• Concept generation is where possible design solutions are first envisioned. This is where engineers use creativity and imagination to develop approaches to achieve the design objectives while satisfying the constraints.
• Concept generation requires a creative, unconfined, uninhibited mindset dedicated to conceiving new designs. This is the deepest part of the design swamp, but it is also the richest because it contains numerous unusual and exotic plants and animals. If we think of each one of these elusive species as a design idea waiting to be realized, this can be the most exciting and fulfilling aspect of the engineering design experience.
• Examine the opportunities for creative concepts to be incorporated into different kinds of engineering design assignments. Then we examine the meaning of creativity and the process of creative thinking.
• Identify the barriers to creative thinking and provide a set of techniques designed to help overcome those barriers.

Not all engineering design assignments require the same degree or type of creative thinking. In this section, we discuss one approach to classifying design problems according to the opportunities they present for innovative and creative solutions. While most real design activities involve combinations of the categories described here, it is still useful to consider them one at a time.

• Selection Design. For this category of problems, design involves selecting standard components from a vendor and assembling them in a straight-forward manner to achieve the design objectives. The components frequently are selected from vendor's catalogs that describe all the relevant characteristics of the components. These Standard components may include gears, valves, actuators, fasteners, sensors, motors, pumps, extruded shapes, structural beams of various cross-sectional sizes and shapes, electric circuitry, springs, switches, and bearings. You would be surprised at the rich and varied array of components and systems that are available "off the shelf"
• Configuration Design. Configuration design generally involves standard components, similar to "selection design," but the design challenge is to locate and arrange the components to improve performance or reduce size. An example of this is the design challenge of locating the jet engines on a commercial aircraft. The most popular configurations consist of the engines suspended beneath the wings, or cantilevered off the side of the rear fuselage, or mounted in the tail assembly. Even though many of the components are standard "off the shelf" items, there generally are areas in the configuration design category for modifying the size or shape of the components in order to take advantage of particularly attractive configuration opportunities.
• Parametric Design. Parametric design refers to problems in which the primary design challenge is to vary the performance or design parameters to achieve the design objectives. These parameters may be imbedded in equations which express the relationships among the parameters, the objectives, and the constraints that must be satisfied. Boeing uses parametric design to create an entire family of aircraft based on one basic design. Consider the many models of the 737, which is the best selling aircraft in history. The variety of the models was obtained by varying the fuselage length, wingspan, and engine characteristics to create various combinations of range, speed, and carrying capacity. Compared to selection design and configuration design, parametric design provides greater freedom to the engineer to examine different sizes, shapes, and other key parameters.
• Original Design. This category refers to the design of objects and systems that are a substantial and fundamental departure from existing products or processes. The push-button telephone is an example of a sudden, major, innovative departure from the rotary dial telephone. Other examples of breakthrough original designs include the personal computer, the microwave oven, the automatic transmission for automobiles, prestressed concrete structures, the elevator, the transistor, and the laser. Because the designs in this category involve radical changes from the existing norm, the creative element is a major, if not the dominant, factor in the design process.

Many people have studied the phenomenon of creative thinking. Some psychologists devote a substantial part of their careers trying to understand what distinguishes the creative person from the individual who rarely, if ever, comes up with a new idea. There are no definitive answers, but there are at least some indications of factors that appear to affect our creativity.

Creativity is an elusive concept, and there have been many definitions proposed by professionals in the field. Davis organizes definitions of creative thinking into four groups. The first group deals with the concept of combining ideas: for example, "Creative ideas are new combinations of previously unrelated ideas". The second group of definitions emphasizes the originality of the ideas, as typified by this definition attributed to Herbert Fox: "The creative process is any thinking process which solves a problem in an original and useful way". Next are those definitions which emphasize the unexplainable nature of the creative process, such as Carl Jung's assertion that, ".... the creative act... will forever elude... human understanding". The last group of definitions discussed by Davis are those that propose the idea that the creative act is inherently a product of the unconscious mind. For our purposes, we can be content with the insight provided by this range of definitions. We have no need to select from among them, or to consolidate them into a single composite definition.

These are not rigid linear models; the steps may come out of order, be skipped entirely, or be revisited. We will see that there is substantial overlap between these psychological models of the creative process and our model of the engineering design process. Under our model of engineering design, creativity is part of concept generation, and concept generation in turn is just one of nine steps in the design process. However, as we will see, the creative process models include elements that correspond to steps in our design model other than the concept generation step. We will handle this by presenting the creativity models in their entirety and indicate where they overlap those other elements of our engineering design model.

• Wallas model.
• This is a four-step model originally proposed in 1926.
• Preparation: This stage includes clarifying and defining the problem. It corresponds to Steps 1 and 2 in our model of the design process.
• Incubation: This is the formative stage which takes place while the mind is relaxed and the individual is engaged in an unrelated activity which frees up the conscious and perhaps unconscious mind to be in a receptive mode.
• Illumination: This is the conscious recognition of the new idea, the so-called "Eureka" phenomenon.
• Verification: This is the reality check to determine whether the idea has merit. It corresponds to what we called the Evaluation Step in our engineering design model.
• If we strip away those stages that are accounted for elsewhere in our engineering design model, we are left with a two-stage (incubation and illumination) model of the creative process.

Fabun model.

First proposed in 1968, this model uses the four stages from Wallas and adds three more.

• Desire: This deals with a thinker's equilibrium being disturbed by a problem. The individual then becomes motivated to restore the equilibrium by solving the problem. This sounds like Step 1 in our model of engineering design.
• Preparation: This is the same as in the Wallas model. But with the addition of the Desire stage, the Preparation stage now fits better with our Step 2. So the combination of the Desire and Preparation stages corresponds to what we call Problem Formulation. .
• Manipulation: This is where the mind actively manipulates materials or ideas in an exploratory fashion. This may include what we refer to as Step 4: Gathering Information. But it goes beyond that and represents the active effort that usually precedes the Incubation stage.
• Incubation: This is the same as in the Wallas model.
• Intimation: This is the feeling that you get when you realize that you are on the right track and are making progress.
• Illumination: This is the same as in the Wallas Model
• Verification: This is also the same as the Wallas Model.

Removing the overlap with our engineering design process model leaves us with a four-stage model: Manipulation, Incubation, Intimation, and Illumination.

Proposed in 1976 by the Creative Education Foundation (CEF), this model consists of five stages. Each step involves both a divergent phase in which options are generated, and a convergent phase in which those options are winnowed down and combined or modified. Only the best of those ideas are taken forward to the next phase.

• Fact Finding: This consists of collecting facts which might have some bearing on the problem. This appears to be Step 4 of our design process model-Gathering Information.
• Problem Finding: This begins with developing alternative statements of the problem. This is the Problem Formulation phase of our engineering design model-Steps 1 and 2.
• Idea Finding: This is where possible solutions are first presented.
• Solution Finding: This is the evaluation phase. It closely corresponds to a combination of Step 6: Evaluation of Alternatives and Step 7: Decision Making.
• Acceptance Finding: This phase is the counterpart to our Step 8: Implementation.

After stripping away the overlaps, what remains is a single-stage model of the creative process-Idea Finding.

• We will combine the non-overlapping elements of the three models described above into a consolidated model of the creative process. From the Wallas model, we take the Incubation and Illumination stages. The Fabun model contributes, in addition, the Manipulation and Illumination stages. However, we combine the Manipulation stage with the Idea Finding stage of the CEF model and rename it the Exploration phase. The result is the following four-stage model:
• Exploration: The active and concerted search for new ideas, often terminated frustration because of the inability to identify sufficiently attractive ideas
• Incubation:The extended period of relaxation during which there is no conscious effort to address the problem
• Intimation:The resumption of purposeful pursuit combined with the feeling that you are beginning to make progress
• Illumination: The breakthrough that produces an attractive new idea

Creative time is not the time to be conservative, analytical, and fearful of failure, since these attitudes can only inhibit you. Remember, in this phase of design our focus is on generating new ideas. Assessing the value of those ideas is a subsequent activity. Let's not jump the gun and confine ourselves to ideas that we think are workable We have plenty of time to discard or modify ideas. So let's do one thing at a time. Let's emphasize the generation of ideas at this point. Our awareness of the attitudes that can help sharpen our creative tendencies can be reinforced by understanding a little bit of the physiology of the human brain.

The human brain is a marvelous and mysterious organ. It is the home of our "mind" and the source of all our thinking abilities. Extensive research on the physiological structure of the brain has revealed that different parts of the brain are associated with different modes of thought.

Now that we have some familiarity with basic concepts of creative thinking and with the attitudes that can improve our creativity, "Why aren't we more creative? The answer to this question has two parts. First, most of us are continuously immersed in and surrounded by very strong barriers to creative thinking. Some of these are self-imposed, others arise from external factors. Second, overcoming these barriers takes a concerted effort.

Some of the existing barriers to creative thinking include perceptual barriers, cultural barriers, environmental barriers, emotional barriers, and intellectual barriers. Once we understand the nature of these barriers, we can focus on reducing the extent which they interfere with our mental preparation and inhibit our creative thinking.

• Perceptual barriers. Perceptual barriers prevent a clear understanding of the design problem and/or the opportunities for solutions.
• Cultural barriers. Cultural barriers are restrictions imposed by society. They discourage nontraditional approaches that violate societal norms.
• Environmental barriers. Anything in your immediate surroundings which inhibits creativity is an environmental barrier. This includes poor lighting, interruptions from frequent telephone calls, background noise, distracting aromas (both pleasant and unpleasant), uncomfortable temperature, or an uncomfortable chair. Environmental barriers are not just physical. The attitudes of your peers or your supervisors may be inimical to a creative thinking environment. Coworkers or bosses who are overly critical, who have no sense of humor, and who insist on rigid rules of dress and behavior can discourage your creative tendencies.
• Emotional barriers. Emotional barriers are feelings which discourage you from considering a solution, or distract you from focusing on the problem. Discomfort with the risk associated with a proposed solution may cause you to discard that solution prematurely. For example, if you lost a relative due to a firearm accident, you may be uncomfortable working on projects dealing with explosives. Recognizing the existence of emotional barriers is an important first step in overcoming them.
• Intellectual barriers. Intellectual barriers occur when you don't have enough knowledge of a topic to incorporate it into a design. Successful engineers overcome these barriers by remaining up-to-date in their field. You can't know everything, but you can expand your personal knowledge base by interacting with colleagues who have diverse backgrounds.

• Of the five categories of barriers mentioned above, perceptual barriers are the most common and the most difficult to recognize and overcome. Perceptual barriers manifest themselves when we perceive design problems too narrowly and thus become captive to an unnecessarily constrained perspective regarding possible solutions. Here we will examine five different ways in which this phenomenon can occur.
• Patterns. Many design assignments involve making incremental changes in prior designs. Much technological progress has been made though these evolutionary developments. The internal combustion automobile engine is an excellent example of the impressive results achieved using the incremental approach over approximately one-hundred years. However, there also are situations that could be improved by making a radical departure from an existing pattern instead of continuing with incremental improvements. The phenomenon of existing patterns of thought serving to inhibit our creative tendencies is well known, and can even permeate entire organizations. The corporate "way of doing things" may serve a company well for a period of time, but can paralyze the firm when new circumstances require a rethinking of basic design philosophy. Keuffel & Esser dominated the market for slide-rules but was unable to adapt to the era of pocket calculators. Several mainframe and mini-computer manufacturers went out of business because they failed to appreciate the significance of the desktop personal computer.
• Boundaries. Another barrier to letting loose our creative juices is our tendency to interpret situations too literally and impose artificial boundaries on the range of solution possibilities. Many people take for granted that certain restrictions or boundaries exist. These perceived constraints can serve to severely limit the possibilities for creative solutions.
• Illusions. The fact that we don't always perceive objects correctly is the basis for many optical illusions. We act too quickly on our first impression of an object or situation, we may misinterpret the situation or at least ignore alternative explanations.
• Lenses. Another kind of perception barrier arises when we look at situations with the wrong lens or focus too much on details. When this occurs we often miss the larger picture (we can't see the forest for the trees).
• Meanings. A perceptual barrier arises because we tend to adopt conventional roles for objects. We severely limit our options if we fail to consider the possibilities that become available if we adopt new interpretations for the role of familiar objects. The objects we refer to here can also include words, since relying only on the conventional meaning of words can also unnecessarily restrict our opportunities for creative solutions.

Understanding the nature of creative thinking and the barriers that serve to inhibit it are a good start towards enhancing our creative capabilities In this section we take the next step by learning several techniques that are designed to help stimulate our ability to generate design alternatives. Before discussing specific techniques, we want to emphasize two extremely important principles that should govern all your concept generation activities.

• Lateral Thinking. Thomas Edison said, "It's easy to obtain one hundred patents if you also have 5,000 unsuccessful inventions". A fundamental principle of the concept development phase of design is to concentrate on generating a large number of aternatives. The corollaries to this principle are: (a) resist the urge to pursue any one of the concepts in detail; and (b) avoid critiquing any of the concepts.
• Perseverance. A myth about creativity is displayed in the cartoon of the light bulb going off above somebody's head to signal the instant creation of a new idea. Much closer to the truth is that many new ideas are the result of a gradual evolution of thinking about existing concepts in new ways. While light bulbs occasionally do flash, they usually are the end result of a long process of searching. Thomas Edison is alleged to have said, "Invention is 95% perspiration and 5% inspiration." Many people find that an extended, conscious, dedicated search for new ideas is often unsuccessful, but that it prepares the necessary background for a new idea that is born during a period of relaxation. The key factor appears to be that these breakthroughs are more likely to occur if they follow' an extended, intensive, conscious effort.
• Mental Push-ups. Athletes engage in regular physical exercise between athletic events as a way to stay in shape. Though football players never do push-ups in a game situation, they engage in a regular and rigorous routine of push-ups and similar exercises in order to keep in top physical condition. It should not be surprising then that a regular routine of mental exercises can keep your creative thinking powers in top form. Several versions of "mental push-ups" to keep you in peak creative condition include: making lists, word games, solving puzzles, magic tricks and other games.

Now that we have practiced our "mental push-up" exercises diligently, it is time to implement our game strategies. These are approaches to use in actual design situations. The first set that we will discuss provide a structure to enhance the creative productivity of design groups.

• Brainstorming. Brainstorming is a structured group-oriented technique for conceiving design alternatives. It consists of a group of individuals letting their imaginations run wild, but in accordance with certain procedural rules. The hope is that the group members will inspire and support each other; as a result the group will be able to conceptualize design alternatives that are more elegant than any that the individuals could have achieved independently. The objective of a brainstorming session is to generate as many design concepts as possible. Individuals should be encouraged to mention all their ideas: the more outrageous, the better. Understandably, many people are reluctant to suggest design concepts that they may not have thoroughly thought through. In particular, many people may not be willing to risk eliciting negative reactions from other members of the group. Another important brainstorming rule is that ideas may not be pursued in detail. Once the basic gist of the idea is clear, the group should resume the search for other ideas. Group members must resist the urge to inquire about details of specific ideas. There will be plenty of opportunities to do that at a later time. The emphasis must be kept on generating as many ideas as possible, without worrying about their details, or even their validity.
• Brainwriting. This is a variation of the brainstorming approach. Instead of ideas being presented orally, each participant writes their ideas on slips of paper, and the slips of papers are circulated among the group. The brainwriting technique preserves the anonymity of the individuals, and prevents .the more vocal personalities from dominating the session. A computer-age twist replaces the slips of papers with personal computers connected via a local area network, while still preserving the anonymity feature. Because the personal interaction is less direct and spontaneous in comparison to the traditional brainstorming approach, there may be less synergism of ideas.
• Storyboarding. Storyboarding is another variation of brainstorming. The main feature of this approach is the format and media for recording and organizing the ideas that are generated. In this method, participants write each of their ideas on cards. All cards are then collected and tacked or pasted on a wall. After all the cards have been posted, the group engages in a discussion of the proposed concepts that can lead to many of the cards being grouped into categories. While story-boarding suffers from the same spontaneity weakness as brainwriting during the early part of a session, the ability to move cards around on the wall fosters an exploratory atmosphere for synthesizing and modifying the initial set of ideas.

• The techniques just presented describe processes, formats, and procedures to help elicit creative ideas. However, there are many times when, in spite of using the best techniques, the ideas are just not forthcoming. Here are two practical approaches to breaking the impasse and stimulating your creative juices. Both approaches rely on the notion that creative thinking involves making connections between situations that at first glance are not connected.
• Random stimulation. This approach relies on selecting a word at random (say, from a dictionary, or the daily newspaper, or a magazine) and then using word association or a sequence of word associations, to suggest an idea for a design alternative. Don't give up until you've allowed for a reasonable incubation period. Second, exert the discipline required to stick with each application of the random stimulation method. Giving up too easily may deprive you of the pleasure of generating some very unusual options. Remember, the stimulus does not have to be a word. Photographs, objects, or paintings, can also be used.
• Analogies. Another approach to fostering the generation of concepts is the use of analogies. This technique encourages the participants to see the similarities between the given design situation and another situation. The idea is that it may be easier to generate ideas for that other situation; some of which may be transferrable to, or adapted for, the present situation. A four-step approach to using analogies to generate design concepts is listed here: State the need, Generate the analogies by completing the phrase, "this situation is like ...; Solve the analogy; Transfer the analogy to the original problem.

• Morphological box. Another technique for developing new ideas is the morphological box. Each function or attribute is assigned a dimension in an array. The various design options for each attribute or for accomplishing each function are listed along the axis in the respective dimension. Morphological boxes can be constructed at several levels of detail. They can also be used in layers, to pursue selected options in more detail. The morphological box technique provides a structure that encourages design engineers to consider all possible combinations of functions and attributes, not just the most obvious ones. As such, it is a useful graphical tool for engaging in lateral thinking. Its primary shortcoming is that it is limited to simultaneous consideration of no more than three characteristics.
• Morphological charts. Morphological charts are a modification of the morphological box concept that removes the restriction on the number of attributes or functions that can be depicted. This is accomplished by listing each attribute or function in a single column. The options associated with that characteristic are listed horizontally in the corresponding row.

This exploration of the creative process has provided insights and given us tools that can help us heighten our individual creative powers. Perhaps the three most important lessons to take away from this lecture are that:

• The concept development phase of design should focus on generating a large number of options, and postponing judgment on their viability;
• It is possible to improve individual and group ability to generate creative solutions to design problems; and
• To be successful in our efforts to be creative requires a great deal of effort, discipline, practice, and a supportive working environment.