Concept generation, getting the ideas, is the most critical step in the engineering design process. Starting with a set of customer needs and target specifications, the process concludes with an array of product alternatives from which a final design is selected. There are multiple steps involved in the generic concept generation process, as well as various approaches. This article reviews and critiques these different perspectives within the context of successfully developing an electronic medical product that is innovative in design and customer appeal.


Concept generation, which is when a product development team comes up with the ideas, is the most critical step in the engineering design process – without it, there is no design. A concept can be defined as both an “approximate description of the technology, working principles, and form of the product” as well as a “concise description of how the product will satisfy customer needs” (Ulrich & Eppinger, 2012). Concept generation is a procedure that begins with a set of customer needs and target specifications and results in an array of product concept design alternatives from which a final design will be selected. This step requires a more abstract style of thinking than perhaps most engineers are used to. As Einstein and Infeld (1938) wrote in The Evolution of Physics, the “formulation of a problem is often more essential than its solution, which may be merely a matter of mathematical or experimental skill. To raise new questions, new possibilities, to regard old problems from a new angle, requires creative imagination and marks real advance in science.” While many have proposed their own specific theories, approaches, and metrics regarding concept development and, in particular, generation, there are a few general guidelines and postulates that are echoed in each specific method. The common theme: patience and open-mindedness are vital to successful concept generation.

The invention of the light bulb highlights the importance of the concept generation process. Famous inventor Thomas Edison once said, “None of my inventions came by accident. I see a worthwhile need to be met and I make trial after trial until it comes. What it boils down to is 1 percent inspiration and 99 percent perspiration” (Newton, 1989). Edison understood that trying a large quantity of ideas was extremely important, because failure is inevitable. Before finding a stable material for the first successful light bulb, his lab tried and failed with thousands of different filaments (Zenios, et al., 2010). Obviously, the concept that was settled on stuck, because well over 100 years later, commercially available light bulbs are omnipresent.


Figure 1

Thomas Edison’s patent drawing and application for an improvement in electric lamps, 1/27/1880; Records of the Patent and Trademark Office; Record Group 241; National Archives [retrieved from the Access to Archival Databases at www.archives.gov, April 24, 2013].

The Yellow Team, the 2012-2013 Tufts ECE senior design group that served as a case study for this article, faced the added complexities and challenges involved in designing a medical device for their project, which was to digitize an outdated device utilized in assessing glaucoma. Invention is a very intricate process, perhaps more so in the design of medical devices than in most other fields because there are so many factors that must be considered. Some upstream issues include: medical need, gaps in the treatment landscape, stakeholder interests, and market opportunity. Some downstream concerns are: patenting, regulation, reimbursement, and deployment in the healthcare system. Successful concept generation is critical for building a reliable product that will be able to satisfy many multi-faceted requirements.

There are two components in the concept generation stage: ideation, and then concept screening. Each component comes with its own set of rules and guidelines. Yet we can combine and break down the whole stage into a generic five step process.

Step One: Clarify and Deconstruct the Problem

Before coming up with any possible solutions, familiarization with some background information may be necessary. Perhaps the most important in a situation where people are looking to develop a solution to needs, the needs specification and problem deconstruction forms the foundation of this background information. For example, the Yellow Team found it important to have an overview of existing treatment options and a basic understanding of electronics and sensors in order to facilitate their flow of ideas and discussion. It is also really critical to decompose a complex problem into simpler sub-problems.

One can look at a product in development as a system. Many transactions occur relating to this system – what are the inputs being given from the user to the product, and what are the outputs being received? This analysis is important to understand the dependencies and the risks involved with the product, and help determine what needs to happen in between. The “in-between stuff” are the sub-problems. Systems engineering is a means to enable the realization of successful systems. It focuses on defining customer requirements and necessary functionality before proceeding with design synthesis and system validation while considering the complete problem.

Figure 2

System Engineering Tasks.  Source: Lasser (2012).

A system engineering diagram can help one look at the big picture, identify the modes of failure, and ultimately optimize the performance of the system. A system engineering diagram increases a system’s probability of success. It helps clarify, for the designer, what the system specifications are. It also helps clarify for the designer which features, functionality, and requirements are unnecessary and can be eliminated. This, in effect, means reduced total development costs and cycle time, as well as overall functional reliability. The Yellow Team’s system engineering diagram (Figure 3) is an example.

Figure 3

Tufts ECE 2013 Yellow Team’s System Engineering Diagram.  Source: Ferrentino at al (2013).

Once the problem has been defined and effectively broken down, initial efforts should be focused on critical sub-problems.

Step Two: Search for Solutions

Searching for Solutions Externally

An external search is an information-gathering process. It should be performed to find existing concepts relating to both the overall problem and to the sub-problems identified during the problem clarification step. Implementing an existing solution can be easier, cheaper, and much faster than developing a new solution. Another option is to optimize a pre-existing solution, or to apply it as-is to one sub-problem and pair it with an original concept for another sub-problem, combined to yield a novel and improved overall design.


Figure 4

Tufts ECE 2013 Yellow Team’s Reconstructed Tonographer Circuit.  Source: Ferrentino et al (2013).

As the Yellow Team learned the hard way, it is much more efficient to proceed with this search by first broadly gathering information that might be related to the problem and then focus the scope of the search by exploring more directed details. An imbalanced approach renders an inefficient external search. Some examples of good resources are the following: searching through patents and published literature – the Yellow Team performed this step throughout the first semester of the project, but found it a somewhat vague resource; benchmark related product – with the help of some department faculty advisors, the Yellow Team was able to recreate the circuit (Figure 4) of the device in order to fully understand it;  interviews with lead users, and consulting experts – the Yellow Team did this by working with an active ophthalmologist to determine the project requirements and finally narrow the scope.

Searching for Solutions Internally

Searching internally for solutions, also known as brainstorming, is an enormous part of successful concept generation. One important thing to keep in mind during this step is to be patient. Engineers love jumping to conclusions, but it’s important to be open to the unknown. Successful concept generation requires a new mindset that perfectionism “is the enemy”. As a result of contemporary education’s emphasis on immediate solutions and fact-finding, today’s engineers tend to neglect the consideration of different ideas. Zenios et al. (2010) said that “most of us like to solve problems and move on. Idea finding may seem childlike (and it should be) but at its heart is the exploration of possibilities, free from as many constraints as possible”. These opinions are not new. Osborn (1953), the alleged founder of brainstorming, claimed the following four tenets of brainstorming:

  • The judgment of ideas is not allowed
  • Outlandish ideas are encouraged
  • A large quantity of ideas is preferred
  • Members should build on one another’s ideas

IDEO, a contemporary global design consultancy, incorporated Osborn’s themes into a proposed set of rules to traditional group brainstorming (IDEO, 2011):

  • Defer judgment
  • Encourage wild ideas
  • Build on the ideas of others
  • Stay focused on the topic – minimize noise and don’t lose track of the focus for that session
  • One conversation at a time
  • Be visual – use props, have a scribe, and utilize doodles, diagrams, and buzz words in a logical way that illustrates your ideas
  • Go for quantity

Brainstorming describes a set of methods for creative problem solving, implemented in group settings as well as by individuals. The term was popularized by Osborn in his 1953 book, Applied Imagination, which launched the study of creativity in business development. The principles Osborn proposed over half a century ago hold just as true today: it is critical that participants – in any variation of a brainstorming session – set aside any preconceived notions or preemptively formed solutions and “temporarily suspend their instinct to criticize new ideas”. They must “open their minds to a creative flow” of new possibilities as well as look for original, even unusual, connections among the generated ideas. Critical filtering, while necessary and important at many points throughout product development including later in the concept development process, can be counterproductive to a team’s results when first considering solutions. It can be quite difficult for people in science fields, who are so accustomed to producing quick, correct solutions, to restrain from making snap judgments on new ideas. This is one of the many reasons why forming a multidisciplinary team and seeking unique, interdisciplinary perspectives for a group brainstorming session is extremely important.

Concept generation is enormously enabled by including a group of participants with diverse backgrounds, expertise, and perspectives. Establishing a multidisciplinary perspective is particularly paramount in developing medical devices, as opportunities for adapting technologies and approaches from one area to another arise so frequently in the medical technology sector:  between physicians and engineers, between different medical specialties, and even between medical and non-medical technologies (Zenios et al., 2010).

Group sessions are critical for building team consensus, communicating information, and refining concepts (Ulrich & Eppinger, 2012). Group sessions can also be useful by allowing any participant to build on the ideas of others. One person’s idea can stimulate the creativity of other participants to come up with the next level – a solution enhancement, a novel connection, or just some totally random idea that they would not have thought of otherwise (IDEO, 2011).


Figure 5

Tufts ECE 2013 Yellow Team Meeting and Discussing Ideas with Ophthalmologist.  Source: Ferrentino at al (2013).

There are some matters to consider when it comes to picking participants for a brainstorming session, especially when dealing with medical devices. For one, the deeply ingrained value of avoiding damage to patients makes physicians and engineers alike particularly conservative when it comes to pre-screening ideas, along with all their other knowledge and experience based biases. A second important action is to consider all of the areas that potentially will come into play in designing and developing a medical device solution. Find people who understand the field of interest and existing technologies, but also have the ability to see past their own knowledge so as not to bias the group toward a particular type of solution. An alternative approach is to turn this “expert problem” – having someone almost too knowledgeable come in with all of their biases and preconceived notions – into an advantage by bringing in an expert to lead some sort of working session can uncork the expert’s mind and arouse some interesting ideas. For the Yellow Team, this was the ophthalmologist who acted as both their project sponsor and lead user.

The Yellow Team and its project exemplify the inevitable interdisciplinary nature of such a product. The project required the efforts of all five team members, from a number of educational backgrounds.  The electronics required knowledge of biomedical engineering and electrical, specifically signal processing and processing sensor data. The two electrical engineers and the biomedical engineering double-major on the team were responsible for this section of the project work. Human computer interaction, specifically the user interface is critical to communicating the test results and making the device intuitive for use by trained medical staff. A human factors engineer and a computer engineer worked together to design a graphical user interface that provides functionality for ease of use.

Figure 6

Tufts ECE 2013 Yellow Team’s ECE Students at Poster Session.  Source: Ferrentino at al (2013).

Step Three: Systematically Explore the Solutions

Brainstorming may result in tens or hundreds of ideas that need to be screened, sorted, and then evaluated before any single idea can be chosen. Being selective about which concepts to pursue form the pile generated during the ideation phase is of the utmost importance. Concept screening involves organizing and analyzing all of the ideas. It is critical to understand how to cluster and organize the output of a brainstorming session so it can be presented and analyzed in a meaningful way. Grouping ideas can reveal potential gaps or biases in the proposed solutions, as well as opportunities to combine ideas into unique, synergistic ones that ultimately yield more optimal, cohesive, and complete solutions that better address the need than any individual concept. It is also crucial to learn how to objectively compare all of the possibilities against the defined need specification to determine which course to pursue based on how well each option satisfies the need.

Effectively organizing data before beginning concept screening primarily boils down to two activities: clustering and concept mapping. The first step to clustering is to identify the primary organizing principle on which the clustering pattern is based. This can be quite challenging, as there are always multiple factors that have significance and benefits in different ways.

Table 1

Organizing Principles prior to concept screening. Source: Von Hippel (page 196, 2004).

Organizing principle Description
Mechanism of action Group ideas according to how the solutions are intended to work.
Technical feasibility Group ideas according to the likelihood of coming to fruition. This is based on understanding what is feasible using current engineering and scientific methods.
Funding required Group ideas around the amount and/or source of funding required to develop them.
Affected stakeholder Group ideas around the stakeholder most affected, typically the patient or healthcare provider.

Another approach is to create an organize hierarchy, dividing big clusters into subgroups of smaller clusters based onto additional organizing principles, and so on, incorporating into deeper and deeper levels. After one or more organizing principles have been applied to clusters, the clusters can be documented in a concept map, also known as a mind map. A concept map illustrates how ideas relate to one another and to the main problem or need. These maps help the innovator recognize patterns and build connections. When developing a concept map, the need is placed at the center, with the clusters of ideas spanning in different directions. To be effective, an innovator must strive to ensure that all of the clusters have an obvious relationship to the need.

Screening is intended to filter the vast universe of ideas to the ones that best address the need. This requires rigorous comparison and analysis to the original need statement and the explicitly defined need criteria laid out in the customer specifications to see which concepts satisfy the requirements and which do not. It is essential to not lose focus of these original specifications. Any modification or compromising of the specifications may undermine the integrity of the screening process and lead to poor choices. Concept maps will lead to a greater understanding of the different parameters along which each solution is aligned. While not completely fail-safe, this method is a good attempt at objectively assessing the current state of the concepts. Remember that some solutions may meet the need criteria but still need to be eliminated from consideration because they are too impractical or infeasible given the circumstances, such as technology constraints, potential customer or user concerns, etc. Although relatively rare, if screening yields too many solid potential concepts rather than approaches that meet the need criteria, then the need criteria may be too broad, requiring the innovator to revisit the need specification to generate more specific criteria. Some additional tools that can be used are the concept classification tree, used to reorganize lists or mind maps by function, and the concept combination table, which provides a method for combining solution fragments systematically – each column in the table represents a sub-problem and each row a conceptual solution.

Step Four: Reflect and Refine the Solution

It is important to realize that the ideation and brainstorming steps of the process are not over once they are completed the first time – the concept generation process is cyclical. As new information and new circumstances continue to crop up at all stages of the process, the team may be required to go back into brainstorming mode, for example when refining the direction or approach on an already accepted solution. This process is a feedback loop. Good prototypes tend to provide powerful stimuli for new ideas. The relationship between prototyping and brainstorming is an iterative one.

Cited References