|TRIZCON2001 Paper: TRIZ/USIT Case Study||
Design of High-rise Buildings Preparing against Fire
- TRIZ/USIT Case Study -
(Osaka Gakuin University)
TRIZCON2001: Third Annual Altshuller Institute for TRIZ Studies International Conference held at Woodland Hills, California, on March 25-27, 2001 [Proceedings: 5-1 to 5-18]
[Posted here on Apr. 4, 2001]
|The original form of this work was posted in this WWW site in Japanese on Aug. 24, 2000 and then in English translation on Feb. 28, 2001|
This paper was presented last week at the TRIZCON2001 held by The Altshuller Institute for TRIZ Studies. For Japanese readers, the paper is translated into Japanese and posted separately in this Web site. My personal report of the Conference is also posted in Japanese today. The present author is grateful to The Altshuller Institute for TRIZ Studies for organizing the Conference with a great success and for permitting us to publish the Conference papers for wider circulation with authors' disposal.
The present work was originally posted in Japanese on August 24, 2000 in this WWW site, and then in English translation on February 28, 2001 in this site (and further posted in April Issue of the TRIZ Journal). The work was refined into this TRIZCON paper for an academic presentation, while keeping the original records of the thinking process. Recent information (i.e. after August 2000 and untill January 15, 2001) is written in Section 10 of this paper.
This paper records and illustrates my actual thinking process in one case of problem solving, by using TRIZ/USIT in a free manner in my mind. I hope this will be of some help for readers to understand a way of thinking with the spirits of TRIZ/USIT. (Please also see the Editor's Note at the end of this page.)
added on Apr. 25, 2001: Personal
Report of TRIZCON2001 by Nakagawa has been translated into English
|1. Introduction||2. The beginning||3. Problem definition||4. Analysis of conventional means||5. Tasks to be solved||6. Solving contradictions||7. Constructing solutions|
|8. Uncompleted sections||9. What to do in future||10. Recent information||11. Conclusion||Editor's Note||Original Posting. Feb. 28, 2001|| TRIZCON2001
Design of High-rise Buildings Preparing against Fire
- TRIZ/USIT Case Study -
By Toru Nakagawa
Osaka Gakuin University
The present paper reports a real case of having obtained an idea and having written it down as an invention on a topic from every-day life. On reading a TRIZ exercise problem requesting to improve a device for emergency escaping from burning high-rise buildings, the present author looked the problem differently and thought it more important to use staircases in fire emergency by preventing the chimney effects. He came out with a simple idea: "to open windows of the staircases in case of fire". A week later, he wrote down the solution in a format of preliminary patent application. The work was done without following any formal process, but the present author was well aware that he was guided by TRIZ and USIT. Problem definition was implicitly yet well guided by USIT, while the problem analysis and its solution were by the TRIZ method of deriving the technical and then physical contradictions to be solved by the separation principle. This gives us a lesson that the real essence of TRIZ can well be applied in a free and informal way in practice.
Introduction of TRIZ, i.e. the "Theory of Inventive Problem Solving", into industrial practices is still in its infancy stage in Japan and other countries . The penetration of TRIZ is taking time not because TRIZ is poor but rather because it is so rich. TRIZ has a huge body of methodologies and knowledge bases useful for creative development of technologies . Russian TRIZ experts have gained their skills for using TRIZ only through many years of hard training.
How to teach/learn/apply TRIZ in its essence in much simpler and effective way is the main issue for current promotion/studying/practice of TRIZ .
"What is the real essence of TRIZ?" is the most basic question. The important principles and methods of TRIZ, such as "40 Principles of Invention", "76 Standard Inventive Solutions", "Trends of Technical System Evolution", "Altshuller's Contradiction Matrix", "ARIZ (Algorithm of Inventive Problem Solving)", etc., are all too huge to be regarded as the core essence. The present author, as an independent learner of TRIZ, has gradually become understood of the core essence especially through his work of translating Salamatov's TRIZ textbook  from English to Japanese . His temporary understanding is that the concepts of evolution of technical systems, ideality, contradictions, and resources are the core concepts in TRIZ, and the dialectic way of thinking (which treats and solves problems as systems in evolution and in contradiction) is the essence in problem solving.
A simplified TRIZ process for creative problem solving was developed in Israel in 1980s  and then improved by Ed Sickafus at Ford Motor Company in the form of USIT, i.e. "Unified Structured Inventive Thinking" . USIT is a process having three stages: Problem Definition, Problem Analysis, and Conceptual Solution Generation. USIT does not use any knowledge base of TRIZ but is well based on the essential way of thinking in TRIZ, in the sense as mentioned above. The present author has been trying to introduce USIT into Japanese industries .
Case-study reports of applying TRIZ to real problems have been much demanded but rarely published due to companies' secrecy policies. The present author named the current situation as "TRIZ Case-Study Contradiction" in .
Under these situations, the present paper reports a real case of having obtained an idea and having written it down as an invention on a topic from every-day life. This work was done on August 1st and 7th, 2000 and its thinking process was recorded on August 15 and 23-24, 2000 and publicly posted in Japanese  on August 24, 2000 in the Web site "TRIZ Home Page in Japan" . The original posting has four parts: (1) Preface, (2) The beginning and background of the present idea, (3) Description of an invention, and (4) The thinking process and the influences of TRIZ/USIT. The present paper is slightly edited from the original posting  into an academic presentation, but reserves the original record of the thinking process.
The present idea was small and naive: "In order to keep staircases as emergency escaping route in case of fire, we should just prevent the chimney effects by opening the windows of the staircases widely". But once it was written down fully in the format of a patent application, the idea became big and strong as a new concept in building design. The whole process of idea formation and drafting was carried out intuitively and informally; but the present author was well aware of his using basic concepts of TRIZ and USIT in his mind. Problem definition was implicitly yet well guided by USIT, while the problem analysis and its solution were by the TRIZ method of deriving the technical and then physical contradictions to be solved by the separation principle. The present paper aims to show an actual case of creative problem solving carried out in a way informal and intuitive yet really based on TRIZ/USIT in its essence.
2. The Beginning and the Idea Formation of the Present Problem
2.1 Salamatov's exercise problem
On August 1st, 2000, I was working for translating Yuri Salamatov's well-accepted TRIZ textbook, i.e., "TRIZ: The Right Solution at the Right Time" , from English into Japanese. We were at the stage of revising our third draft by closely checking against the English text. I came up to Problem 43. The problem is quoted here in its full text with minor revisions reflecting our Q&A with the Editor of the English Edition :
A 'rescue hose' was invented. It was made of elastic cloth and armoured with glass fiber. When the hose is not used, its diameter is a bit smaller than the average thickness of man. One can regulate fall speed by expanding one's elbows and moving one's knees together. Unfortunately, not everyone can use this bright idea. The system cannot be recommended to elderly people and children even after long training.
The system was improved by G. Vilchinsky (Soviet Patent no. 1 024 098).
[When a person gets on,] Elastic chambers (1) shrink, driving excessive pressure through the pipe line (2) into the reservoir (3). The piston (4) moves, compressing the spring (5). When a person exits the receiving chamber (6), the spring brings the piston to its initial position, air enters the crushed chambers (1) expanding them.
We suggest that you improve it further: the process of technical system development is endless. What is bad about the system? Try to make it more effective, decrease it in size and mass, add new functions to it, for the fire may not happen at all the system will be out of use.
But the device for urgent evacuation, especially the one illustrated in the above figure, does not seem to work effectively, even reading the explanation many times. "Something is wrong in this idea", I have had such a vague impression for over a year since I read it first.
2.2 Coming up with the initial idea
Reading the description and the figure of the Vilchinsky's device again and again on August 1st, I did not become understood its mechanism and I thought this device would not work well. This was the initial point of the present work.
I also remember the emergency device "Slow-Down" equipped at the window near the elevator hall of my university office, which is located on the 4th floor of an 8-storied building. In case of emergency, we are supposed to put its belt around our waist and go down by hanging on the rope. I used to read its instruction written on the box several times, but have had no experience of using it. Except for the emergency cases, no one should handle it; thus no one in the building has made a practice with it yet. In case of a real fire, and having no other ways, we will have to use it in a 'do-or-die' situation.
So I thought I should go back to reconsider the availability of ordinary facilities: "Elevators should not be used because of their risks of having the operation stopped and of our being confined inside. Then, we should better use the staircases, because we can act there for ourselves and by our own decision. We should better make the staircases more useful in case of fire emergency. But staircases could not be used due to the chimney effects, ..." and I came up with the thought "Then, we should just prevent the staircases from becoming like a chimney!"
The solution to this requirement was trivial and came up immediately: "We should just open the windows of the staircases in case of fire! If we make large openings in the staircases, the chimney could be interrupted. Even if we have a sequence of staircases from the ground floor to the top, we should just put large openings on every story of the staircases to break the air flow and smoke at every story." This idea is based on the simple knowledge which pupils in elementary schools or junior high schools learn in classes.
I jotted this idea down on a small piece of scratch pad at hand in a few words and continued my translation work.
2.3 Writing down the solution in detail
The idea written on the pad gradually grew in my mind, and I became confident that the idea of setting large openings on every floor at the staircase is simple yet very effective solution to this problem. So, a week later, in the morning of August 7 at home during the university summer vacation, I started to write down my idea. Soon after starting, I began to use the format of 'Description of an Invention' which I used to write in Fujitsu Labs for showing our new inventive ideas to patent specialists for their help. Following the format, I wrote down my idea with a number of small goes and backs.
The main items of the format 'Description of an Invention' are as follows:
2. Conventional means and their problems
2.1 Application areas of the invention
2.2 Conventional means
2.3 Problems of the conventional means
2.4 Tasks to be solved
3. Means to solve the problem (i.e., explanation of the basic idea of the invention)
4. Examples of application
6. Claims for the patent application (possibly a draft of claims)
During this writing work, I considered various points of the problem and the solution and described them in the manuscript. Thus my thought became much clearer than that at the stage of the memo on a piece of scratch pad. If you ask me "Did you use TRIZ and/or USIT process?", I feel some difficulty to answer. I did not use any formal process of TRIZ/USIT, but I certainly used many principles and thinking ways of TRIZ and USIT together with many other experiences and background knowledge in my mind. I just used all my ability during thinking and writing, without explicitly following any single methodology except the format itself. Even so, the following two points are clear:
Fist, in defining the problem, I chose "To keep the staircases safe for evacuation, by preventing them from becoming like chimneys even in case of fire". This problem definition has determined the whole problem solving process for the present work. I now believe I used the USIT's way of thinking during this problem definition process.
Second, I solved the problem with the final solution: "In ordinary times, the staircases are convenient and comfortable, located inside the building, whereas in case of fire, by opening the windows of the staircases widely towards outside, the staircases serve as the safe evacuation routes without the chimney effect and as the bases for fire-distinguishing and rescue activities." This solution clearly reflects the TRIZ' Separation Principle in time. During solving, I had clear recognition of a technical contradiction (between convenience/comfort and fire-preparation) and a physical contradiction (i.e., staircases should be located inside and simultaneously outside the building) of this problem. And I was also well aware of my using the TRIZ way of solving the contradictions. I became aware of these points right after the start of the description work.
The following sections record my draft of the 'Description of an Invention' written on August 7 and describe my thinking process during the initial thought on August 1 and during the drafting work on August 7 as recorded and analyzed on August 15 and 23-24 .
3. Process of Problem Definition
The actual process of the initial setting up of the problem for the present work was done in my mind without writing or even speaking any sentence or keyword. The process in my mind may be explained more explicitly as follows.
3.1 A system of problem
Examining the sentences of Salamatov's exercise problem, they are parsed to show its logic more clearly in the form of a 'problem tree' as shown in the following figure:
--> Means of preparing against fire are demanded.
--> We focus on the means of escaping and rescuing people from fire.
--> Escaping with ordinary means:
--> Escaping with elevators ## No. Elevator may turn into a chimney.
--> Escaping through staircases. ## No. Staircase may turn into a chimney.
--> Rescuing people by firemen and rescue services.
--> Rescuing with a telescopic ladder. ## No good for over 12th floor.
--> Rescuing by the rescue service (with ropes, ladders, helicopters, etc.)
## Not accountable enough.
--> Rescuing people through the windows
--> Means of emergency escaping:
--> Emergency escaping with the 'rescue hose' ## Not applicable for everybody.
--> Emergency escaping with Vilchinsky's 'gravitational elevator'
## No. Much room for improvement.
--> New means for emergency escaping demanded.
"So we should go back to the starting point of this problem and reconsider for the solution to escape and rescue people from fire. It should be most important for us to be able to escape or to be rescued from fire in its early stage. So we should find some effective solution on the basis of 'escaping with ordinary means'; it must be practical and widely applicable. Let us examine the reasons why such means were rejected so far. The text says 'because the elevators and staircases turn into chimneys in case of fire'. We should think over this reasoning again. Do they necessarily become like a chimney? Is there any means of avoiding them from becoming like a chimney? ..." This way of thinking was the key to the problem definition in the present work.
As described above, it is most important to think over the whole problem (i.e., 'the means of escaping and rescuing people from fire' in the present case) and to find the overall structure of the problem (i.e., 'the system of problem') including various conventional approaches. The specific problem currently requested (i.e., 'to improve Vilchinsky's emergency escaping device' in the present case) should be re-examined in the perspective of the whole problem system.
3.2 Problem definition in USIT
This way of thinking corresponds well with the USIT method in its problem definition stage. USIT (as well as TRIZ in its essence) recommends to think the problem as a system (even though the representation of the 'problem tree' does not belong to USIT). Sickafus advises to select such a problem that the solution to it may bring significant profit and to focus on the most essential issue in the problem. In the problem definition stage of USIT, these points are considered through the discussion in the problem solving team and the guidance by the leader (Note: USIT recommends to be carried out by a group jointly made of engineers of the specific topic and USIT practitioners). As a result of such discussion, USIT often guides the team to a problem definition different from and more essential than the initial one defined by the person who brought the problem.
Furthermore, in the stage of problem definition, USIT requests the team to consider and discuss: "What is the problem? What are the plausible root causes? What is the (physical) mechanism of the problem?" In the present case, USIT has guided me to consider "Why escaping and rescuing people from fire is so difficult?" So it has made clear to me: "Escaping from fire is difficult because elevators and staircases may become unavailable in case of fire." Then I asked to myself "Why do they become unavailable?" and get the answer "Because they turn into chimneys". Further I asked to myself "Then, why do they turn into chimneys? What is the physical mechanism of it?" Thus I came to understand the problem of staircases having the shape of a chimney, i.e. a tall hollow cylinder without openings. As a result of these series of questions, I have obtained the problem definition of the present case quite naturally, i.e. "To keep the staircases safe for evacuation, by preventing them from becoming like chimneys even in case of fire". With this problem definition, I have come up with the initial idea almost immediately.
3.3 Defined problem is the title of the invention
The first part of the format 'Description of an Invention' corresponds mostly with the consideration and result of the problem definition stage, and is written in this case as follows:
Design of staircases for high-rise buildings preventing the chimney effects in case of fire
2. Conventional Means and Their Problems
2.1 Application Areas of the Invention
The present invention concerns with the design of high-rise buildings with several or more stories, especially with the design and structure of such buildings taking prior consideration of emergency escaping means in case of fire and earthquake, and more particularly with the design of staircase rooms of such buildings.
4. Process of Analyzing the Conventional Means and Their Problems
The format of 'Description of an Invention', i.e. essentially a 'Patent Application Form', requests us to describe conventional means known so far and their problems. This step, though one might feel it tedious and often like to skip in the process of 'creative problem solving' like TRIZ and USIT, was mandatory in the format for claiming the creativity/novelty of the idea. The description work of this section was found very fruitful in the present case to examine and strengthen the new idea.
4.1 Overview analysis
In the first part of Section 2.2 of the document, I described overviews of various conventional means for escaping and rescuing people from fire and put stress on the necessity of effectively using the staircases:
As ordinary means to go upstairs or downstairs in high-rise buildings, (a) elevators, (b) escalators, and (c) staircases are widely used. As emergency means to go upstairs or downstairs for escaping in case of fire and earthquake, however, the elevators are usually prohibited to use and the escalators are not convenient even in operational cases, thus the staircases should make a major role.
... <description of staircases is cited later> ...
Besides the ordinary means mentioned above, there can be various means for rescuing people who are left at higher stories of a burning building. They include emergency descending devices, fire engines with long telescopic ladders, helicopters, etc. These emergency means, however, are to be used for rescuing people who have failed to escape safely at the earlier stages of fire. The present invention intends to make larger chances of escaping from fire safely at the earlier stages.
2.3 Problems of the Conventional Means
High-rise buildings have been built higher and larger and in ever increasing numbers. Once such a building gets fire, the fire spreads not only horizontally at the floor but also vertically to the neighboring floors. The fire spreads upstairs through ducts for air-conditioning and pipes and cables, and through vertical spaces for elevators, escalators, and staircases due to the chimney effects. The speed of upward extension of the fire is often surprisingly fast, and it becomes difficult to rescue people who are left at the floors higher than the burning floor.
In case of fire or earthquake, it is the general policy of today to prohibit the usage of elevators for emergency escaping. This is because the elevator may abruptly stop its operation due to some damage in the driving or controlling system and may confine people locked inside it, and because people in the elevator have a high risk of being exposed to heat, smoke, and toxic gases coming in due to the chimney effect of the elevator shaft.
Escalators may be operational at the initial stages of fire, but probably not when the damage of the fire spreads. Staying escalators can be used just like staircases, but are slippery and not so convenient.
Thus it has much significance whether the staircases are available as safe escaping routes or not. If they are available and safe, people can make their own ways out for themselves judging the situations. So let us examine the problems in staircases.
4.2 Classifying conventional staircases
Then I went ahead to describe the conventional designs of staircases and their problems in a systematic way. Drafting this part was later found the most important in the documentation work of the present case. I tried to write down my knowledge and experiences in a way systematic and logical as much as possible. Since I am not a specialist in architecture nor in fire distinguishing, my knowledge and experiences on the present topic are at the level of common sense, similar to most of the readers of this case study.
I tried to recall the images of a large number of high-rise office buildings, department stores, hotels, university buildings, residential apartment buildings, shopping center buildings, etc. in Kasumigaseki and Shinjuku (i.e., downtown Tokyo) and many other areas and countries, and then tried to categorize the design features of their staircases from the view point of emergency cases of fire. Eventually I classified the structure of staircases into two categories, i.e. those inside or outside the building, and then into four categories in total. In Section 2.2 (Conventional Means), the staircases are described as follows:
From these points of view as emergency escaping route, the structure of staircases of high-rise buildings may be classified in the following categories:
(A) "Internal Staircases": staircases built inside the buildings
(A1) "Non-separated Internal Staircases":
Open staircases which are not separated from the rooms of the floor in the sense of fire protection.
(A2) "Separated Internal Staircases":
Staircases which are separated from the rooms of the floor in the sense of fire protection and are formed as separated rooms by themselves.
(B) "External Staircases": staircases built or attached outside the buildings
(B1) "Emergency-Only External Staircases":
External staircases which should be used only in case of emergency and are prohibited to use in ordinary days by locking the door between the staircase and the floor room. The emergency-exit doors can be unlocked easily only from inside. The staircases are regarded as being outside the buildings in the sense of theft and invasion protection.
(B2) "Free-Access External Staircases":
External staircases which are used every day as ordinary passage accessible freely from outside the buildings. From the viewpoint of theft and invasion protection, the staircase and its connected passage are regarded as being entirely outside the buildings. Entrances to the rooms of each floor are regulated by locking the doors individually. This design of staircase is often used in residential apartment buildings of low and high stories.
4.3 Analysis of problems in conventional staircases
In Section 2.3 of the 'Description of an Invention', problems of these conventional staircases must be described in a convincing way. So I analyzed the problems of each of the four categories of staircases. By reasoning in the common sense, and probably somehow on the basis of my scientific/technological background, I described this part as follows:
(A1) "Non-separated Internal Staircases":
At the floor where the fire starts burning, flame, smoke, and toxic gases can easily enter into the open staircase. Consequently the fire can quickly extend towards upstairs. Thus, this design of staircases is usually avoided in high-rise buildings. Apparently-open-style escalators and staircases at shopping floors of high-rise buildings usually have fire-doors or shutters installed to separate them from the floor rooms in case of fire.
(A2) "Separated Internal Staircases":
In preparation against fire, this type of staircase are separated with firewalls from the rooms of the floor and are installed with fire-doors at the entrances to the inside passages. Being separated from the floor rooms, the staircases are built as separated rooms by themselves and forming a vertically-arranged sequence. This is the typical structure of staircases in today's high-rise buildings. However, if the fire-door is not closed tightly at the burning floor due to some failure, defect, or damage, then enter flame, smoke, and toxic gases into the staircases and go upwards all through.
In today's high-rise buildings, this type of staircases are often built in a somewhat hidden space near the elevator hall, and are built with solid walls often without windows. This closed structure may come from necessity of air-conditioning in ordinary days. However, the closed and vertical hollow structure of this type of separated staircases causes the chimney effects in case of fire.
(B1) "Emergency-Only External Staircases":
This type of staircases are to be used only in cases of emergency. Thus the staircases are built with simple and humble structure, and are often maintained poorly. The management of locks of these emergency exit doors is often the problem concerning to the invasion and theft protection. The locks must allow to be opened easily and freely from inside at any time expecting the emergency cases, but must not be opened without keys from outside. If someone leaves an emergency door open for some reason, the problem of invasion and theft arises.
This type of staircases are usually built on the outside wall without cover; so they do not involve the chimney effects, and are not suffered from being filled with heat, smoke, and toxic gases. This is a big advantage as an emergency-escaping route. From the viewpoints of style and invasion protection, however, this type of staircases are rarely adopted in modern high-rise buildings.
(B2) "Free-Access External Staircases":
The advantage of this type of staircases is similar to that of (B1); since its structure is not closed, it does not involve the chimney effects, and is not suffering much from flame, smoke, and toxic gases in case of fire.
Since this type of staircases are used every day and regularly and are freely accessible from outside, the means of regulating the entrance into the floor rooms must be provided. If the floors or the individual rooms are used or operated more or less independently by some limited number of people, they may be managed to lock separately. But such a locked-door system might be inconvenient if rooms at multiple floors are used by a large number of people such as those belonging to a business unit. Since the areas of staircases are outside the buildings, they are not air-conditioned and sometimes exposed to wind and rain.
5. Further Analysis of the Problem for Defining the Tasks to Be Solved
The format 'Description of an Invention' requests next to describe 'Tasks to Be Solved'. Thus we are guided to summarize the problems of various conventional means and to conclude the tasks to solve or the targets to obtain.
So I started to summarize the problems of the four categories of staircases: "Category (A1) is defective because the fire can spread easily. The separated internal staircases of Category (A2) aim to prevent the fire from extending and to serve as emergency escaping routes, but in fact have the drawbacks of becoming useless once the fire or smoke enters due to the chimney effects. From the viewpoint of safe escaping routes in case of fire, the staircases (B1) and (B2) built on the outside walls of the buildings are much better.
Then, should we just adopt such external staircases? No, unfortunately. Staircases built on the outside walls of the building have their own problems concerning to the safety in ordinary days. The emergency-only staircases (B1) have the risks of being left open either intentionally or unintentionally. The free-access external staircases (B2) are often used at residential apartment buildings, where every flat is managed to be locked independently by the residents. Such scheme of safety management may not always be convenient for big buildings of various usage."
Thus in Sections 2.3 and 2.4 of the 'Description of an Invention' document, I wrote as follows:
2.4 Tasks to Be Solved
Staircases of high-rise buildings have to be designed and built so as to be not only convenient, comfortable, and safely guarded for everyday ordinary use but also safe and secure as emergency escaping routes in cases of fire and earthquake. In particular, they must be designed not to cause the chimney effects in case of fire and not to get suffered from being filled with flame, smoke, and toxic gases of fire.
It is also desirable to have subsidiary functions that at the staircases people can stay safely on a temporary basis even during the fire, look around and judge the current situations of the building and fire, and moreover that the staircases serve the firemen and rescue team as their bases for carrying out their full activities.
Hence it must be important to record in the present case-study paper the actual way of my thinking while I was drafting the section of 'Tasks to be solved' and preparing for the next section of 'Means to solve the Problems'. My thinking process is explained in the next section with explicit reference to TRIZ concepts.
6. Deriving and Solving Contradictions by the Use of TRIZ
6.1 Revealing the technical contradiction
The analysis described in the previous section has clearly shown the following points: For the purpose of ensuring the emergency escaping routes in case of fire, the staircases should be built not inside the building (i.e. Categories (A1) and (A2)) but outside the building on the outer wall (i.e. Categories (B1) and (B2)). However, from the viewpoints of safety in ordinary days and the convenience and comfort for everyday use, staircases built inside the buildings are much superior to those outside; thus the staircases built outside the buildings may be adopted only for buildings of limited types of usage.
This statement corresponds exactly to the definition of a 'Technical Contradiction' in the TRIZ theory. We now consider a building as a system and are dealing with a staircase as its subsystem. In the staircase system, if we want to improve the system's function as an emergency escaping route (by locating the staircase on the outside wall), the system's functions of convenience, comfort, and safety would become intolerably worse. Namely, we are facing with a type of contradiction where "If we improve one aspect of the system, some other aspect get intolerably worse." This type of contradiction is called a 'Technical Contradiction' in TRIZ.
Being faced with such a contradiction, practical engineers often try to seek for a trade-off. Since no good compromise has been found in this case, however, most buildings of several stories adopt emergency-only external staircases (i.e., B1) while high-rise buildings adopt separated internal staircases (i.e., A2) without ensuring emergency escaping routes. Hence breaking this contradiction is the task for us to solve in the present case study.
6.2 Revealing the physical contradiction
When we consider the above technical contradiction more carefully, we may naturally notice another view. It is the view distinguishing the time period of emergency from much longer time period of ordinary days. We want staircases to be convenient, sheltering from wind and rain, air-conditioned, and safely guarded for the use of ordinary days. Emergency case of fire is the exceptional period of time, when we want to ensure the staircase to be the route for escaping safely from fire. During this special time period of fire nobody cares sheltering from rain and wind and safety from theft, etc.
This kind of characteristics are always examined in the USIT method at the stage of 'Analysis of space and time characteristics'. There continues a long period of ordinary time of everyday life, and suddenly the emergency of fire may arise. What and how to do during the ordinary days in preparation against unforeseeable emergency is the task of disaster preparation.
After thinking in this manner, the requirements for the design of staircase can be described as follows: "In order to be convenient, sheltering from wind and rain, air-conditioned, and safely-guarded against thefts in ordinary days, the staircase should be built inside the building, whereas the staircase should be built outside the building so as to ensure it as the safe escaping route in case of fire."
The above statement corresponds exactly to that of a 'Physical Contradiction' in TRIZ. The situation where "An aspect of a technical system is requested toward positive and toward negative directions at the same time" is called a 'Physical Contradiction' in TRIZ. In the present study, the staircase system is requested to be built inside the building to fulfill various requirements in ordinary days, whereas it is requested to be built outside the building for the requirements in case of fire. Namely, the staircase is under the contradictory requests that it should be built inside the building and outside the building at the same time.
6.3 TRIZ' Separation Principle solves the physical contradiction and gives us a puzzle
TRIZ recommends us to solve problems by reformulating the problem into the Technical Contradiction and then further into the Physical Contradiction. Especially, TRIZ provides very clear and powerful principles for solving Physical Contradictions. They are the 'Separation Principles'. When we are faced with the contradiction where one aspect of the system is requested to be made in the positive and negative directions at the same time, TRIZ asks us: "Do the two opposite requests need to be fulfilled really simultaneously?" It urges us to reconsider more closely: "Can't you separate the two requests with respect to space? with respect to time? or with respect to some other condition?" In the present case, it is quite trivial that the two opposite requests (i.e. to be built inside/outside the building) refer to separated time periods, i.e. ordinary days on one hand and emergency time of fire on the other hand.
The guideline in TRIZ to solve a Physical Contradiction with the separation principle is clear as follows: "In case the two requests are separable by time, then during the time period when the request is positive we should fulfil the positive request, whereas during the time period when the request is negative we should just fulfil the negative request". In the present case this means: "During the ordinary days the staircase should be built inside the building so as to be convenient, sheltering from rain and wind, air-conditioned, and safely guarded, whereas during the emergency time of fire the staircase should be built outside the building so as to ensure it as the escaping route". We must think over the real meaning of this message and how we can realize it, at the next step.
6.4 Needs to introduce a physical principle
Now in the step to realize the stated requirement, some physical principle (or chemical, biological, social principle, etc.) needs to be introduced, says Salamatov . In our case, we have to introduce some physical principle to realize the puzzling requirement, i.e. "To build the staircase inside the building during ordinary days and outside the building during the time of fire".
In the present case, such a principle (or a clew to solve the puzzling requirement) is easily found among common sense knowledge of ordinary people: "To equip big windows (i.e. openings) at every floor of the staircase and open them widely in case of fire, so as to achieve the effects similar to that of having the staircase rebuilt outside the building."
This clew has come from the common-sense knowledge, but in fact it is based on a physical principle of the chimney effect. The staircases inside the buildings have the demerits of quick extension of fire and smoke because of the chimney effects and of becoming unavailable as the escaping routes. With the intention of avoiding the chimney effects, the external staircases have been designed.
The chimney effects may be described in a somewhat scientific way as follows: If there is a hollow cylinder stretched long in the vertical direction and if the bottom (or middle) part contain hotter air, then a strong airflow is induced in the cylinder from the bottom to the top. If an opening is made in the middle of the cylinder, the 'chimney' is effectively divided into two, making the airflow localized and weak as a whole. Since we know well about this physical effect, the naive idea of making windows at every floor of the staircase is understood to have some scientific basis and is expected to work.
6.5 USIT guides us to consider the physical mechanism at a much earlier stage
As explained above, TRIZ supposes to refer, after formulating the (physical) contradiction, to some scientific/technical principles for finding a solution to the contradiction. However, the consideration with scientific/technical principles should be made not only in such a late stage of problem solving process. In fact, in USIT the physical mechanism of the problem is examined and the plausible root causes are searched for at the early stage of the problem definition.
Thus, in the USIT approach, at the initial stage of considering the present problem, the essence of the problem is found to be "Staircases built inside the buildings behave like a chimney in case of fire and become unavailable as escaping routes", and then its physical mechanism is considered. The (scientific/engineering) consideration about the chimney effects leads us to understand that the long hollow structure in the vertical direction causes the effects. "If it's the case, we should just make windows as openings and divide the hollow cylinder into smaller ones." -- this idea will certainly come out at one easy step.
7. Constructing Solutions and Implementing Them with Technology
We have now solved the contradictions and obtained a basic idea clearly. Hence at the next step, we should expand the core idea and make various technical considerations to construct united and practically feasible solutions. I carried out this stage of work by drafting Section 3, i.e. 'Means to solve the problems', of the 'Description of an Invention'. I wrote the section with a number of minor revisions. The orders of the ideas coming out were not the same as their orders written in the final document, of course. However, the main process of thinking was nearly the same in order as the final document.
7.1 Description of the solution
Section 3 of the document is cite below:
After the analysis of the problems as described above, we have obtained the following solution for the staircase design:
(1) To fulfill the convenience in ordinary time, the staircase should basically be a kind of 'Internal Staircase'.
The staircase should be for every-day use, not exposed to wind and rain, comfortably air-conditioned, and safely guarded.
(2) The staircase should be of a 'Separated' type of 'Internal Staircase', in order to prevent the extension of fire and to ensure it as an emergency escaping route.
The staircase must be separated from the rooms of the floor with firewalls and fire doors.
Even if the rooms of the floor are burning, the fire should be kept from entering into the staircase.
The fire door should block the flame, smoke, and toxic gases, as surely as possible.
The staircase must be built with non-inflammable materials, which should not produce toxic gases in fire.
It is suggested to set a fireproof window in the fire door at a low position near the floor.
It will guide people towards the lower position.
Firemen and rescue team can look into the room without opening the fire door.
The window at such a low position will not be attacked with fire so much.
This means that the Internal Staircase changes its structure into that of the External Staircase only in case of fire.
For this purpose the staircase must be located towards the outside of the building.
Opening the windows performs the role of eliminating the chimney effects. The Internal Staircase which was a hollow cylinder (i.e. like a chimney) from the bottom to the top inside the high-rise building now has the openings at every floor and effectively loose the structure of the chimney. With the elimination of the chimney effects, the staircase now plays less role of letting the fire extend towards upstairs.
The smoke and toxic gases getting into the staircase may go out through the openings, without densely filling in the staircase on the burning and the neighboring floors.
At the staircase people can breathe the fresh outdoor air. Thus people may be allowed to stay there safely for the time being even during the fire.
(4) The open windows and the halls of the staircase may be used as the entrance and action bases for fire-distinguishing and rescuing activities during the emergency.
The people escaping from fire and needing rescue can call help from there to the rescue team outside the building.
Devices for emergency exit may be equipped there.
The firemen and rescue team can get into the building through the open windows at the staircase (maybe with the help of a ladder or a helicopter).
It is suggested to make it possible for the escaping people to look around the outside walls of the building from the staircase.
To look around the outside walls, the staircase itself may be stuck out from the wall; but as an alternative, some concave mirrors may be set outside the staircase to see the walls (only in case of fire).
The windows of the staircase may be opened by hand on site. But this hand operation may not be effective in case of emergency. So the windows should better be opened remotely at the control center.
The windows may be opened either on site or at the control center; they may be closed on site.
If any window of the staircase is opened by hand in ordinary situation, an alarm should be shown at the control center of the building.
The openings should better be made of transparent glasses, so that the people who use the building easily recognize them as the emergency openings.
The glasses of the windows should be reinforced so that once they break they are broken into small round pieces without the danger of injuring people.
7.2 Designing the solution in a top-down style
These ideas are written in a top-down style from the main principle of design to some details. First the new design of the staircase is specified as an 'Internal Staircase', and then of the 'Separated type', similar to the (A2) type of the conventional design. At item (3), it is further specified that the windows of the staircase should be opened widely in case of fire. This specification is the essence of the solution in the present invention. The items in (1) and (2) describe the basic design of the staircase in the ordinary days, and form a unified solution together with the item (3).
The specification (4) makes the openings and the halls of the staircases serve as the entrances and action bases for the fire-distinguishing and rescuing activities, and claims functions as additional merits. TRIZ recommends that, after introducing a new solution into a part of the system, one should examine other parts of the system to make full use of the merits of the new solution and further improve the super-system. In case of fire, the newly-designed staircases are available not only to go down for escaping but also to stay there safely for some time even while the building is burning. The space of safe staircase should be used actively for fire distinguishing and rescuing people. The widely opened windows make it easier for the firemen and rescuing teams to perform their activities by keeping communication with the staff outside the building; it is a merit that the controlling staff of the fire-fighting troop can observe their team in action and can guide them.
The item (5) specifies how to control this facility of windows. In the design of technical systems, it is essential to describe how to control them. I wrote the control system after imaging a modern high-rise buildings. It also specifies the control scheme so that the people on site can take their best way after their judgement in the emergency.
7.3 USIT's characteristic time axis
In the process of drafting the present solution, the method of 'Analysis of space and time characteristics' in USIT was very useful and illustrative for me. USIT recommends to analyze the characteristics of the system in accordance with the 'time axis' specifically taken for the system. Thus, various possible situations in case of fire are considered along such a time axis: Ordinary days without fire; the first stage of a small fire (and getting out of the floor/building); the second stage of a fire beginning to burn in a floor (and urgent evacuation of the floor/building); next stage of fire burning in multiple stories (and emergency escaping from the building and rescuing people); more serious stage of fire when the smoke and fire enter into the staircase (and emergency escaping and rescuing people); and so on. Examining about these stages of fire step by step in mind was helpful to think of the problems and necessary solutions in different stages.
In the present study, the solutions described above were obtained through the knowledge in the level of common sense. If one deals with different problems, one may often need much more knowledge in technical specialties. Even so, I feel there may be rather large areas where the essence of solutions can be found by non-specialists.
8. Concerning to the uncompleted sections in the 'Description of an Invention'
In the document of 'Description of an Invention' I left the following three sections uncompleted at the stage of August 7:
<Not completed yet.>
<Not completed yet.>
6. Claims for the patent application
<Not completed yet.>
The second uncompleted part is the description of 'Effects'. The effects and performance of the new design must be tested at least by model experiments and be confirmed in practice. It is also desirable to derive a designing guideline for achieving the effects as expected.
The last part uncompleted in the document is the statement of claims as patents. To fill in this part, one should survey conventional techniques and previous patents thoroughly and should write down what is claimed as new original ideas in the present application of a patent. It is usually advised to write in general terms, so as not to restrict the claims unnecessarily narrowly, and to make the claims cover as widely as possible. Since it is difficult to write this part professionally, it is usually recommended to write down the drafts and ask patent specialists to brush them up.
So, on August 7, I left these three sections in the 'Description of an Invention' document blank. It was natural for me, because my idea and my experience on the new solution were not concrete and not in practice yet at that time.
9. What to Be Done in Future to Establish the Solution as New Techniques
After finishing the drafting of the 'Description of an Invention', I thought this solution could become a patent. So I searched the patent database of Japanese Patent Office on the Internet. Using the keywords 'evacuation AND staircase', I got 56 hits of Japanese patents. Quickly reviewing the patent abstracts, I found nothing relevant. Furthermore, I have never seen buildings whose staircases are designed in the sense of the present idea.
It was certainly of some interest for me to obtain a patent on this idea, if possible. But I declined to do so, considering the tedious work of finding some appropriate collaboration company for filing the patent and of fighting in courts to realize the benefits of the patent. Moreover, if I should seek for the possibility of patent, this idea would have to be kept secret for a certain period, and would be much delayed and limited in being realized in society. So having thought for a week, I have decided not to try to file a patent on this idea but to publish it as widely as possible so as to be realized in a huge number of buildings in Japan and in the world. Fortunately, I was in a position to be able to publish this idea freely without requesting any permission from others.
Thus on August 15 I wrote a preface for publishing this work as a TRIZ/USIT case study which is going to contain three parts. Then on August 23-24, I wrote the parts (a) and (c) for explaining how I got the initial idea and how I thought while writing the problem analyses and solutions. They are posted on my Web site on August 24, 2000 in three parts including the 'Description of an Invention' as part (b). At the end of part (c) of the posting I wrote as:
As written in the preface of this page, I have just formed and documented the present idea, and decided not to try to file a patent but to publicize it as widely as possible. It is desirable and necessary to do some model experiments for checking the performance, to design and implement in real high-rise buildings, and to make design guidelines if good performance is achieved; all these work will need commitments by specialists in the fields of architecture, fire fighting, etc.
I should appreciate it very much if readers of this article would examine the present idea and improve it further into good solutions for safe emergency escaping from fire.
The present author also wishes that this paper should be read as widely as possible in the world to prepare against fire casualty.
10. Recent Information
Since posting this case study, the present author had four chances of presenting this work in detail as a part of TRIZ/USIT introduction talks. The audience, about 200 engineers in total, have accepted this work interesting. One engineer specialized in architecture and novice in TRIZ found this idea something like a Columbus' egg. A manager of construction department at a manufacturing company wrote to me that the bureaucratic regulations in architecture would become the main obstacle for implementing this new idea in Japan because Japanese bureaucrats believe in the safety of current 'Separated Internal Staircases' in case of fire.
I watched 'Towering Inferno'  again on VCR recently. The movie gave me vivid images and new viewpoints. I feel that the present idea provides some solution to the case of the movie. But I also understood the disastrous power of the fire bursts and difficulties coming from various human mistakes/failures.
Recently I found and read a book specialized on the present topic in Japanese: "Fire Disasters of High-, Very High-, and Ultra High-rise Buildings in the World: The Facts and Solutions for Preventing Fire and Evacuation", by Takeshi Morita . As a specialist in fire-fighting, the author reports in detail 15 cases of disastrous fire of high-rise buildings all over the world and discusses various week points in modern buildings. His description mostly confirms the points I have mentioned above, and warns more strongly the difficulty of keeping fire and smoke from entering into the staircases of the 'Separated Internal' type. He proposes a new design principle for making high-rise buildings safer against fire. His design eliminates all the vertical hollow structures inside the building, stacks stories of solid floor/ceiling without any vertical holes, surrounds the stories with open terraces, and then attaches every vertical structure, such as elevators, staircases, kitchen and toilet facilities, ducts, pipes, cables, etc., on the outer wall. His design is much more drastic and fundamental than mine. It must be very interesting to examine his solution from our viewpoints of refined and broader usage of the 'Separation Principle' in TRIZ. I am looking forward to discussing with Mr. Morita in near future.
11. Conclusion: Lessons from the Present Case Study
In conclusion, following lessons are obtained from the present case study:
(1) Problem definition and the sense of seeking for real problems are important. USIT is useful at this stage.
(2) Mastering main concepts and the way of thinking for problem solving is prerequisite. TRIZ concepts of technical system evolution and contradiction solving are essential.
(3) It is not always necessary to take a formal procedure in problem solving. Essences of various techniques/procedures may be used freely and sometimes informally. Simplified TRIZ (e.g., USIT) are useful.
(4) It is helpful to use TRIZ concepts/techniques during the processes of every-day problem solving. TRIZ concepts are useful while writing notes, papers, patents, etc. and doing any other R&D activities.
(5) General background of science/technology and insight into the mechanisms and root causes form the bases. Training oneself is necessary even though knowledge bases will be of some help.
After the present experience, I wrote as follows in my preface to the Japanese Edition of Salamatov's TRIZ textbook :
 Yuri Salamatov, "TRIZ: The Right Solution at the Right Time", Insytec, 1999; (Japanese Edition) Nikkei BP, Nov. 2000.
 Kalevi Rantanen, "How to Learn/Teach TRIZ -- A Personal View on Savransky's Book", TRIZ Journal, Dec. 2000; TRIZ HP Japan, Dec. 2000.
 Toru Nakagawa and Valeri Souchkov, "Salamatov's TRIZ Textbook: Japanese Edition and Q&A's on the English Edition", TRIZ HP Japan, Nov. 2000.
 Roni Horowitz and Oded Maimon: "Creative Design Methodology and the SIT Method", 1997 ASME Design Engineering Technical Conference, Sacramento, California, Sept. 14-17, 1997; TRIZ HP Japan, Mar. 2000.
 Ed. N. Sickafus, "Unified Structured Inventive Thinking: How to Invent", NTELLECK, Grosse Ile, MI, 1997, 488p.
 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. (in Japanese); TRIZ HP Japan, Apr. 2000 (in English).
 Toru Nakagawa, "Staircase Design of High-rise Buildings Preparing against Fire (TRIZ/USIT Case Study)", TRIZ HP Japan, Aug. 24, 2000 (in Japanese), to appear (in English).
 "TRIZ Home Page in Japan", WWW site edited by Toru Nakagawa. URL: http://www.osaka-gu.ac.jp/php/nakagawa/TRIZ/eTRIZ/ (in English), http://www.osaka-gu.ac.jp/php/nakagawa/TRIZ/ (in Japanese). (Note: These are abbreviated here as "TRIZ HP Japan".)
 "The Towering Inferno", American movie directed by Irwin Allen John Guillermin, 1974.
Takeshi Morita, "Fire Disasters of High-, Very High-, and Ultra High-rise
Buildings in the World: The Facts and Solutions for Preventing Fire and
Evacuation", Modern Fire-Fighting Inc., Tokyo, Nov. 1998, 219p. (in Japanese)
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 Nov. 1998 he founded the public WWW site "TRIZ Home Page in Japan" and serves as the Editor.
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.
Editor's Note (Toru Nakagawa, April 4, 2001)
During my presentation
at TRIZCON2001, I showed the following slide. This understanding
of the essence of TRIZ is the basis of my closing phrase in the TRIZCON2001
|Essence of TRIZ:
technical systems evolve
towards the increase of ideality
by overcoming contradictions
mostly with minimal introduction of resources.
Thus, for creative problem solving,
TRIZ provides with dialectic way of thinking, i.e.
to understand the problem as a system,
to image the ideal solution first, and
to solve contradictions.
Last January, when I sent the preprint of my TRIZCON2001 paper to Dr. Yuri Salmatov in Krasnoyarsk, he kindly wrote back to me via e-mail as:
Dear Prof.Nakagawa,As I wrote in Sections 9 and 10 above, the present idea should be examined in experiments and further improved by overcoming various difficulties so as to provide real solutions to safer staircase designs preparing against fire.
I carefully studied your article for TRIZCON2001. Thank you.
The whole process of the problem solving is shown quite
convincing and in full details. Perfect decision!
My best congratulations with perfect work on TRIZ!
I hope that will be good advertising of TRIZ in Japan.
|1. Introduction||2. The beginning||3. Problem definition||4. Analysis of conventional means||5. Tasks to be solved||6. Solving contradictions||7. Constructing solutions|
|8. Uncompleted sections||9. What to do in future||10. Recent information||11. Conclusion||Editor's Note||Original Posting. Feb. 28, 2001|| TRIZCON2001
|Home Page||New Information||Introduction to TRIZ||TRIZ References||TRIZ Links|
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Last updated on Apr. 25, 2001. Access point: Editor: firstname.lastname@example.org