost, performance or novelty will be explored for further 
development.

\end{enumerate}
\section{Sources of Concept Ideas: Techniques to Enhance Creativity}

Dreaming up new ideas is an enjoyable experience. If the idea is translated into an artifact 
that works as desired, the designer takes great pride in his or her creativity. It may turn 
out that the idea may not be entirely new; since there is never a unique way of finding out
whether a similar idea has ever been used.

Patents can serve as an excellent source of ideas. However, it is difficult to identify the 
specific patent that contains the idea that you are looking for. There are two main types 
of patents: utility patents and design patents. Utility patents deal with how the idea works for 
a specific function. Design patents only cover the look or form of the idea. Hence, utility 
patents are very useful since they cover how the device works, not how it looks. Since there 
are about five million utility patents, it is important to use some strategies in order to hone in on 
the one that you may be able to use. Use the class and subclass concept to identify the 
artifact of interest. Figure \ref{manclass}, shows the class/subclass structure for a bicycle and some 
components that go in the bicycle.

\def \epsfsize#1#2{0.7#1}
\begin{figure}
\epsffile{../figures/7-3.eps}
\caption{From Manual of classification under class 280}
label{manclass}
\end{figure}

The next obvious place to find information is in reference books and trade journals in the relevant area.

Another obvious information source is consulting experts. If designing in a new domain, we have two 
choices for gaining the knowledge sufficient for generating concepts. We either find someone 
with expertise in that time, or spend time gaining experience on our own. Experts are those 
who work long and hard in a domain, performing many calculations and experiments 
themselves to find out what works and what does not. If we cannot find one or afford one, 
then the next best source is the manufacturer's catalogue or  manufacturer's representative. 
One of the ways to identify who the manufacturers are is by using catalogues, such as the Thomas Register, or 
in current technology on-line searches.

Brainstorming is also a great source of ideas. Brainstorming, initially developed as a 
group-oriented technique, can also be used by the individual designers. What makes 
brainstorming especially beneficial for group efforts is that each member of the group 
contributes ideas from his or her viewpoint. The rules for brainstorming are rather simple:
\begin{enumerate}
\item Record all ideas. That is the role of the recorder.
\item Generate as many ideas as possible, then verbalize these ideas.
\item  Think wild. Silly, impossible ideas sometimes lead to useful ideas.
\item  Do not allow the evalution of ideas at this time. It is time for generation of them. This 
rule is very important. Ignore any evalution, judgement, or other comments on the 
value of an idea.
\end{enumerate}
It is very imporant to encourage humor and a relaxed atmosphere during brainstorming, 
only then can ideas flow freely.

\section{EXAMPLES}

\subsubsection{Example of a Potato Harvestor}

Consider the case involving a design need to improve a potato harvesting machine. The figure shows 
the morphological chart for the problem. It is presumed that objective tree, functional tree 
and specification have already been identified for the problem. In the functional 
decomposition (based mainly on the flow of material) lift, sift, separate leaves, separate 
stones, sort potatoes and collect have been identified as the sub-functions. Accordingly, 
the six functions are entered on the left hand column of the chart.  Each row represents a 
specific function. For example, row 2 is the function "sift", and we need to find means to 
achieve the function of sifting. The chart shows four different means or methods to 
achieve it, using sifting belts, sifting grids, sifting drums or sifting wheels. They are 
entered using words and diagrams in each of the four sqaures following the sift square.

The chart thus contains the six functions and 4, 4,3,4,4,3 ways of achieving each function. 
Thus, theoretically there are 2304 possible different potato harvesting machines, combining 
the various means. However, many of them are not viable. A machine that uses 
3,1,1,2,3,1 methods is a possible solution. At least four to five of such combinations will be 
identified for building the system.


\def \epsfsize#1#2{0.7#1}
\begin{figure}
\epsffile{../figures/7-4.eps}
\caption{Potato Harvestor}
\end{figure}

\def \epsfsize#1#2{0.7#1}
\begin{figure}
\epsffile{../figures/7-4b.eps}
\caption{Potato Harvestor}
\end{figure}


\subsection{Automatic can crusher}
The design team now lists all the functions that must be accomplished.  Then they generate a matrix
that has the functions on the right column, and they pointed out different ways to acheive these functions.  It
should be emphasized, here, that creativity should be exerised during this activity.  One may list the
different possibilities in text or in sketches. Both methods are exercised in this situation.  The available power
sources are:
\begin{itemize}
\item Hydraulic
\item Magnetic 
\item Gravity
\item Thermal
\item Sound
\item Pneumatic
\item Solar
\item Electric
\item Combustion
\end{itemize}

\def \epsfsize#1#2{0.7#1}
\begin{figure}
\epsffile{../figures/7-4c.eps}
\caption{Morphological Chart}
\end{figure}

\def \epsfsize#1#2{0.5#1}
\begin{figure}
\epsffile{../figures/7-4d.eps}
\caption{Morphological Chart (cont.)}
\end{figure}

Several designs can be generated from the morphological chart.  Five concepts are sketched here.

\section{Problems}
\subsection{Team Activity}
Consider the statement you worked on previously in a class team activity. 
 By looking at your objective tree, generate a list of specifications and house
 of quality for the statement.  Develop a morphological chart and evaluate the
 alternatives.
 
 
 If you drive in the state of Florida, you may notice some traffic congestion due to the trees being trimmed on the state roads and the
     freeways. Assume that the Florida Department of Transportation is the client. Usually, branches 6 inches or less in diameter are
     trimmed. The allowable horizontal distance from the edge of the road to the branches is 6 ft. The material removed from the trees must
     be collected and removed from the roadside. To reduce the cost of trimming, a maximum of only 2 workers can be assigned for each
     machine. The overall cost, which includes equipment, labor, etc. needs to be reduced by at least 25\% from present cost. The state claims
     that the demand for your machines will follow the price reduction, i.e.,
      if you are able to reduce the cost by 40\%, the demand will
     increase by 40\%. Allowable working hours depend on daylight 
     and weather conditions.   
     


