Kraev's Korner: Overcoming Mental Inertia - Lesson 11

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  • By Val Kraev

    Editor's note: Kraev's Korner was first published in the newsletter of the Altshuller Institute in 2005. Our thanks to the Altshuller Institute and the Technical Innovation Center for letting us reprint this educational series. Previous lessons can be found by searching the TRIZ Journal's archives.

    When we open a door with a key, lace our shoes or walk along the street, we typically do these routine operations mechanically – without thought. We do not think about the sequence for these activities. We minimize intellectual energy and time. When we try to improve existing processes or develop something new, we involuntarily attempt to apply solutions and approaches that are already known to us. This "obliging" previous experience keeps us on the same beaten track and suggests customary, old solutions that have been done before and cannot provide us any innovative results. This phenomenon is termed psychological or mental inertia. During the creative process of searching for new solutions, mental inertia can exert a negative influence.

    In order to overcome psychological inertia, there are different methods in TRIZ that can be applied that extend our customary view about a problem and broaden ways for solving it. With the help of these methods, it is possible to consider a problem from diversified and unexpected points of view. Multi-screen thinking, dimensions-time-cost and modeling with smart small people are the most popular of these methods.

    Multi-screen Thinking Method

    The multi-screen thinking method mentally represents a developed system with the application of at least nine screens. The system itself, its super-system and its sub-system are each represented in the past, present and future. This approach leads to the development of new concepts for a solution and, thus, overcoming failures.

    Table 1 shows this method used for improving a flat iron that removes wrinkles from clothing. The selected system, the typical modern electrical iron, is placed in the central table square. The choice of a sub-system depends on what part of the device we wish to improve. Sub-systems for an iron can be the housing, temperature control regulator, power cord, sole plate, etc. In perfecting this device, we will define future changes of the system and super-system. For this example, we select an electrical sole plate as a basic sub-system of an iron – the present sub-system.

    Table 1 shows this method used for improving an iron (that removes wrinkles from clothing). The selected system, the typical modern electrical iron, is placed in the central table square. The choice of a sub-system depends on what part of the device we wish to improve. Sub-systems for an iron can be the housing, temperature control regulator, power cord, sole plate, etc. For this example, we select an electrical sole plate as a basic sub-system of an iron – the present sub-system. The present super-system is the new compound system in which the iron will be only a part – it can be a system including an iron and an ironing board with linen pad. It is not difficult to fill the past column, but it is an important step because the past of the specific system can lead toward the direction of a future development.

    Table 1: Multi-screen Analysis of a Flat Iron
    Super-systemTable-linen-ironIroning board-linen-ironReflecting ironing board-linen-iron
    SystemCharcoal ironElectrical ironMicrowave iron
    Sub-systemCharcoal sole plateElectric sole plateMicrowave sole plate

    The future is the most difficult part of this method because we have to propose a new system, i.e., provide a prognosis for the evolution of a new system. We switch from analysis of existing technical system in past and current to building of a new desired future system.

    The future is the most difficult part of this method because we have to propose a new system, i.e., provide a prognosis for the evolution of a new system. We switch to an analysis of a new, desired future system.

    Multi-screen thinking helps develop new proposals for future ironing system with the application-specific rules and an algorithm for thinking through problems and solutions. Among all nine "screens" there are connections that represent interactions between screens and show us directions for thinking. In our analysis, the existing ironing sole plate can be a sub-system, a system or a super-system because it contains other components: the plate itself, electrical spiral, water supply system, etc. Therefore, we can analyze ironing sole plate on different levels.

    Dimensions-Time-Cost Method

    The dimensions-time-cost method requires you to (mentally) experiment with increasing and decreasing dimensions of the system or parameter, shrinking or extending the operating time, and increasing or decreasing cost of the changes to the system. Then the new possibilities are analyzed and some selected for the development of a new system. Let's see how it works by developing new concepts for vacuum cleaning by combining the parameters.

    Note for advanced problem solvers, there are two directions for experiments with this method.

    1. Keep an existing physical principle of operation for all proposals and screens; for example, only focus on the vacuum cleaning principle. This choice is preferable for manufacturing, because it is less expensive and can be implemented quickly.
    2. Develop new physical principles that provide the same function; for example, focus on cleaning generally. This selection is preferred for R&D use.

    The direction depends on the specific situation and customer needs. This article focuses on the second, functional approach.

    The first step is increasing dimensions related to increasing the size of the vacuum from its existing size to infinity. During this thought experiment, we attempt to understand how the problem can be solved at this extreme state.

    Table 2: Dimensions-Time-Cost Method of a Vacuum
    IncreasingStationary slotted sucker under carpetAlways working robot vacuumHome of the future
    DecreasingSelf-cleaning carpetMulti-layer disposable cleaningElectrostatic protection against contaminants

    Dimensions-time-cost analysis helps overcome mental inertia induced by the existing method of vacuum cleaning and to explore new proposals for cleaning systems with appointed steps for thinking. This method with new directions is intended to loosen the existing logical constraints and remove mental restrictions.

    Modeling With Smart Small People

    Modeling with smart small people represents a found conflict in the system. It is depicted as fighting between at least two groups of small people. Drawings should show the resolution of this conflict with the application of available system resources and small people.


    We will consider the application of small smart people modeling with a real example with robotics. There is a robot for automatically cleaning windows. This robot uses two vacuum feet for movement on the window surface. The vacuum under the foot is created by a small-sized vacuum pump (1 – see figure at left). The small-sized vacuum pump (1) can be placed directly on the foot's body (2). The vacuum foot has an elastic seal (3), which connects with a cleaned glass surface (4). A vacuum is generated by the vacuum pump and holds the robot on a cleaned glass surface while its other foot moves from one position to another. If the glass surface has no defects, then the vacuum foot works well. But if there is a defect (5) (crack, orifice, irregularity, etc.), the efficiency of the vacuum foot is reduced because the foot is depressurized by leaking atmospheric air through defect.

    To compensate for leaking and preserving the vacuum under foot, engineers tried to apply a high-power vacuum pump. But the overall dimensions and weight of foot and robot are then increased and the robot's maneuverability and productivity worsen. Then engineers tried another approach by placing the high-power pump not on the foot or the robot's body, but away from the main body – connecting the foot and vacuum pump with additional flexible hoses. The weight and overall dimensions of the robot's mobile parts are improved, but the maneuverability and productivity are worsening because of the long flexible hoses. It was necessary to save an existing vacuum operating method of the robot foot and develop solutions to overcome this problem.




    Let's show atmospheric air particles streaming through a crack in the glass surface like dark small people and vacuum particles on other side of the surface as gray small people. Initially, atmospheric air dark small people run through a crack in a glass's surface and displace vacuum gray small people. Atmospheric air dark small people are much stronger than vacuum gray small people.



    How to eliminate this fight between the groups of small people? Install a barrier between them. There is no direct contact between the two groups and, therefore, the strong atmospheric air dark small people cannot directly interact with weak vacuum gray small people. This idea leads to the next – use a separating diaphragm and segment the foot to make a multi-sectional foot.



    The new design of robot foot (shown at left) has a body (1) made as a frame. Within the frame are numerous vacuum sectional mini-feet (2). Each mini-foot is supplied with elastic diaphragms (3) and is connected by a common vacuum pump. The system is installed on a surface (4) and a vacuum in the chambers of feet is formed. Under the operation of vacuum, elastic deformation of diaphragms occurs.

    The diaphragm's deformation leads to an increase of volume between each diaphragm (3) and surface (4). Therefore, vacuum over diaphragm also creates vacuum under diaphragm. This vacuum leads to the adhesion of the mini-feet to a glass surface.

    The vacuum mini-foot that is placed on crack (5) does not have a vacuum under diaphragm because of leakage. This vacuum foot does not deactivate the rest of the system due to a separating diaphragm. This middle mini-foot on the diagram does not have a harmful influence on the other working vacuum mini-feet. So, depressurization of other vacuum mini-feet does not happen because they are separated from ambient atmospheric air by the diaphragm and the whole foot continues to operate reliably.

    Modeling with smart small people assists with the development of a new scheme of operation principle of vacuum foot on a micro-level and to develop the new design concept with new functional ability. This method is also intended to beat former notions about the existing system and remove previous mental restrictions.

    Methods for overcoming mental inertia can be applied like independent TRIZ tools for solving problems. Modeling with small smart people is included in the structure of ARIZ and is used as part of the algorithm for exploration and application of system resources. Nevertheless, all these methods may be useful on the different stages of the solving process and can be recommended for utilization during analysis of various problems: standard, non-standard and R&D.


    When solving an inventive problem an engineer with a field of expertise will predominantly look for previously known solutions in that field. These solutions and his own experience prevent him from looking at the problem with a new point of view. To overcome this obstacle, psychological or mental inertia, TRIZ supplies special tools. These methods may be helpful during the problem solving process, because they allow you to view the problem from a new perspective. Such an approach can give you a broader view of some concepts and lead to a wider explanation for them. Systematic training with these methods will lead you to view objects, processes and concepts from different sides and develop new stronger innovations.

    Practical Work


    Which mental inertia-overcoming tool can be used in the processes described below?


    The springtime is a pleasant season after the cold winter. We can enjoy the budding trees and blooming flowers with only mosquitoes to disturb us. These small harmful creatures annoy us and we do not want to spend more time in the backyard in the evening. Somebody suggests using sprays, candles or bug zappers, but these are not inspired ideas.


    Scientists have genetically engineered a new plant that naturally repels mosquitoes. It is a plant that grows lush and lovely with minimal care. This plant lets you sleep in peace without waking up bitten. You can put several of these plants around your yard for mosquito-free fun. It is less expensive than candles and sprays and requires no human action.


    When it is raining, it is less fun to drive. Even when windshield wipers help our view through the windshield, side windows lose transparency and do not give us a clear view of outside traffic. Our safety decreases.


    A new product to keep windshields clean and dry employs nanotechnologies in its formula. The household treatment, Nanoprotect Automotive Glass, repels water and keeps dirt from collecting on windshields and windows, and is a svelte 20 nm, which is between 500 and 25,000 times thinner than silicon-based substances. On a windshield the lifetime is up to 50,000 kilometers (over 30,000 miles) and on car windows, not pointing in the driving direction, the product provides its hydrophobic properties for more than five years.

    Three Home Problems


    Saving Gas

    This is a typical problem in the kitchen. How to save gas energy on your stove top and at also cook food faster, simply? Can you recognize a "cool" contradiction in this question? We can try to solve this contradiction, and eventually the gas saving problem, by applying the above discussed methods.



    It is amazing how easily your car can pick up small dents and dings, but they can be costly to repair. So, we may be seriously upset when a minor dent appears on our car. How can we repair it easily and quickly without damaging the car's paint if we cannot reach to the backside of dent?



    The typical umbrella during a skewed rain with strong wind is more of a disturber than helper. When we try to protect ourselves from the skewed rain with wind and move at the same time, we cannot see everything ahead because of umbrella. If we remove the umbrella from the front, then we can see our way but our protection against the windblown rain is worse.

    About the Author:

    Val Kraev is the chief TRIZ officer of the Technical Innovation Center in Worcester, MA, USA, and has contributed several very valuable case studies to The TRIZ Journal. Contact Val Kraev at kraev (at) or visit

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