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USE OF THE THEORY OF INVENTIVE PROBLEM SOLVING (TRIZ) IN DESIGN CURRICULUM

| On 12, Mar 1997

published in Innovations in Engineering Education, 1996 ABET Annual Meeting Proceedings, pp.161-164.

Eugene I. Rivin, Professor of Mechanical Engineering
Wayne State University, Detroit, MI 48202
Victor R. Fey, The TRIZ Group, Southfield, MI 48076
TRIZGR@aol.com
Abstract

The paper describes use of the Theory of Inventive Problem solving (TRIZ) as a tool of enhancing creativity of Mechanical Engineering students at Wayne State University. Besides a special elective course on TRIZ, this methodology is incorporated into the graduating “capstone” design course.

Key words: creativity; design; problem solving.

Introduction

“Creative Thinking” is one of the most important issues to be addressed in engineering education. However, emphasis of many engineering curricula is moving steadily towards increasing role of computers. While computers and such computer-based techniques as CAD, CAD/CAM, FEA are very powerful tools significantly improving productivity of practicing engineers, they do not help much in developing novel concepts while engineers are solving design and manufacturing problems. It is well known that our overseas competition, both across Atlantic and across Pacific, frequently have much less computers but develop better designed and more competitive products in a shorter time.

There is a definite need to give students some guidelines for creative thinking and some experience for formulation and conceptual solving of design and manufacturing problems. If this effort were successful, then effectiveness of computer applications would be also enhanced.

These goals can be achieved by application of the Theory of Inventive Problem Solving (TRIZ in its Russian abbreviation) which was developed in the former Soviet Union by G. Altshuller. This is an algorithmic methodology which allows for breaking psychological inertia in problem solving. It also provides engineers with powerful algorithmic approaches to formulate, analyze, and solve complex engineering problems, as well as to use objective Laws of Evolution of Technological Systems for directed development of new generation of products.

TRIZ had been developed in the fifties and after that was continuously modified to become a comprehensive problem-solving methodology. One book by Altshuller was translated (very poorly) into English in 1984 [1]. In 1991 the first author observed a demonstration of a TRIZ-related software and then organized a seminar at Wayne State University for Detroit-based manufacturing companies which was presented by two Russian TRIZ specialists. This seminar was the beginning of WSU involvement in TRIZ education and training. A brief description of TRIZ was published in 1994 [2].

TRIZ is much more than a problem-solving methodology. After several offerings of the course on TRIZ at Wayne State University, it became clear that the most important impact of this course is in changing mentality of the students. It looks like the students understood it too. However, while TRIZ is fast becoming more and more popular and several TRIZ-related software packages are on the market, it is frequently underestimated that TRIZ is a mindset, not just a collection of powerful solution techniques.

What does this ‘changing mentality ‘ mean? Majority of our students and all participants of short training courses are working, frequently, at large companies (in Detroit – mostly car manufacturing and automotive supplier companies). The climate in these companies is such that the natural creativity is not encouraged but rather suppressed. There are several factors responsible for this. One is overabundance of computers and the unwritten belief that they can solve problems; another is a rigid hierarchy which limits initiative of young degreed or non-degreed engineers. Yet another factor is a fear of failure. While the announced corporate policies are always “don’t be afraid of failures, learn by them,” in real life the attitudes are very different. As a result, many students and engineers attending short courses are very close-minded. In the beginning of a course, even simple (but strangely looking) problems do not generate much response. Students are afraid to offer solutions or even questions about the problem, since it might be a wrong suggestion or a stupid question, and they would “lose face.” The TRIZ training gives the participants an ssurance that they are able and capable of tackling (and, frequently, solving) any tough, unusual, and complex problems. Their minds are opening , they are not afraid. Even weak students are changing noticeably.

In accordance with these views, we developed a TRIZ-training approach which emphasizes ideology of TRIZ rather than training on application of software to solve practical problems. The practical problems are solved in the course of training, but by using ARIZ (Algorithm for Inventive Problem Solving), Standard Solution Approaches, The Laws of Evolution of Technological Systems, and other basic techniques of TRIZ. TRIZ can be compared with such powerful engineering methodologies as CAD and FEA. A person working with the best software systems for the latter must know principles of design and principles of theory of elasticity/strength of materials, respectively. Otherwise, the results would be disastrous.

There are two avenues of TRIZ training. One avenue is training in the university environment. Another avenue is training for industry personnel. This paper addresses the first topic.

TRIZ-training activities at WSU consist of two parts: special course on TRIZ and use of TRIZ techniques in the graduating “capstone” design course

Elective TRIZ Course

We developed (with the help from I. Vertkin) and offered for the first time in 1993 a four-credit (four contact hours a week) course on “Creative Problem Solving in Design and Manufacturing.” This elective (not mandatory) course is open to senior undergraduate students as well as to graduate students. The course gives basics of major TRIZ techniques which are taught in an interactive “hands on” way. The students solve exercise problem s in class, are given some problems as the homework, and also are given assignments involving solving more difficult problems which could be problems from the place of the students employment. All exercise problems are real life problems most of which were previously solved using TRIZ methodology and practically implemented.

Some assignments resulted in solving practical problems at the students’ companies in very cost-effective ways. Examples of such problems will be given in the presentation. There were several students who changed so much after taking the course that they became prolific inventors.

The first offering of the course attracted 8 students. Most of them liked the course which is very different from other courses in the curriculum. The latter are either highly analytical, or require learning of highly structured material with very little deviations allowed from the rigidly defined contents. On the contrary, the TRIZ course encourages original thinking, offers challenging problems, and provides with the powerful methodology allowing to solve these problems. Some students stated that this was “the best class in the curriculum.” As the result, enrollment in the course was growing continuously and reached 57 for the fifth offering (Summer, 1995). Majority of our students are part-timers working for large local manufacturing companies.

Use of TRIZ in “Capstone” Design Course

After the success of the TRIZ course, some basics of TRIZ were incorporated into the senior undergraduate “capstone” design course. Traditionally , this course had required students to design a device for a specified purpose and to participate in its fabrication. The resulted devices were usually very heavy and cumbersome, they required a very large effort, overloaded the machine shop, but usually did not significantly enhance design creativity of the students.

Now, the principal direction of the course is changed towards creative conceptual design. The teams of students are given basic design and manufacturing problems, which are approached using TRIZ methodology in order to develop conceptual solutions. Since the TRIZ course is an elective one and only about half of the students elected it, they were given four hours of lectures on the TRIZ methodology. After this, they are divided into teams, and each team is given a design element or a manufacturing process which has to be conceptually improved. With the help from the instructor, the TRIZ algorithms are applied to all these problems in class and novel conceptual solutions are developed. After this stage, the students are performing a patent and literature searches which help selecting the best concepts and, in some cases, give directions for their modification. Unfortunately, patent database is underutilized both in industry and, even more so, in the educational process. After selection of the best concept, students make preliminary and then final design drawings while paying special attention to issues of manufacturability. The next step is fabrication of a conceptual prototype and then testing of the most important parameters of the corresponding devices.

The new “capstone” design course was offered twice – in the Fall 95 and Winter 96 semesters. Both times there were very large enrollments for such a class, 34-35 students. Each time the class was split by the instructor based on a uniform distribution of GPA between the teams. Such an approach forces students to develop working relations with other students who may have totally different backgrounds.

In F95 term, the following projects have been developed:

  1. Two different conceptual approaches to design of briquetting roll press for bulk
    materials. Conventional presses have rolls with reciprocating half-molds. Such system,
    which is universally used in industry, requires expensive manufacturing and produces
    briquettes of less than desirable strength. Students were guided through TRIZ analysis of
    the problem and designed two much better modifications of briquetting presses. Small
    hand-driven prototypes were fabricated and tested. Two students continued the project
    during the next semester as a directed study. This work resulted in a system which is now
    being submitted to industry for implementation.
  2. Novel design of power transmission gears in which sliding and rolling in the mesh are
    physically separated. A hand-driven prototype was fabricated and tested.
  3. Novel design of power transmission key connection in which the key is flexible before
    insertion. Significant (5-6 times) reduction of maximum stresses in the connection was
    demonstrated. The fabricated prototype allows to compare four different key connections.
  4. Modification of gear train preventing development of gear rattling. Hand-driven
    prototype was tested in different regimes.
  5. Innovative orientation device for oblong parts (such as logs for paper mills). The
    prototype for pencils was fabricated and tested.
  6. Modification of powertrain for the previously designed and built hybrid electric car
    (for a national competition).

In W96 term the projects were:

  1. Accessories drive for internal combustion engines. Three teams designed, fabricated, and
    tested three different versions of variable transmission ratio flat belt drives. One
    design is the subject of a patent application by WSU.
  2. Clamping device with a wedge mechanism. Use of thin-layered rubber-metal laminates
    allowed to enhance efficiency of wedge mechanism while high -friction coating enhanced the
    clamping force even more. A compressed air – powered demonstration rig was designed and
    built. It compares conventional and the newly designed clamping devices.
  3. Bench vise to handle parts of arbitrary shape. Two versions, one with spring-loaded pins
    and another with vacuum activated bags filled with granular media, were fabricated and
    tested.
  4. Universal joint with “solid state” trunnion bearings which are based on
    thin-layered rubber-metal laminates, do not require lubrication, are not sensitive to
    contamination, and have better efficiency than conventional bearings. A manually driven
    demonstration rig was designed and fabricated.
  5. Frame for a human-powered vehicle (recumbent bicycle) for the National Student
    Competition. TRIZ principles were applied for designing the frame. Although WSU never
    before participated in such competitions, the team has won the fourth place and
    “Special Recognition” by the judges for the eport and the fourteenth place (out
    of 32 participants) in the overall competition.

These projects not only taught students how to approach problems and how to develop novel concepts. They also gave the teams a task and an opportunity to walk through the complete sequence of design actions (concept development, patent search, preliminary and final design, fabrication, testing). the students learned about topics which they never heard about before, such as briquetting, use of thin-layered rubber-metal laminates, gear rattling, etc. They were instructed to use the least amount of resources, especially in fabricating complex parts. These challenges led to very fast development of strong working relations within the teams. Student evaluation of their team colleagues contributes 15% of the total grade.

Conclusions

  • Training in TRIZ and introduction of TRIZ principles into capstone design course result
    in very positive changes of mentality of the participants.
  • It is important to make the TRIZ methodology available for masses of students (and
    engineers); they are becoming more open, more creative, more mentally flexible.

References

1. Altshuller, G., Creativity as an Exact Science, Gordon & Breach Science Publishing House, 1984, New York

2. Fey, V., Rivin, E., Vertkin, I., “Application of the Theory of Inventive Problem Solving to Design and Manufacturing Systems,” Annals of the CIRP, 1994, vol. 43/1, pp. 107-110.