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Using TRIZ for an Engineering Design Methodology Course at NCTU in Taiwan

Using TRIZ for an Engineering Design Methodology Course at NCTU in Taiwan

| On 13, Mar 2000

Chen-Chu Tasi* and Ching-Huan Tseng**
Department of Mechanical Engineering, National Chiao Tung University
Hsinchu 30056, Taiwan, R. O. C. E-mail:
TEL: 886-3-5726111 EXT. 55155 FAX: 886-3-5717243

*Teaching Assistant
** Professor

This study depicts the preliminary use of TRIZ into the mechanical engineering course, engineering design methodology, at NCTU in Taiwan. The first offering of the course attracted 17 students that included undergraduates and graduates in the spring semester, 1999. The course covered the conventional design methodology and TRIZ methods. The research notebooks and the web patent database were used as tools for gathering and searching information during the entire semester. The students took lesson in the skills from this course to collect and analysis information, find and solve the problems, generate and evaluate the concepts, and sketch the final concept. The reports of the final projects were in the form of a patent. Some of projects are filed for the patents and some are published in TRIZ Journal.

Conventional Design Methodology

First of all, the tasks and procedures for the conventional design methodology were introduced in the course. Students should realize the main task of engineers. They apply their scientific and engineering knowledge to the solutions of technical problems. Then, they optimize those solutions within the requirements and constraints set by material, technological, economic, legal, environmental and human-related considerations [1] .

In view of the central responsibility of the designers for the technical and economic properties of a product, and the commercial importance of timely and efficient product development, it is important to have a good systematic design procedure to find solutions. Systematic procedures provide an effective way to rationalize the design processes, and therefore it can steer the efforts of designers from unconscious into conscious and more purposeful paths.

It is useful and common to divide the planning and design processes into the following main phases (Figure 1 [2] ):

Ÿ Planning and clarifying the task: specification of information

Ÿ Conceptual design: specification of principle

Ÿ Embodiment design: specification of layout (construction)

ŸDetail design: specification of production

Flowchart: Terminator: Task Market, company, economy

Figure 1 Design process [2] .

The detailed explanations for these phases were presented in the course. The planning and the clarifying task are combined into first phase of the design process. A successful design planning process always takes into consideration the market, the company and the economy. It is also necessary to clarify the given tasks in more the listing before starting design development. The second phase of the conceptual design plays an important role in the design process because it is extremely difficult or impossible to correct fundamental shortcomings of the solution principle in the subsequent embodiment and detail design phases. A lasting and successful solution is more likely to spring from the choice of the most appropriate principles than from exaggerated concentration on technical details. However, students encountered more difficulties in the conceptual design phase. In many cases the students known what’s the problem, but they didn’t know how to solve the problem. The methods of TRIZ are more effective and efficient than the conventional problem solving methods. Therefore, TRIZ methods were introduced into the course.

Theory of Inventive Problem Solving (TRIZ)

For a start, the differences between the thinking patterns of adult, child and TRIZ-trained minds were compared, and Dr. Altshuller, the history of the Father of TRIZ, was introduced. The materials in the references [3-5] are used to teach in the course. The introduction and some examples inspired the students’ interests. To prevent students from being mystified by the complete algorithm of TRIZ, a simplified form of TRIZ and the TRIZ software, Invention Machine’s TechOptimizer V3.0 [6-7] , was introduced. TechOptimizer includes three main “Analytical Tools” and four main “Problem Solving” tools that help synthesize directions to potential solutions. These 7 tools are Production Analysis, Process Analysis, Feature Transfer, Internet Assistant, Effects, Principles, and Prediction, shown in Figure 2.

Figure 2 IMC’s innovation roadmap [6] .

The Effects module is a comprehensive engineering knowledge base that contains a library of over 4,000 effects and examples that combines physical, chemical, and geometric laws, theorems, phenomenon, and alternative methods to solve technical problems. The effects are organized to let users easily find solutions to functional problems or requirements. The Principles module is an enhanced and computerized version of the matrix of the contradictions that Altshuller synthesized to help engineers be more creative in solving engineering problems. It also provides the animations, brief descriptions, and examples of the 40 principles. These are very helpful to understand and choose the principles. The Prediction module incorporates the trends of the technological evolution that were extracted from the patents analyzed. It helps students solve a problem by guiding users along the prediction tree comprised from these empirically derived trends.

The simplified form of TRIZ and the TRIZ software let student get started, and used TRIZ successfully. After learning the TRIZ methods, the students recognized their mental changes. They removed the mental constraints of existing solutions and could think “out of the box”. This is a very obvious and positive effect of TRIZ.

Research Notebook

Some nations adopt the principle of first-to-invent for the patent system. When a dispute about the date of the invention rose, the research notes can be introduced to be the evidences. On the other hand, the research notebooks are helpful to capture the fleeting inspirations, and accumulate as well as impart the experiences and skills. Therefore, it is necessary to carefully put down the whole processes for the students from the concept development to put into practice for protecting the proprietary rights of the inventors or companies.

The research notebooks are provided for the students in the beginning of the course. The students are taught how to use and write it. An explicit instruction is also included in the first two pages of the notebook. They could write down everything related to the course and their design processes on their own research notebooks that would be a part of their scores.

Importance of Patent

According to the statistics by the World Intellectual Property Organization (WIPO), the patents cover 90% ~ 95% of the worldwide research results; and further, making good use of the patents would reduce 60% of the research time and 40% of the research costs. Therefore, patents are the very important resources in the step of information gathering. A procedure for patent analyses is provided to help the students to make good use of the patents in Figure 3. There are many webs that offer accesses to full-text patent database, even including images. With powerful search features, they offer maximum results with minimal effort. Some of the webs are listed in Table 1. Almost all of the students search and gather information by the webs in this course.

Figure 3 A procedure for patent analyses.

Table 1 Web patent database.




The US Patent and Trademark Office (USPTO) web patent database (free)


U.S. patents, Espace-A (Applications), Espace-B (Issued), Patent Abstracts of Japan, and WIPO PCT Publications (free)


U.S. patents, European A (1987-present) and B (1991-present) patents


Chemical patents


U.S. and Europe patents


U.S. and Europe patents


Derwent Patent On-line


R.O.C. patents


R.O.C. patents

A checklist of patent study is as shown in Figure 4 for an example of a child car seat, which includes the important information of a patent. The checklist is brief and to the point. An art-function matrix of the car seat is as shown in Table 2. It is a two-dimensional arrangement. The function of the patent is listed along the vertical axis and its art is listed along the horizontal axis. The intersection of the function and the art is the corresponding patent number. After studying the useful patents and filling in the checklists of patent study as well as the art-function matrix, these are very important references for applying for a patent, and further, they are helpful to understand the infringement risks and design around patents.



Child restraint seat assembly

Patent No.


Date of Filed

Feb. 14, 1996

Date of Issued

Oct. 7, 1997


Frazier Innovations, Inc.


Frazier; David Keith


C. C. Tsai

Date of Analysis

Sep. 10, 1999

Prior Art:

1.The previous child safety seats require a separate seat, or a separate space on a seat to which they are attached.

2.None of the prior art devices disclose a device for securely maintaining a child in the lap of a seated adult.


Maintain a child in the lap of a seated adult securely.


Improving the safety of “lap babies” and saving the cost of an entirely separate seat.

Ways and Important Figures:

A child restraint seat assembly 10 is provided for use in securing a child within a safety seat that is secured to the seat belt 12 of a seated adult. The child restraint seat assembly 10 includes a seat having a bottom and a back, the bottom having a front end and a rear end, and the back having a top end and a bottom end. The bottom end of the back is joined to the rear end of the bottom. Additionally, the child restraint seat assembly includes at least one elongated strap 20 adapted to secure the body of a child to the seat. This strap 20 further includes a plate attached to the strap which can be removably attached to a plate receiving member 28 attached to a post 30. The post 30 is secured to the front end of the bottom of the seat assembly. The plate receiving member 28 further includes a plate release 31. Additionally, the seat assembly 10 is removably attached to a seat belt 12 worn by a seated adult by a loop 32 attached to the post 30, the loop 32 being adapted to slidably engage the seat belt 12 therethrough. The loop 32 further includes a hinged portion 34 so that the seat assembly 10 can be removed from the seat belt 12 while the seat belt 12 is still secured around the seated adult.


1.A child restraint seat assembly comprising:

a seat having a bottom and a back, said bottom having a from end and a rear end, said back having a top end and a bottom end, said bottom end of said back being joined to said rear end of said bottom,

means attached to said seat for removably securing a child within said seat, and

means secured to said seat for removably attaching said seat to a seat belt of a vehicle seat, said means secured to said seat for removably attaching said seat to said seat belt comprising a loop directly attached to a post, said post attached to said front end of said bottom of said seat, said loop adapted to slidably engage said seat belt therethrough.


Figure 4 A checklist of patent study for a child car seat.

Table 2 An art-function matrix of the child car seat.




Ball +

Arc Groove

Cam +

Spring + Teeth +

Lever + Bar

Slider + Recess + Groove

Recessed Wall + Aperture + Plate

Bar +


Position Indicator



Tightening strap



Safety-strap guide


US5,954,397 US5,964,502

US5,458,398 US5,286,086

Spring-back prevention



Final Projects

First, the students decided the topics of the final project by themselves. Then, they used what they learned in the course to collect and analysis information, find and solve the problems, generate and evaluate the concepts, and sketch the final concept. The reports of the final projects are in the form of a patent. Parts of the project topics were listed as following:

  1. An integrated steering shaft lock for motorcycles.

  2. Conceptual design for brake shoes of a bicycle [8] .

  3. A shifting device for synchronous controlling front and rear derailleurs.

  4. Conceptual design on continuous variable transmission (CVT) for bicycles.

  5. A quickly and reliably method for opening envelopes [9] .

  6. Open-end ratcheting wrench.

  7. Metal seats for ball valve.

  8. Electromagnetic mechanical impedance sensors.

Some final reports of the student’s projects are innovative and patentable. First and second topics of the listing above are filed for the patents and second and fifth topics have been published in TRIZ Journal [8-9] . Therefore, it can be considered this to be an indicator of successful delivery in this course.


  1. G. Paul and W. Beitz, “Engineering Design: A Systematic Approach”, Springer, 1995. (Textbook)

  2. D. Ullman, “The Mechanical Design Process”, McGraw-Hill, 1992.

  3. J. Terninko, A. Zusman, and B. Zlotin, “Systematic Innovation: An Introduction to TRIZ”, St. Lucie Press, 1998. (Textbook)

  4. G. Altshuller, “And Suddenly the Inventor Appeared”, Technical Innovation Center, Inc., 1996.

  5. G. Altshuller, “40 Principles TRIZ Keys to Technical Innovation”, Technical Innovation Center, Inc., 1997.

  6. “TechOptimizer Version 3.0 Software Manual”, Invention Machine Corporation, 1998.

  7. Y. C. Hsiao, “TechOptimizer Training manual”, Flotrend Corporation, February, 1999.

  8. C. P. Chiang and C. H. Tseng, “Development of Conceptual Design for Brake Shoes of a Bicycle by Using TRIZ”, TRIZ Journal, October, 1999.

  9. J. L. Chen and C. H. Tseng, “Case Studies In TRIZ: A Quickly and Reliably Method for Opening Envelopes”, TRIZ Journal, August, 1999.