Experiences of Teaching and Applying the Essence of TRIZ with Easier USIT Procedure
Toru Nakagawa (Osaka Gakuin University),
Proceedings of TRIZCON2002: Fourth Annual Altshuller Institute for TRIZ Studies International Conference held at St.Louis, Missouri, on April 28-30, 2002, pp. 
Discussions by Ed Sickafus (NTELLECK, USA) on Nov. 27, 2001 and Dec. 30, 2001. 
Slides prepared for the talk by Toru Nakagawa on April 21, 2002.
[Submitted to the Conference on Nov. 26, 2001 and revised on Jan. 19, 2002.] [Slides for the talk prepared on April 21, 2002]  [Posted here on May 16, 2002]
  [Posted in Japanese translation on Jan. 7, 2002.]
For going back to Japanese  pages, press  buttons.


Preface (Toru Nakagawa, May 15, 2002)

This paper was submitted for presentation and published in the Proceedings of TRIZCON2002, but was not orally presented in the conference because the author had to cancell the trip due to some urgent family situation.  The Altshuller Institute has kindly posted this paper and the slides in their Web site and has allowed me to repost them in this site.

The paper was submitted to the Conference on Nov. 26, 2001 in an almost final form.  It describes my expereinces of teaching and applying USIT in 3-day Training Seminars and the USIT methodology in detail.  With this work I myself was convinced much that USIT has adopted the essence of TRIZ and is an easy-to-learn and well-structured procedure for creative problem solving.

I sent the preprint to Dr. Ed Sickafus, the developer of USIT, and on the next day received his reply via email, saying:

Toru, great job.  I look forward to hearing your presentation.  I've inserted a few comments (mainly for our discussion) and a couple corrections.  All the best,   Ed    (Nov. 27, 2001)
The discussions are posted here as well in dark blue fonts, under his permission, for the sake of readers' better understanding.  Section 10.3 was added inDecember.  The paper and discussions were translated into Japanese and posted in the Japanese page of this site on January 7, 2002.

The slides were prepared for the talk a week before the conference, and are posted here in the original PowerPoint file.  Please click here for the slides.

Contents of the paper are as follows:

1.  Introduction
2.  TRIZ/USIT Background in Japan
3.  USIT 3-day Training Seminars
4.  Introduction of USIT
5.  Selecting the Problems to Solve
6.  Problem Definition Stage in USIT
7.  Problem Analysis with Closed-World Method
   7.1  Objects, Attributes, and Functions
   7.2  Constructing Closed-World Diagram
   7.3  Qualitative Change Graphs
   7.4  OAF Diagram
   7.5  Inplication of the Closed-World Method
8.  Problem Analysis with Particles Method
   8.1  Sketches of Present Situation and Ideal Situation
   8.2  Action-Property Diagram
9.  Space/Time Characteristics Analysis
10.  Solution Generation Methods
   10.1  Operations on Objects, Attributes, and Functions
   10.2  Combination and Generalization of Solutions
   10.3  Usage of Results of the Analyses in the Solution Generation Stage
11.  Application of Solution Generation Methods
12.  Usage of TRIZ/USIT in Industries
13.  Evaluation and Current Status of USIT in Japan
About the Author

I am very grateful to:
    The Altshuller Institute for TRIZ Studies (USA):  Web Site:
    Dr. Ed Sickafus, Ntelleck LLC. (USA):   Web site:

Top of this page Abstract 1. Introduction 2.  Background 3.  3-day Training Seminar 4. USIT Introduction 5. Selecting Problems 6. Problem Definition 7. Analysis (1) Closed-World Method
8. Analysis (2) Particles Method 9. Space/Time Characteristics 10. Solution Generation Methods 11. Application of Solution Generation 12. Usage of TRIZ/USIT 13. Evaluation and Current Status References Slides (PowerPoint) Japanese page




Experiences of conducting 3-day training seminars of USIT ("Unified Structured Inventive Thinking") in Japan are reported in detail.  Engineers from multiple companies participated the seminars and were trained with lectures and group practices of solving real brought-in problems by applying USIT step by step.  Current revised version of the USIT methodology itself is described in detail, as taught in the 3-day seminar.  Methods of teaching USIT, applying USIT, and introducing USIT in industries are also described together with the reactions of the participants.


In order to overcome the present difficulty in wider penetration of TRIZ ("Theory of Inventive Problem Solving") [1] into industries, the present author [2] argued the following points:

In the present paper, experiences of teaching USIT and applying USIT to real industrial problems are reported.  Experiences are described below along the course of the present author's 3-Day USIT Training Seminars, where USIT is taught from the beginning and is applied to real industrial problems brought in by the participants.


TRIZ has been introduced in Japan [4] for these five years in the forms of monthly journal articles, textbooks, Web sites (e.g., Nakagawa's "TRIZ Home Page in Japan" [5]), introductory/training seminars, software tools, etc., almost all in Japanese language.  Thus there are many pioneering engineers in (mostly big) industries who have been interested in and studying/practicing TRIZ.  Such industrial pioneers had chances of attending TRIZ seminars (of mostly one to three days) and have already mastered the usage of TRIZ software tools.  However, it has been very difficult for them to master the TRIZ way of thinking and to obtain the skill of applying TRIZ to their real problems.

USIT was developed by Ed Sickafus at Ford Motor Company in 1995 by adapting Israeli SIT, i.e. a simplified version of TRIZ.  He published an intensive textbook of USIT [3] and two conference papers on his activities [6, 7] but no compact paper on his methodology.  The present author attended at Sickafus' first out-of-Ford USIT Training Seminar for three days in March 1999 and started to introduce USIT into Japanese industries.

In 1999 Nakagawa posted three introductory articles on USIT [8-10] in his Web site, and soon started to conduct 3-Day USIT Training Seminars [11].  For these nearly three years, he has given many lectures on USIT to TRIZ users in Japan, posted a large number of USIT-related articles (especially [12]) in his Web site both in Japanese and in English, and presented three conference papers [2, 4, 13].  USIT 3-Day Training Seminars have been conducted six times so far, including 3 times under in-company situations [11] and 3 other times under multi-company situations [14].  Thus, most of the participants of his USIT Training Seminars had background of both TRIZ and USIT beforehand more or less.


The seminars reported here mainly were of multi-company type, organized by Mitsubishi Research Institute (MRI), and conducted by the present author as the Instructor.  The first seminar of this type was carried out in January 2000 as reported in detail in [14], and the second and third ones in July and September, 2001 in a similar but refined way.

From the beginning of sales of TRIZ software tools, MRI has been organizing users meetings and voluntary study groups of customer engineers regularly.  USIT has been introduced to them in short lectures and also in a one-day seminar.  On such a basis, MRI called for participation to the 3-Day Training Seminar.

Every participant is requested to bring in a problem to be solved in the seminar.  The problem should be real (or semi-real) but should not be confidential.  This type of request was adapted from Sickafus' seminar [8] with the intention to produce experiences of solving real problems with USIT and to enhance the motivation of the participants.

In order to encourage the participants to bring in real, worthy-to-solve problems, MRI announced beforehand a Confidentiality Agreement to be signed by all the parties involved [4, 14].  The Agreement says:

The policy in this Agreement is based on a well-known historical Japanese story of Ooka Echizen-no-Kami [14].  It was established as our solution to the "TRIZ Case-Study Contradiction":

"For beginners to learn TRIZ, good examples of successful cases are helpful.  But the better the application results are, the less chances to be published because of companies' secrecy policies.  Thus the beginners do not have chances to study good cases, and remain as beginners." [14]

The request of bringing in a problem under the above Confidentiality Agreement actually worked well in cooperative problem solving in the seminar, but some engineers felt difficulty in the following points:

The three seminars actually received 12, 9 and 8 participants for the capacity of 15.  Most of them were pioneers of TRIZ and USIT study in their companies, but a quater of them were rather novices.

Fig. 1  Time Schedule of the 3-Day USIT Training Seminar

The 3-day seminar was conducted for 24 hours in total with the time table as shown in Fig. 1.
In the opening of the seminar, the Instructor shows the target of the seminar as:

"To learn the spirit in TRIZ and to master the USIT procedure for creative problem-solving and innovation, through lectures and cooperative group practices of solving real brought-in problems."

The policy of the Confidentiality Agreement is explained again in the opening and is signed by all the participants including the Instructor and MRI members.


In the morning of the first day, general introduction is given on TRIZ and then on USIT, so as to learn or remind the basics of them and to get prepared for the succeeding group practices of solving real problems with USIT.

The lecture on TRIZ focuses on:

In the introduction of USIT, its historical background is first summarized with reference to Israeli SIT [15] and Sickafus' work at Ford [6, 7].  Then, main features of USIT are shown as:

The whole procedure of USIT for creative problem solving is presented in the flowchart in Fig. 2.  This is based on Sickafus' USIT textbook [3] but is revised by the present author in several points as the results of his experiences in Japan, as are mentioned later.

Fig. 2  Flowchart of the Whole USIT Procedure

The USIT procedure is explained by showing two full case studies [9, 10] and then step by step along the procedure together with some other examples, including [13, 16].  The four principal examples used in the Seminars are:


After lunch of the first day, all the participants are invited to introduce themselves and their brought-in problems one after another for about 5 minutes each.  The problems are submitted beforehand to the organizer in one-page free format of A4 size, containing brief explanation and some illustrative figure(s).  People are advised to explain not only the difficulty of the problem itself but also its significance, its rough mechanism, his/her technical background and career, etc.

Then we start the session for selecting the problems to solve together in the Seminar.  The Instructor explains the present situation as:

The number of problems to be solved is determined by the time available especially at the sequential presentation/discussion and by our capacity of understanding all the problems at the same time.  Less number of problems (i.e., 2 or 1) is not desirable because the participants cannot see different enough aspects and situations in applying USIT.

For selecting the problems, the Instructor advises the following criteria:

Then the Instructor asks the participants to raise their hands if he/she eagerly wants to tackle his/her own problem at the Seminar.  Some of the participants may not raise their hands, possibly because they are not personally involved in their brought-in problems or because they feel their problems too broad/vague.

Then we usually select the problems by voting.  Every participant is given two votes for the problems (other than his/her own) which he/she wants to join to solve.  This voting usually (i.e., in all the three cases of our experience) makes a reasonable result.  It is nice that not the Instructor but the whole participants have decided the problems to tackle in a fair and open manner.

Finally, participants are assigned to groups for selected problems, on the basis of their votes.  Proposers of the selected problems belong to the group of their own, of course.  Since other participants stated two choices in the voting, it is usually not difficult to make such practice groups.  It is desirable to form groups with members having different backgrounds and specialties.  Multiple participants from a company are advised to join different groups.

Now that the problems and group members are decided, we start the group practices of solving the problems by use of the USIT procedure in five sessions for two days and half.  Each session has the following three sub-sessions (as adopted from Sickafus' Seminar [8]):


In this stage, the proposer explains the problem again in more detail to the group members, and the group makes Q&A and discussions and finally writes down the following items in a concise manner:

In the lecture of this session, the Instructor emphasizes the following points:

In relation to the Plausible Root Causes, the following points are remarked:

This Problem Definition Stage appears to be simple and easy to conduct at first sight.  However, at the end of the Seminar, most of the participants say that this is the step found most crucial and hence difficult in the whole problem solving procedure.  Concise statements of problem definition and Plausible Root Causes clearly determine the direction of all the subsequent efforts for solving the problem.

The one-page problem statements submitted beforehand by the proposers have more detailed descriptions but often found unclear and less significant under the requirements in USIT.  The capability of the proposer to adapt the group discussion flexibly is found to be the key to fruitful/productive results in the seminar.

In a case conducted in [14], the problem proposal was "to find a method of discriminating micro-bubbles from small contaminants at the monitoring station in the loop of washing liquid for cleaning the wafers of micro-electronic devices".  The group found "the methods to eliminate or to avoid producing micro-bubbles" were more significant as the problem definition.  Even though the proposer was in charge of monitoring the washing liquid, he was flexible to shift the focus of the problem; thus his group succeeded in making meaningful and productive solutions as the results of the Seminar.

In another case conducted in [14], the proposer wanted to "find a method of breaking waste plastic cases of TV sets, vacuum cleaners, etc. in relatively larger pieces".  The waste plastic cases need to be broken at the site of collection for easier transportation to the processing site, where the plastic pieces are classified according to their materials after analysis.  The analyzer is large and not portable.  If the plastic cases are crushed in ordinary ways such as pressing, many small pieces are produced and decrease the efficiency of the analysis and classification.  Though the group members asked and suggested about possibilities of other processing orders, the proposer insisted that this processing order is his definite conclusion after a large number of trials.  So the group followed the proposal and made hard efforts for breaking plastics into larger pieces without producing smaller ones.

Just before lunch time of the third day, a group member came up with a simple idea of "putting all crushed  pieces from a wasted case into a separate bag."  Only a piece in a bag need to be analyzed for classifying the bag.  This idea was outside the problem definition but solved the problem quite efficiently.  This example shows the importance of considering the whole process (or the whole problem system) in more flexible eyes at the stage of Problem Definition.

[*2)  E. Sickafus, Nov. 27, 2001:  In the problem definition stage (before analysis) do you reduce a problem to its minimum number of objects?  Do you discuss points of contact and active attributes in order to force students to think about fundamental phenomena supporting the functions of the system? ]


In the morning of the second day we start the Problem Analysis Stage in USIT.  As shown in the flowchart in Fig. 2, USIT has three analysis methods:

In USIT either one or both of Closed-World Method and Particles Method may be used, depending on the nature of the problem.  In the present author's Training Seminar, these two methods are applied sequentially in this order to all the problems, for the purpose of understanding their effectiveness and contributions.  The Space/Time Characteristic Analysis should be carried out always.

At the beginning of the Problem Analysis Stage, we first introduce USIT's basic concepts of Objects, Attributes, and Functions, and then start to analyze with the Closed World Method.

7.1  Objects, Attributes, and Functions

Most important contribution of USIT to the problem solving methodology is its introduction of the basic concepts of Objects, Attributes, and Functions and its utilization of them in a unified way throughout the whole procedure.  They are defined as [3, 17]:

It is very instructive to show Sickafus' examples and anti-examples of these concepts [3, 17].

It is important to notice that these concepts are interrelated.  Sickafus shows the scheme:

"A Function interacts an Attribute of an Object with an Attribute of another (or the same) Object to modify (or else prevent from modifying) an Attribute of a third (or the same) Object".

His point is that among various Attributes of interacting Objects we may always select one most significant Attribute for each Object in the above scheme.  For instance, he expresses the bolt-nut Function as:

"The Angle of the Bolt interacts with the Pitch of the Nut to change the Position of the Bolt".*3)

[*3)  E. Sickafus, Nov. 27, 2001:  At a point of contact between two objects there can be multiple pairs of attributes support the same or different functions.  Insights are gained by identifying as many of these as seem cogent.]

Sickafus' definition of Objects, Attributes, and Functions is rather strict and may not be easy to follow at first for a learner, but later it becomes clear to understand and quite agreeable more and more.

"Information" is regarded as a kind of Object in USIT so as to explain wide variety of problems for detection, measurement, control, etc. in a simpler and consistent way (see, e.g., [9]).

7.2  Constructing Closed-World Diagram

In the Closed-World Method, we should first construct the Closed-World Diagram.  This is the USIT way of functional analysis for clarifying the functional relationships among the Minimal Set of Objects in the original design intention of the present system.

The Minimum Set of Objects are a set of Objects absolutely needed to contain the problem and are extracted from the Objects listed up in the Problem Definition Stage.  In the process of choosing the Minimal Set of Objects, the names of the Objects should be made generic in order to avoid Psychological Inertia by technical terms.  Note that this step has been moved in this paper from its original position in the Problem Definition Stage.*4)

[*4)  E. Sickafus, Nov. 27, 2001: This answers my question about minimal set of objects.]

Sickafus sets the following rules for constructing the Closed-World Diagram:

The "functionally beneficial" relationship of Object B toward Object A means simultaneously that:

These rules are rather strict and urge the analysts to draw quite simple diagrams showing the Objects and their principal (i.e. beneficial) Functions, for the purpose of revealing the intention of the original design of the present system.  Once such a simple diagram is drawn, it conveys much clearer message than ordinary functional-analysis diagrams which show a large number of arrows of less significant functions as well.

However, even though a number of examples of Closed-World Diagrams are shown in Sickafus' textbook [3], his Seminar Materials [17], and in my Web site [2, 9, 16], they are not sufficient yet for USIT learners to master this diagram.  In our USIT Seminars in Japan, we have been learning Sickafus' real intention little by little, through the experiences of various cases.

The present author sometimes felt temptations to additionally draw harmful/insufficient functions, subsidiary functions, points of problem, etc. in this diagram.*5)  But he now understands that the simple drawing structure should not be distorted or changed and that under such restriction it is not harmful to put some additional description when it helps to make the problem clearer.  Sickafus says that the Closed-World Diagram analyzes not the problem but the system as it was designed to function properly.*6)

[*5)  E. Sickafus, Nov. 27, 2001:  This is a common tendency for newcomers to USIT.  I think it arises from good technical training to do complete detailed analyses.  Whereas, USIT is about creating new viewpoints of a problem quickly.  USIT is intentionally designed to avoid the typical engineering analysis.  The reason is that the value of USIT is to offer new ways to look at a problem.  We already know how to do engineering.]

[*6)  E. Sickafus, Nov. 27, 2001:  I believe it is helpful to point out to students that the CW-diagram does not analyze the problem.  Instead, it analyses the system as it was designed to function properly.]

7.3  Qualitative Change Graphs

We next analyze the harmful/insufficient effects in the problem in terms of Attributes of Objects.  This analysis complements the preceding analysis with the Closed-World Diagram.

Fig. 3  Qualitative Change Graphs.  Picture Hanging Kit Problem [17]

The Qualitative Change Graphs are actually the two prefixed graphs, as illustrated in Fig. 3, in which we are requested to specify the ordinates and the abscissa as:

We should understand that these graphs are schematic just to show increasing/decreasing relations in multiple graphs without distinguishing their actual details.

The left graph simply says that if one of the Attributes in the list increases, then the harmful/insufficient effect of the problem increases.  Thus we may regard these Attributes as "problem-causing Attributes".  On the other hand, if any Attribute shown under the right graph increases, the harmful/insufficient effect will decrease.  Thus we may call such Attributes as "problem-preventing Attributes".*A2)

[*A2)  E. Sickafus, Dec. 30, 2001:  This is a bit confusing.  "Problem-causing attributes" are the inverse of "problem-preventing attributes".  They are not different attributes.]

The present explanation is simpler and more effective than the one in Sickafus' Seminar in 1999 [9].  Now, it is not necessary to list up as many Attributes as possible for all the Objects at the stage of Closed-World Diagram and to eliminate irrelevant Attributes in this stage of Qualitative Change Graphs.*7)

[*7) E. Sickafus, Nov. 27, 2001:  I would argue that all attributes identified in the palusible root-causes analysis belong in the QC-diagrams.  Furthermore, each attribute offers a point of focus for finding solution concepts.]

7.4  OAF Diagram

Next in the Closed-World Method, Sickafus uses Object-Attribute-Function (OAF) Statements and OAF Diagram in his textbook [3] and in the recent examples posted in his Web site [18].  They request explicit and consistent statements of all relevant Functions in terms of Attributes, in the form mentioned in Section 7.1.

Sickafus did not teach the OAF Diagram in his 3-day Seminar in 1999 [8] because of shortage in time.  The present author feels this method too complicated, and has decided not to teach/use it in Japan.*8) *9) *A3)

[*8)  E. Sickafus, Nov. 27, 2001:  Where I find the OAF diagram most useful is as an aid to understanding and identifying attributes.  Most students being introduced to USIT have little trouble understanding objects (except for “information”) and quickly learn to understand functions.  However, many have difficulty with attributes, especially when asked to use them as a point of focus in applying dimensionality as a solution technique.  That learning to identify and use attributes may be difficult should not be considered to be a drawback of the methodology.  It is not if the result of learning attributes strengthens one’s abilities as a problem solver.  OAF diagrams are a tool for this purpose.]

[*9)  T. Nakagawa, Dec. 28, 2001:  The present author feel that the participants of his USIT Seminars in Japan do not feel so much difficulty in understanding the concepts of attributes.  In the early stage of USIT lecture, the case study of "Detection of small water leakage from a gate valve" is usually presented.  In this case, various properties of water are shown in terms of Attributes, and they are intensively used in finding various solutions by use of the Attribute Dimensionality Method.  This may be a reason why Japanese USIT learners understand the use of the Attributes relatively smoothly.

In order to teach the OAF Diagram at the Training Seminar, it would take 1.5 to 2 hours additionally for lecturing and practicing at a level to make the OAF Diagrams in a somewhat consistent way.  Yet, the present author is afraid that the participants do not really feel themselves confident in their understanding of correct way of constructing the OAF Diagram and in its usefulness.  At the present situation, without the OAF Diagram, we do not feel such needs of it.  The present author believe that it is a nice policy for us to keep USIT concisely at the level where its whole theory and practices can be learned in three days at the Training Seminar and the seminar participants can be convinced of the usefulness of every step of the USIT procedure.  So the present author would choose not to teach OAF Diagrams at his USIT courses. ]

[*A3)  E. Sickafus, Dec. 30, 2001:  I don't use OAF diagrams unless needed.  I pay attention to students comments and questions in class to try and detect any uncertainity on their part regarding the meaning of attributes.  If I find students confusing attributes and metrics, as an example, this is an indicator to me that they may benefit from OAF diagrams.  The most obvious difficulties surface when teams begin to report their solution concepts to real-world problems they solve in class.  The instructor quickly becomes aware of any imbalance between the metaphorical strength of objects, attributes, and functions in leading a team to new solution concepts.  Such imbalance, when it exists, is a clue to areas that may need new emphasis by the instructor. ]

7.5  Implication of the Closed-World Method

Real significance of the Closed-World Method can best be understood in reference to Roni Horowitz' papers and ASIT [15, 19].

Roni Horowitz and Oded Maimon [15] demonstrated by experiments that engineering people agree to regard a solution as "inventive" if it satisfies the following two conditions:

The Closed-World Restriction may be understood as a form of TRIZ' concepts of minimal introduction of Resources and of Ideality.

The Qualitative Change Requirement can be explained in the following way:

When we learn a problem causing relationship as shown in the left graph, we would immediately think of a method, i.e.

This will results in an ordinary engineering solution (in case of easy problems) or in some situation in Technical Contradiction (in case of difficult problems).

"Inventive solutions", on the other hand, are the cases where any of the following three types of Qualitative Change is achieved:

It should be remarked that these three ways of thinking are more straightforward than the TRIZ way of thinking, i.e. constructing the Technical Contradictions and then searching for possible ways to solve them.

ASIT ("Advanced Structured Inventive Thinking") [15] has the policy to concentrate their problem-solving efforts to the search for "Inventive solutions" satisfying the above-mentioned two conditions.  This may be a "purified" TRIZ approach.  Examples of such solutions may be found in the Web site of Horowitz [20].

However, USIT's approach is different from ASIT.  Sickafus wrote in [7] that he decided to put stress not on the search for "Inventive solutions" but on quickly obtaining multiple creative solutions to real industrial problems.  He has chosen this policy in order to maximize the merit of creative problem solving in real industrial situations like at Ford.

Thus, in USIT, even while we understand the ASIT approach, we rather use the Closed-World Diagram as a method of functional analysis, and the Qualitative Change Graphs as a method for analyzing the problem-causing and problem-preventing Attributes.  These diagram/graphs are referred later in the Solution Generation Stage (See Section 11).*10)

[*10)  E. Sickafus, Nov. 27, 2001:  A philosophical note:  TRIZ emphasizes the identification of contradiction among pairs of effects.  This is often a troublesome step for students.  Once a contradiction is found, the next step is to separate its parts.  USIT takes the approach of ignoring contradictions and identifying all plausible root causes.  Each is treated individually.  This procedure leaps over the TRIZ step of finding contradictions. ]


Particles Method was adopted from Altshuller's Smart Little People's Modeling [1] but was extended and refined much by Sickafus [3].  This method is the approach to think of an image of the "Ideal Solution" first and hence is applicable even to the cases where we do not have any  present system yet.

As application examples of this Particles Method, the present author has always used, in his USIT Training Seminars [11, 14] as well as in his papers [2, 4, 12], the case of "Increase the Foam Ratio in Forming a Porous Polymer Sheet" [10].  The case was made at Sickafus' Training Seminar [8] as a trainee.  This one example has been very useful in teaching the Particles Method.  Almost all trainees in the 3-Day Training Seminars applied the method well to their problems and found it easy and powerful.  (Please refer the figures of this case in previous publications mentioned above.)

8.1  Sketches of Present Situation and Ideal Situation

First we draw a sketch of the present situation to clarify the mechanism of the harmful/ insufficient effect of the problem.  This is often a close-up view of the sketch we drew in the Problem Definition Stage, and corresponds to the view in the Operational Space in TRIZ.

Then we are requested to draw a sketch of the Ideal Situation.  We should draw the situation itself without thinking/drawing any means to achieve it.  This request often sounds very difficult at first and gives us a shock to change ourselves in our thinking ways.  Then we somehow squeeze out a sketch of an ideal situation, even though it appears absurd at first.  Inserting a few key words in the sketch is helpful to clarify the situation.

And then we are requested to compare the two sketches and put small "x marks" at the places wherever we see any difference.  We should not restrict ourselves in choosing these places on the basis of our guess of solutions.

These "x marks" are now called the "Particles".  Particles are supposed to be magical substances/Fields which can perform any desirable actions and can have any desirable properties.  Then, we are asked what sort of actions we want them to perform and what sort of properties we want them to have.

8.2  Action-Property Diagram

We now write the action we want the Particles to perform in one sentence.  This is easily done by taking the keywords in our sketch of Ideal Situation and by converting them into a sentence.  Since the sentence often includes a few action keywords combined with "and", such actions are then described separately at the second level with explicit indication of the AND relationships.  Then each action should be broken down further into possible elements of actions and drawn in a form of the AND/OR Tree known in logic.*11)

[*11)  E. Sickafus, Nov. 27, 2001:  Maybe we are saying the same things, but I put a little different emphasis on the process.  I start by having the students write a statement of the ideal solution as a compound sentence without concern for the particles.  Then the sentence, in the next lower level, is divided into its and/or clauses.  In the next lower level the student now considers what the particles are doing to accomplish the actions of the particles.  Under actions are listed multiple properties that support the actions. ]

The Instructor advises as follows:

Next we should list up possible desirable properties for performing these actions.  The guide lines are:

In the Training Seminars, the groups are very often excited in this session to find themselves coming up with a variety of new ideas in combination of actions and properties.


At the final step in the Problem Analysis Stage in USIT, the problem is analyzed to clarify its Space and Time Characteristics (or "Uniqueness" in Sickafus' preferring term [3]).

The Space Characteristic Analysis usually draw a graph in the following way:

The Time Characteristics Analysis is also done in a similar way by drawing a graph with some suitably-chosen time axis.

Examples of these graphs can be seen in [9, 10, 12, 16].  The choice of characteristic spatial/temporal axes is the key to the expressive power of these graphs.  In the case of the "Micro-bubbles in washing liquid" problem, the looped route of the circulating washing liquid was chosen as the spatial 'axis', and the whole process cycle of washing the wafers was taken as the temporal 'axis'.

This analysis method can be used flexibly.  Sometimes drawings of system's structure itself (see [16]) and block diagrams of a complicated system serve to show their spatial characteristics.

Doing the process analysis at this step should have a wide application area.  For example, in the case of the problem of "Breaking waste plastic cases", mentioned in Section 6, we should have done the process analysis in more detail in this step.

Once such spatial/temporal axes chosen properly, the graphs suggest important viewpoints for understanding the unique nature of the problem, and further give hints of interesting ideas similar to those obtainable with the Separation Principle in TRIZ.

Originally, Sickafus [3] placed this method as a connecting link in between the Problem Analysis and Solution Generation Stages, because this method, though an analysis in nature, often stimulates solution ideas.  The present author, however, places this method at the final step in the Problem Analysis Stage [8], as shown in the flowchart in Fig. 2.  It is clear that this analysis should be done only once before the repeating processes in the Solution Generation Stage.*12)

[*12)  E. Sickafus, Nov. 27, 2001:  I introduce Uniqueness at the end of analysis and the beginning of solution techniques but emphasize it as a solution technique, as you know.  My reasoning is that the graphic display of desired functions as rectangles in space/time lead immediately and intuitively to solution by separation, overlapping, reversing, division, multiplexing, and demultiplexing. This makes the subsequent solution techniques much more easily understood. ]


We now start the third stage in USIT, i.e. Solution Generation Stage.  As shown in the flowchart in Fig. 2, we use five Solution Generation Methods (or Operators) repeatedly to generate multiple conceptual solutions.

The five methods are grouped into two categories:  Three methods are to be applied on Objects, Attributes, and Functions, respectively, whereas the other two methods are to be applied on Concepts (or Solutions).

10.1  Operations on Objects, Attributes, and Functions

Corresponding to the basic concepts of "Objects, Attributes, and Functions" for representing any technical system, USIT provides three Solution Generation Methods:

Note that Sickafus [3, 18] calls these simply as Pluralization, Dimensionality, and Distribution.

The Object Pluralization Method is applied to (or operated on) every Object in the system (especially those in the Minimal Set of Objects) so as to "Pluralize" it.  This operation has the following aspects:

The Attribute Dimensionality Method is applied to (or operated on) various Attributes of every Object in the system so as to modify the "Dimensionality" of the Object.  This operation contains the following aspects:

The Function Distribution Method is applied to (or operated on) all the Functions in the system so as to "Distribute" (or re-arrange) the functions among the Objects in the system (including newly introduced Objects).  The guidelines are:

Examples of application of these three Solution Generation Methods can be seen in Sickafus' textbook [3], his recent application example [18], and in Nakagawa's articles [9, 16].  Examples by Horowitz [21] in the ASIT method are also helpful.

Readers familiar with TRIZ [1] may understand that various methods in 40 Principles of Invention can be shuffled into the above three Solution Generation Methods and that the knowledge of Trends of Evolution may be actively used in these methods.  Thus these USIT methods are not a small selection of TRIZ (or any other) methods but rather a full set of TRIZ methods expressed in a way simple and easy to apply.

It has been traditional [1, 3] to show solutions as the result of application of either one of the solution-generation methods.  However, such solutions can be viewed in multiple ways as results of different USIT Solution Generation Methods.  Three methods in USIT focus their operations on either one of the three aspects (i.e., Objects, Attributes, and Functions), yet they usually generate some side effects on other aspects, as you see in the description of the methods.  This is inevitable because none of the three aspects can exist by itself.  Thus, we should understand that any solution can be regarded in multiple ways as the application results of different USIT Solution Generation Methods [16].

Figure 4 demonstrates such a solution in case of "Picture Hanging Kit Problem" [16].  As a solution for preventing a picture frame from tilting, the nail on the wall is made partly rough and partly smooth on its surface [3].  The hanging string should be adjusted at the smooth surface of the nail and then set at the rough surface.

Fig. 4.  A nail with smooth and rough surfaces (by Ed Sickafus [3])

This single solution can be viewed in the following four ways simultaneously [16]:

This understanding of solutions in multiple ways made the present author much easier to teach and apply these Solution Generation Methods.

10.2  Combination and Generalization of Solutions

The last two Solution Generation Methods are different from the former three at the point that they operate not on the elements of the system but on the solutions.

The (Solution) Combination Method is applied to multiple solutions (or solution elements) and combines them in various ways in space, in time, in parts, etc. to form a new solution.

Originally in USIT, Sickafus [3] defines a method named "Transduction".  It forms a sequential link between two Functions with a common Attribute of an Object as the bridge.  This means the two Functions are performed in coordination simultaneously, in sequence in space or in time, etc.  The present (Solution) Combination Method [16] is an extension of Sickafus' Transduction and covers much wider area of solution generation methods.

The (Solution) Combination Method has the following guide lines:

It is clear that the (Solution) Combination Method naturally contains a wide range of solution methods, such as those included in 40 Principles of Invention.  Especially, the Separation Principle in TRIZ [1] may be regarded essentially the same, but expressed in the opposite way, with the (Solution) Combination Method.  Whereas the Separation Principle says "to separate a contradiction, and then to combine", the present method simply says "to combine" in a way much easier to understand.  Thus, even though some of the solutions generated with the Combination Method may also be interpreted as the results of other three Solution Generation Methods (just as shown in Fig. 4), this method has a unique and important position in the whole theory of USIT, as shown in Fig. 2.

The (Solution) Generalization Method encourages to replace technical, specific terms in each solution with plain, generic terms [3].  This makes the solutions into concepts or metaphores, and make our scope broader.

The significance of the (Solution) Generification Method can best be understood in relation to the process similar to the Mind Mapping [22].  With this method, a concrete idea can associatively stimulate various related ideas in the scheme shown in Fig. 5.  This scheme is also important because it helps us systematize our solutions at the same time (see e.g. [23]).

Fig. 5  Scheme with Solution Generalization

10.3  Usage of Results of the Analyses in the Solution Generation Stage

It should be worthwhile to summarize how the results of the Problem Analysis Stage serve in this Solution Generation Stage.  First, in applying each Solution Generation Method, the following information obtained in the analyses are most useful:

When we search for various solutions, we are always thinking how to overcome the difficulties expressed in the Plausible Root Causes and, in more concretely, how to eliminate the problem effects which may be worsened with the problem-causing Attributes and reduced with the problem-preventing Attributes.  Thus, we may relate all our efforts and results during the Solution Generation Stage to these problem-causing/preventing Attributes which are listed in the Qualitative Change Graphs.  Associative or developmental relations among solutions and problem-causing/preventing Attributes are demonstrated in Fig. 6 for the case of "Picture Hanging Kit Problem" [16].  Even though this figure was made much later than the actual problem solving by Sickafus [3], understanding of this kind of structure will be helpful for us in our search process.

Fig. 6.  Relations among solutions and problem-causing/preventing attributes

(Solution) Generalization Method is the key method to make our solution search broader and more systematic in the scope.  The Ideal Situation (imagined in the Particles Method) and the Action-Property Diagram (obtained by breaking it down) serves as a model of hierachical system for our solutions.  With the (Solution) Generalization Method, we may draw our solutions in a new hierarchical system or rather draw them as additions and modifications in the Action-Property Diagrams.


In the present author's 3-Day USIT Training Seminars, a lecture on the Solution Generation Stage is given at the end of the second day, with two-folded intention:

It was rather difficult for the present author and for Japanese learners to understand how to apply the Solution Generation Methods.  It was a constant requirement from the seminar participants to explain the methods more clearly.  The present author learned the methods little by little with reference to various articles in TRIZ/USIT/ASIT and with experiences at the seminars, and has just reached the understanding explained in Section 10.

On the third day we have two group-practice sessions for the Solution Generation Stage in USIT.  The Instructor advises as follows at the beginning of the morning session:

  • First, on the basis of the Particles Method and the Space/Time Characteristic Analysis, try to find solution concepts rather freely.
  • Then, with reference to the results of the Closed-World Method, try to apply (especially the first three) Solution Generation Methods intently on every member of Objects, Attributes, and Functions.

  • During the analysis stage with the Particles Method (i.e., on the second-day afternoon), almost all groups have found that they are stimulated to come up with various elements of solution ideas and that the Action-Property Diagram is close to a hierarchical representation of possible solutions.  Thus it is natural for us to start the Solution Generation Stage somewhat in an informal manner on the basis of the results of the Particles Methods.  Solution ideas are recorded on the whiteboard with a lot of rough sketches, while the Action-Property Diagram are often enhanced in parallel with these new ideas.

    In 1 to 1.5 hours, most groups come up to the point of having exhausted most of simple ideas in their mind.  Thus they start to use the Solution Generation Methods one by one.  They often feel difficulty in this application, as mentioned above, but have succeeded in obtaining new ideas gradually.  Then during the group-presentation sub-session, they learn a number of more application cases achieved by other groups and are encouraged through the discussions.

    At the beginning of the afternoon session, the Instructor advises in the following way:

    The groups actually have come with slightly different paces; some groups made much advance while others experienced difficulties.  Nonetheless, all groups succeeded in obtaining several to twenty solution ideas to their brought-in real problems.


    After finishing the group practices of the whole procedure of USIT, the Instructor gives the last lecture on the usage of TRIZ and USIT in industries.  The points are:


    In the final discussion session and in the inquiry sheets at the end of the Training Seminars, the seminar participants have evaluated the USIT method in the following way:

    For the models of using USIT and TRIZ software tools (especially TRIZ knowledge bases) in a cooperative/complementary way, the following three alternatives are proposed [2]:

    Two case studies worked out in the 3-Day USIT Training Seminars were reported at MRI's users' study-group meetings by the seminar participants and were posted in the Web site "TRIZ Home Page in Japan" in Japanese [24, 25].  In order to record the cases smoothly and to encourage the participants to publish their case studies, a template for the Seminar Case Report was handed to them recently.

    The present author is the only instructor of USIT in Japan at moment.  But as the result of seminars and Web publications, USIT has become known pretty well among the TRIZ community in Japan.

    Some of the participants of the 3-Day USIT Training Seminars have been working actively in their companies to introduce and apply USIT (in addition to TRIZ software tools).  For instance, TRIZ/USIT activities by Yuuji Mihara at Fuji Photo Film Ltd. was reported by himself in "TRIZ Home Page in Japan" in Japanese [26], and one of his application result was reported in "Nikkei Mechanical" Journal [27].  In his company, two-membered TRIZ/USIT team is working to train their engineers in TRIZ/USIT and to do in-company consulting of several USIT projects in parallel.


    As the results of experiences of 3-day training seminars in Japan, an effective method of teaching and applying USIT (Unified Structured Inventive Thinking) has been established.  It is found that USIT has well adopted the essence of TRIZ and rebuilt it into a unified and structured procedure composed of problem-definition, problem-analysis, and solution-generation stages.  USIT has been found easy to learn and effective and powerful to apply for solving industrial problems creatively.


    The present author is grateful to Dr. Ed Sickafus for his continuous encouragement and his valuable discussions.*13)

    [*13)  E. Sickafus, Nov. 27, 2001:  And I am grateful to you for your efforts to bring USIT to the Japanese technical community. ]


    [1] See for example, Yuri Salamatov "TRIZ: The Right Solution at The Right Time", Insytec, 1999 (E); Nikkei BP, 2000 (J).
    [2] Toru Nakagawa, 'Learning and Applying the Essence of TRIZ with Easier USIT Procedure', ETRIA World Conference: TRIZ Future 2001, Nov. 7-9, 2001, Bath, UK, pp. 151-164; TRIZ HP Japan, Nov. 2001 (E), Aug. 2001 (J).
    [3] Ed. N. Sickafus, "Unified Structured Inventive Thinking: How to Invent", NTELLECK, Grosse Ile, MI, USA, 1997, 488p.
    [4] Toru Nakagawa , 'Approaches to Application of TRIZ in Japan', TRIZCON2000: The Second Annual AI TRIZ Conference, Apr. 30 - May 2, 2000, Nashua, NH, USA, pp. 21-35. ; TRIZ HP Japan, May 2000 (E), February 2001 (J).
    [5] "TRIZ Home Page in Japan", WWW site edited by Toru Nakagawa.  URL: http://www. (in English), php/nakagawa/TRIZ/ (in Japanese).  (Note: These are abbreviated here as "TRIZ HP Japan".)
    [6] Ed Sickafus, 'Injecting Creative Thinking into Product Flow', First TRIZ International Conference, Nov. 1998, Industry Hills, CA, USA; TRIZ HP Japan, Jan. 1999 (J).
    [7] Ed Sickafus, 'A Rationale for Adopting SIT into a Corporate Training Program', TRIZCON99: First Symp. on TRIZ Methodology & Application, March 1999, Novi, MI, USA; TRIZ HP Japan, May 1999 (J).
    [8] Toru Nakagawa, 'USIT Training Seminar (Mar. 10-12, 1999, Detroit) (Instructor: Dr. Ed Sickafus) Participation Report', TRIZ HP Japan, Mar. 1999 (J & E).
    [9] Toru Nakagawa, 'USIT Case Study (1) Detection of Small Water Leakage from a Gate Valve', TRIZ HP Japan, Jul. 1999 (J), Aug. 1999 (E)
    [10] Toru Nakagawa, 'USIT Case Study (2) Increase the Foam Ratio in Forming a Porous Sheet from Gas-Solved Molten Polymer', TRIZ HP Japan, Jul. 1999 (J), Aug. 1999 (E)
    [11] Toru Nakagawa, 'USIT Training Seminar in Japan: First Trial in a Company', TRIZ HP Japan, Sept. 1999 (J & E).
    [12] Toru Nakagawa, "USIT - Creative Problem Solving Procedure with Simplified TRIZ", Journal of Japan Society for Design Engineering, Vol. 35, No. 4, 2000, pp. 111-118. (J); TRIZ HP Japan, Apr. 2000 (E).
    [13] Toru Nakagawa, 'Staircase Design of High-rise Buildings Preparing against Fire - TRIZ/USIT Case Study -', TRIZCON2001: The 3rd Annual AI TRIZ Conference, Mar. 25-27, 2001, Woodland Hills, CA, USA; TRIZ HP Japan, Apr. 2001 (E & J).
    [14] Toru Nakagawa, 'USIT Training Seminar in Japan: (2) 3-day Seminar with Multi-company Engineers', TRIZ HP Japan, Feb. 2000 (J), Mar. 2000 (E)
    [15] Roni Horowitz and Oded Maimon: 'Creative Design Methodology and the SIT Method', 1997 ASME Design Engineering Technical Conference, Sept. 14-17, 1997, Sacramento, CA, USA; TRIZ HP Japan, Mar. 2000 (J).
    [16] Toru Nakagawa and Ed Sickafus, 'Commentary on "The Picture Hanging Kit Problem"', TRIZ HP Japan, Aug. 2001 (J & E).
    [17] Ed Sickafus, "USIT Training Seminar" Course Material, Mar. 1999 (E).
    [18] Ed Sickafus, 'The Sicillian Dolly', NTELLECK, LLC Web site:, Jun. 2001 (E).
    [19] Roni Horowitz, 'From TRIZ to ASIT in 4 Steps', TRIZ Journal, Aug. 2001 (E); TRIZ HP Japan, Sept. 2001 (J).
    [20] Web site:
    [21] Roni Horowitz, 'ASIT's Five Thinking Tools with Examples', TRIZ Journal, Sept. 2001 (E).
    [22] James Kowalick, 'Problem-Solving Systems: What's Next after TRIZ? (With an Introduction to Psychological Inertia and Other Barriers to Creativity)', First TRIZ International Conference, Nov. 17-19, 1998, Industry Hills, CA, USA (E); TRIZ HP Japan, Jan. 1999 (J).
    [23] Michael Lynch, Benjamin Saltsman, and Colin Young, 'Windshield/Backlight Molding - Squeak and "Buzz" Project - TRIZ Case Study', American Supplier Institute Total Product Development Symposium, Nov. 5, 1997, Dearborn, MI, USA; TRIZ Journal, Dec. 1997 (E); .TRIZ HP Japan, Sept. 1999 (J).
    [24] Hiroki Ueno, 'Case Study Report at the USIT Training Seminar: Effective Methods for Natural Air-Cooling of Electronic Devices', MRI Study Group Meeting, Jan. 2001 (J); TRIZ HP Japan, Jul. 2001 (J).
    [25] Yuuji Mihara, 'Case Study Report at the USIT Training Seminar: MRI Study Group Meeting, Nov. 2000 (J)
    [26] Yuuji Mihara, 'Experiences of Introducing TRIZ/USIT in Fuji Photo Film', TRIZ HP Japan, Nov. 2001 (J).
    [27] Tsukasa Sinohara, 'Fuji Film: Improving the Filter for Extracting Plasma from Blood', Nikkei Mechanical, Nov. 2001, pp. 72-73 (J)

    Note 1)  (E): written in English, and (J): written in Japanese.

    About the Author

    Toru Nakagawa is currently Professor of Informatics at Osaka Gakuin University.  Since he was first exposed to TRIZ in May 1997, he endeavored to introduce it into Fujitsu Labs for which he was working.  After moving to the University in April 1998, he has been working for introducing TRIZ into Japanese industries and academia.  In November 1998 he founded the public WWW site "TRIZ Home Page in Japan" and serves as the Editor.  He is currently working to introduce USIT as an easier TRIZ procedure.

    He graduated the University of Tokyo in chemistry in 1963, studied at its doctoral course (receiving D. Sc. degree in 1969), became Assistant in Department of Chemistry, the University of Tokyo in 1967; he did research in physical chemistry, particularly experiments and analyses in the field of high-resolution molecular spectroscopy.  He joined Fujitsu Limited in 1980 as a researcher in information science at IIAS-SIS and worked for quality improvement of software development.  Later he served as a managing staff in IIAS-SIS and then in R&D Planning and Coordination Office in Fujitsu Labs.


    Top of this page Abstract 1. Introduction 2.  Background 3.  3-day Training Seminar 4. USIT Introduction 5. Selecting Problems 6. Problem Definition 7. Analysis (1) Closed-World Method
    8. Analysis (2) Particles Method 9. Space/Time Characteristics 10. Solution Generation Methods 11. Application of Solution Generation 12. Usage of TRIZ/USIT 13. Evaluation and Current Status References Slides (PowerPoint) Japanese page

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    Last updated on May 16, 2002.     Access point:  Editor: