The Overlap between TRIZ and Lean

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The Overlap between TRIZ and Lean
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  The Overlap Between TRIZ and Lean Amanda BlighIME 552: Lean Manufacturing SystemsUniversity of Rhode IslandMarch 23, 2006 1 TRIZ TRIZ (pronounced ‘trees’), the Russian acronym for ‘The Theory of Inventive Problem Solving, is atoolbox of techniques for problem solving. The basis for TRIZ was developed by Genrich Altshuller, a Sovietnaval patent clerk, in the 1950s. As Altshuller was sorting through patents, he noticed that there are only somany ways that problems can be solved and that problems in different industries have been solved in similarways. He sorted through thousands of patents and was able to find that one (or more) of 40 principles couldexplain each of the inventions he saw in these patents. He also noticed that each of these principles resolveda contradiction that had existed in the technologys development (i.e. an item has to be strong but light).Altshuller was able to find 38 possible attributes that could cause contradictions. From these insights, hedeveloped a problem solving technique. The TRIZ problem solving methods consist of a number of differenttools that can be used together or apart for problem solving and failure analysis.Generally, the problem solving process in TRIZ is to take a specific problem, define it, generalize itby finding the contradictions and underlying principles, find examples of how others have solved the con-tradiction or utilized those principles, and finally, apply those general solutions to the particular problem.This process is similar to applying a math formula, such as the quadratic formula, to a specific situation:generalize the problem to use the formula, then take the generalized solution to apply to the particularproblem. 1.1 Defining the Problem Defining the problem is the most important and often the most difficult step, as there are numerousimpediments. First, the situation is often obscured by jargon. Words that are commonly used within anindustry, but arent used elsewhere can suffer from non-uniform definitions and can obscure assumptionsabout the problem or industry. For example, in the toy industry, the term ‘play-pattern’ is commonly usedto describe how a child will play with a toy. This word can vary in meaning depending on the type of toy andthe perspective: on an electronic toy it may mean the flow charts behind the electronics, the way the childinteracts with it or how it is used when the electronics are not activated. To make sure that assumptionsimplicate in jargon (such as only a child will use this item) aren’t obscuring the cause of the problem, jargonshould be removed and replaced with what is actually intended by the use of the word or phrase.Second, it can be difficult to find the actual problem that needs to be solved. While jargon can obscuresome problems, false problems can obscure others. In some cases the wrong problem is addressed. Forexample: if the problem is that the cost is too high, is that due to excessive material, assembly method orother causes? High cost is not the cause of the problem, the reason for the high cost is: are the tolerances tootight, and causing expensive processes to be used, or is our factor of safety too large causing exotic materialsto be used? The real problem must be found and examined, not the effect that is seen at the higher level.In defining the problem, a list of all resources available is made. Resources include physical parts,movements, systems and manpower, but the complete list also includes fields, such as gravity and EMF. The1  breadth of the resource list defines the possible solution space for the problem, so it is important to includeall resources, no matter how minor (excess heat) or common (air).Additionally, at this stage it is important to identify the underlying contradiction that is causing theproblem. For example, does item in question have to be both strong and light at the same time, or does thepart have to be present, but its presence is causing a problem? The contradiction for the problem needs tobe understood at the beginning in order to completely define the issue at hand.Finally, a number of techniques that can help to define the problem and understand the context of thesolution have been developed. One such technique is referred to as a ‘9-Box’ or ’9-Windows’. This techniqueplaces the system that is being worked with the context of its sub and super-systems and in the past andpossible future embodiments of the system in question. The idea is to zoom out of the present context of the system and understand the broader context. Such a technique can bring resources and possibilities intoplay that were not recognized before. Included in the back of this packet is an example of a completed’9-Windows’ exercise from [1].An optional step at this point it to define ideal solution for the problem. If all the rules of physics couldbe ignored, how would the problem be solved? What is standing in the way of achieving that? Could thecircumstances be changed? Are there additional resources that are creating the impediment to ideality? Theideal final result can differ based on the point of view from which it is determined: it can be thought of interms of the consumer, manufacture, supplier, etc. The differences in the ideal can help to determine whatareas of the design are of interest to all, or only to particular people. From this, an understanding of thesituation that is causing the problem, what approaches can be taken to solve and where common interestslie can be gained. 1.2 Generalizing the Problem The problem is generalized by selecting a particular TRIZ problem solving tool to use as a first approach.There are a number of tools to choose from based on the particular situation. Below is an incomplete listof possible TRIZ tools for use in generalizing the problem. Included here are the fundamental tools. Thereare others (substance-field analysis, trends of technical evolution) which are more complicated to use andbeyond the scope of this introduction. 1.2.1 Separation Principles A subset of Altshullers 40 principles are the separation principles. The separation principles are usuallyused first, as they can often quickly propose a solution. As the name states, these principles refer to separationof some quality. There are four separation principles: separations of parts and whole, separation in time,separation in space and separation based upon condition. The principles are meant to inspire solutions.1. Separation of Parts and Whole: Can the actions/parts/systems be broken up into smaller parts? Canseparate actions/parts/systems be combine into one whole?2. Separation in Time: Can the actions/parts/systems that are causing the conflict be separated in time?Can one action happen before or after the other?3. Separation in Space: Can the conflict be resolved by physically moving the actions/parts/systems? Canremoving a separation in space combine actions/parts/systems and remove the conflict (combinationof separation of parts and whole and space)?4. Separation on Condition: Can the actions/parts/systems be treated/handled differently based oninternal or external conditions? 1.2.2 40 Principles The 40 Principles are based on the patterns of development and technology bases that Altshuller foundfrom his patent analysis. These can be used less formally for brainstorming inspiration, or found from2  utilizing the contradiction table (below) to help inspire solutions. A list and definitions of the 40 Principles,summarized from [1], is attached to this package. 1.2.3 Contradiction Table The contradiction table is a TRIZ tool that provides possible solutions for the contradiction that existsin the problem being solved. To use the contradiction table, the problem at hand needs to be defined interms of one or more of the 38 contradictions that are listed in the first column and first row of the table.The desired attribute is found in the first column and the conflicting attribute is found the first row. Eachattribute is then traced down or right to the intersection square. In this square are up to 4 numbers thatcorrespond to the 40 principles that Altshuller found from examining patents.These principles are intended to be used as starting points for inspiration in solving the problem athand and resolving the afflicting conflict. The solver is by no means limited to using only those principles.The principles listed are given based on the frequency of solutions related to those principles resolving theparticular confilict. Computer programs exist that help to inspire by presenting patents that show examplesof the principles. A copy of the contradiction table is attached to this package that was included with [1]. 1.2.4 Reverse TRIZ The Reverse TRIZ technique is often used for failure analysis, but can also be used to discover potentialproblems. This technique asks the problem solver to look at the system that includes the failure and ask thequestion: If I were going to sabotage this system, how would I do it? The idea of this technique is to findthe weak points in the system. For failure analysis, this can expose contradictions of system related to thefailure that aren’t obvious. With the contradictions defined, the separation or 40 principles can be used tohelp resolve the failure. In the design realm, Reverse TRIZ can be used to anticipate and discover problemsthat can occur within systems or products, as the worst-case can quickly be realized and evaluated. 1.2.5 Smart Little People This TRIZ technique asks the problem solver to think of the site of the problem in terms of smart littlepeople. If there were very tiny people at the site of the problem, what would they do to solve it? Wouldthey hold up small boards to prevent contact? Would they jump up and down? Again, this technique isintended to get the problem solver to think about the situation in a different way. By focusing on the microsituation, a new perspective of on the problem can be gained. This technique can be used with the separationprinciples or the 40 principles once the conflict has been identified. 1.2.6 Ideal Final Result Ideality can also be used as a problem solving tool. As explained above, this technique is to think aboutthe perfect result to the problem at hand, disregarding physical and monetary limitations. The ideal finalresult can then be used back out ideas that have similar features to the perfect result. 1.3 Generating Solutions The next step in the process, once a problem solving tool has been chosen is to generate possible solutions.In the outline offered at the beginning, this step includes finding the general solution and using the generalsolution to find a specific solution for the given problem. This is done by applying the tool to the definedproblem, finding general solutions then using the general solutions to list specific solutions.A general solution is a principle that is determined from the contradiction table (as described above), orselected from the separation principles. It could also be the initial ideal final result, or the description of what the smart little people would do. The next step is to make the jump from the general to the specific.It is at this point that knowledge of many industries and technical areas are helpful. For example, if the tool being used is the contradiction table, the result of the contradiction table is a choice of up to3  four of the 40 Principles. Knowledge of other industries can help to discover comparable solutions in otherindustries. Knowing about the segmentation of tank treads, may lead to the application of a similar solutionin a consumer product setting, if the contradiction table had pointed toward the principle of segmentation(there is software that automates this process and can suggest relevant patents to the principles that arebeing investigated).For another example, if the tool used was the ideal final result, and it was determined that the systemwould work perfectly if it weren’t for the presence of UV radiation, maybe the solution is that this systembe only used in a shaded area or at night.Though it still takes some creativity to determine the ultimate solution for a problem, the goal of TRIZis to order how the problem is thought about to help arrive more quickly at the optimal solution. Like anyother tool, the more often it is used, the better the user becomes at judging which solution path will be mosteffective. 2 Overlap Between TRIZ and Lean Ideas TRIZ and lean thinking have many common points. Overall, they are both ways of improving theoperation of a system. TRIZ focuses on individual elements to optimize, where lean takes in the entiresystem to find potential efficiencies. The similarities are not only on the system level. Many TRIZ elementshave a lean counterpart.Both TRIZ and lean take a substantial amount of time to define the problem. In TRIZ it is very importantto understand all of the resources that can be used to solve a problem and to understand where the realproblem lies. This can be done by the ‘9-Window’, as described above, or by other methods. In lean, thegoal is to understand the entire system and how materials and information move through it. To do this, theprimary tool is the current state map. The current state map defines the system in lean terms much like the‘9-Window’ exercise defines the context for a TRIZ problem. Both are used as starting point for a completeunderstanding of the system.Both TRIZ and lean have a desire to move beyond what is currently being understood as the truth. InTRIZ, the problem solver must uncover the assumptions that are made by the use of jargon and currentproblem definition. In lean, a common term is ‘go and see’. This means that it is better when defining thesystem at hand to go and see how it works, not just assume that the information that has already beengathered is correct.TRIZ and lean both look toward the future ideal. TRIZ uses the idea of the ‘perfect’ system to understandwhat is wrong with the current system and why ideality can’t be implemented. Lean uses the future statemap to write down a set of goals to aim for in the lean implementation. Through both systems, the goalis to reach a more ideal state than the current, whether it be a particular problem solution or a plantreorganization.Finally, both TRIZ and lean look to optimize the use of available resources. In lean, the goal is toeliminate waste, as waste means there are inefficiencies and counter-productive actions in the system. InTRIZ often the problem solution utilizes a resource that had previously been seen as a nuisance or as waste.All of these overlapping elements speak to the use of TRIZ ideas in a lean implementation. 3 Using TRIZ in Lean TRIZ can also be a useful addition to lean. TRIZ, as a problem solving technique, can be used withinlean to find methods of accomplishing tasks that may not have otherwise been found. TRIZ lends itself wellto finding solutions that utilize currently available resources that may otherwise be seen as waste (‘muda’in lean). In addition, TRIZ’s ideal final result could help in developing future state maps, by looking at aparticular process and its role in the entire system and determining how ideality for both can be balanced.Finally, in creating the current state map, TRIZ’s problem defining techniques, such as ‘9-Windows’ and4
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