Tool, Object, Product (TOP) Function Analysis
Editor | On 19, Sep 1999
TRIZ Consulting, Inc.
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This paper was presented at TRIZCON99, The First Symposium on TRIZMethodology and Application of Altshuller Institute for TRIZ Studies, March 7-9,1999, Novi, Michigan
Copyright 1999 by TRIZ Consulting, Inc.
Conventional Concept Development in Innovation
Reducing time to market has become imperative in competition, and the technology to generate breakthrough concepts and ideas has become thereal key to success. Engineers recognize the difficulty of the task by failureto further improve a product significantly. Instead, any attempts to improve oneparameter of the product leads to deterioration of another parameter. Havinglimited time, no guide to solve problems in innovation, and, as a result,failing to develop breakthrough solutions, they select trade-off solutions,fearing that a competitor could have a better result. In addition, project teamsare not sure that all problems that are worth solving are revealed andconsidered.
Today to be successful in product development, there is aneed to develop an exhaustive set of concepts comprising all possibledevelopments of the product. This need requires the formulation of allproduct-related problems worth solving and the successful solving of thoseproblems.
The Theory of Inventive Problem Solving
All problems in innovation are unique, so it is not obviousthat a step-by-step guide could be used to solve all of them. Common thinkingaccepts recommendations such as “be creative,” “generate as many ideas aspossible,” “think about your problem all the time,” “hire ‘out-of-the-box’thinkers,” etc.
Recognizing generic types of problems in innovation was thekey to developing the Theory of Inventive Problem Solving. TRIZ(the Russian acronym for the theory) is the knowledge-based, systematic approachto innovation. Developed in the former Soviet Union by Genrich S. Altshuller(1926-1998) and his school, TRIZ methods are drawn from analysis of the mostinnovative inventions in different industries, technologies, and fields ofengineering.
The power of TRIZ is based on utilizing trends inthe evolution of successful products, ways to overcome psychological barriers,and generalization of the ways used to solve problems in the most innovativeinventions.
TRIZ involves a systematic analysis of the system to beimproved and the application of a series of guidelines for problem definition.TRIZ classifies innovative problems and offers corresponding problem-solvingmethods for each class of problem.
TRIZ analysis of the system to be improved includes anintegrated system approach, function analysis, and function modeling. In problemformulation and problem solving, TRIZ aims to maximize utilization of theresources of the product or process, its supersystem, and its environment.
Since Altshuller stopped development of TRIZ, his followershave continued its development. Extensive practice had dictated the need forimproving the effectiveness of revealing problems to solve, integration of TRIZmethods, and their further development.
Altshuller understood the importance of a function approachin problem solving since the earliest days of TRIZ. For example, his concept ofthe Ideal System says that the Ideal System performs its function but does notexist, which means that the Ideal System performs its function for free and withno harm. However, the need for integration of Function Analysis into TRIZ wasrecognized after developing methods to solve generic problems in innovation.
Function analysis plays the key role in problem formulation.This paper describes an advanced development called TOP Function Analysis andits advantages.
Altshuller developed a method and a set of symbols fordescribing generic types of problems and their solutions. The method was calledSubstance-Field Analysis (SFA).
Altshuller’s model of the simplest useful system iscomposed of three elements – the two substances and the field.
Figure 1. Models of the simplest useful system
Figure 2. Models of an incomplete useful system
Figure 3. Model of the simplest system having a harmful action
Althsuller’s Substance-Field Analysis enables you todescribe models of systems to be improved and models of improved systems. A setof 76 most effective generic transitions of models toward models of improvedsystems he called Standard Solutions to Inventive Problems.
Substance-Field Models describe models of the systems ratherthan functions. However, in order to support Function Analysis, you need todescribe models of the functions.
Tool-Object-Product (TOP) Function Analysis
Tool-Object-Product (TOP) Analysis, the next generation ofSubstance-Field Analysis, was developed by Zinovy Royzen in 1989. The simplestuseful function has four components. It has the tool of the function (or thefunction provider), the object of the function (or recipient of the action ofthe tool), the action of the tool at the object, and one more component – theproduct of the function. The useful function of the tool is to obtain theproduct of the function from the object. The action is described by one arrow,which simplifies the model.
Figure 4. Model of a useful function
Figure 5. Model of a harmful function
Very often a useful action also causes an unwanted effect, or an attempt toimprove a function leads to deterioration in another function of the system.Conflicts are the most difficult type of problem in innovation. TRIZ offersmodels to describe any type of conflict.
Figure 6. Model of a conflict
Modeling a function by describing all four components – thetool, the object, the action, and the product – improves understanding of boththe function and the best ways for its improvement.
The following subsections describe some of the advantages ofTOP Function Modeling:
Generic Model of a Function
Neither the tool of the function nor the object of thefunction has to be a substance. TOP Function Modeling allows you to model anyfunction in any system. It is a more generic way to model a function thanSubstance-Field Modeling.
Precise Description of a Function
Desired and unwanted products of the functions of a modeledsystem improve understanding of the system and simplify analysis of the systemresources.
Link Between Functions
Introducing the product of a function into its model providesa very convenient and understandable link between functions. For example, aproduct of the first function can be a tool or an object of a subsequentfunction.
The link between functions is important in understanding notonly a desired performance of a product, but also the chain of unwantedfunctions. Links between functions simplify cause-effect analysis and improvethe process of revealing the cause of a current or potential failure of aproduct.
Increasing Effectiveness of Function Analysis
Function analysis guides you in decomposing the performanceof your product into single functions – both useful and unwanted. The systemapproach guides you in describing the function of the supersystem of yourproduct and interactions between the product and its supersystem. It also guidesyou in analyzing and describing interactions between the product and itssurroundings that are not part of the supersystem. Then a single function can beconsidered separately if it needs improvement.
TRIZ offers five basic function models:
Adequate useful function (may require technological forecast)
Insufficient useful function (requires improvement)
Absent useful function (requires introduction)
Harmful or undesired function (requires elimination)
Unknown undesired function (requires revealing the cause)
Function modeling helps you to understand the system’sperformance, state the set of problems to consider, rank priority of the statedproblems, classify the problems, and determine the TRIZ Methods to be appliedaccording to the following TRIZ Flow Chart.
TRIZ Flow Chart
A Key to Advanced Development of Problem Solving Methods
TOP Function Modeling has allowed further development ofproblem solving methods and their integration:
Ideal Ways is an analytical method made up of the idealdirections for improving a function. Ideal Way 1, for example, guides you instating problems related to the possibility of elimination of the function andits tool. The TOP model of the analyzed useful function provides the possibleways – eliminating the need for the product of the function or eliminating theobject of the function.
TRIZ Conflict Solving Methods include TRIZ StandardTechniques, ARIZ, and Inventive Principles.
TRIZ Standard Techniques is a further improvement of StandardSolutions, developed by Zinovy Royzen. Standard Techniques arestep-by-step guides for applying generic solutions to your problem anddeveloping specific solutions by utilizing the resources of the system, itssupersystem, and its environment.
TRIZ Standard Techniques include:
- Six techniques for direct elimination of a harmful or unwanted function (Direct Ways)
- Seven techniques for indirect elimination of a harmful or unwanted function
- Three techniques for elimination of the consequences of a harmful function
- Three techniques for converting a harmful action into a useful function
(Direct Ways provides a set of generic techniques forpreventing an unwanted function from producing its unwanted product. IndirectWays is a set of generic techniques for eliminating harm form an unwantedproduct.)
These techniques guide you to consider a complete set of thebest approaches to dealing with a situation where an unwanted function isinvolved. This set of best generic approaches leads to an exhaustive set ofconcepts. The ideality of solutions depends on the availability of resources andthe current constrains, which change over time.
Further development of ARIZ and its integration into theprocess of concept development.
Integration of ARIZ and initial function analysis of a systemhas improved conflict definition and eliminated repetition. TOP modelingimproves understanding of the conflict, its opposite versions, the function ofX-resource and its product. One of the most difficult steps in ARIZ -formulation of the physical contradiction – is simplified significantly.Integration of TRIZ Methods allowed reducing the number of steps in ARIZ andimproving its effectiveness.
A Hard Drive Problem
A hard drive has an actuator arm, which can move relative toa magnetic disk that is rotated by an electric motor. At the end of the arm is aread/write head, which can magnetize or sense the magnetic field of the disk.The head is separated from the surface of the disk by airflow generated by therotating disk. The gap between the head and the disk is very small. Any contactbetween the head and the magnetic disk may cause loss of data.
The disk has a landing zone, where the head is positionedwhen the disk is not spinning. The landing zone is an area of the disk where nodata is stored. When the computer is switched on, the disk starts spinning,creating an airflow, which lifts the arm, and creating the required gap. Thenthe arm is moved away from the landing zone to read and write data. When thecomputer is turned off, the arm is returned to the landing zone. Slowing of thespinning disk decreases the airflow supporting the arm. As a result, the armrests on the landing zone.
Applying an external force to the drive (such as moving orknocking the computer), can move the head away from the landing zone and destroydata on the disk. A latching mechanism is used to prevent the arm from movingwhen the computer is not in use. A permanent magnet holds the arm when the headis in the landing zone. When the computer is turned on, the arm has to overcomethe latch magnet in order to move.
Figure 7. A hard drive
The drive needs to be protected against stronger externalforce. This could be achieved by replacing the current latch magnet with astronger one. But the arm would not be able to overcome the force of any magnetstronger than the current one. Thus an attempt to improve the reliability of thehard drive causes deterioration of its performance.
A breakthrough solution is needed to improve the reliabilityof the drive without any deterioration of its performance, while minimizing anyincrease in production costs.
Summary of Functional Analysis
The latching mechanism includes the latch magnet, a plasticholder for the latching magnet, and a screw. The function of the latch magnet isto hold the arm.
The performance of the latch magnet is insufficient accordingto the requirements for a new design.
A stronger latch magnet will hold the arm adequately, but thearm will not be released.
Figure 8. Model of the conflict
Application of Ideal Ways
Ideal Way 1. Eliminate the need for the function of the magnet.
The arm has to be held in order to prevent it from movingwhile the computer is not in use. We need to correct the model of the function.
Problem 1: If the moving arm cannot damage the disk, there isno need for holding the arm.
Problem 2: If the arm cannot be moved by the external force,there is no need for holding the arm. This statement requires analysis of thechain of unwanted actions that causes the unwanted motion of the arm.
Unwanted action: The arm is moved by its pin.
Problem 3: The motion of the pin caused by an external forcehas to be eliminated.
Unwanted action: The pin is moved by the drive case.
Problem 4: The motion of the case caused by an external forcehas to be eliminated.
Unwanted action: The drive case is moved by the computerchassis.
Problem 5: The motion of the chassis caused by an externalforce has to be eliminated.
Ideal Way 2. Replace the latch magnet.
X=an alternative way to hold
The list of resources includes the resources of the latchingmechanism, the drive, and the surroundings. Analysis of the resources revealedthe possibility of replacing the latch magnet. All resources have to be tried asX.
One possibility: The arm carries a voice coil. Interactionbetween the magnetic field created by an electric current through the voice coiland the magnetic field of the voice coil magnets swings the arm around the pin.The latch magnet could be replaced by a much stronger voice coil magnet. In thiscase, there would be no need for the latch magnet, its plastic holder, and thescrew. In mass production of the hard drives, the solution could save a lot ofmoney for the manufacturer.
Another possibility: The external force itself could be usedto hold the arm instead of the latch magnet. The solution looks like a “safetybelt” for the arm.
The requirement to consider alternative ways to hold the armlead to analysis of a variety of locking mechanisms used in differentindustries.
Ideal Way 3. The arm held by a stronger magnet has to bereleased when necessary.
Problem 6: It is necessary to eliminate the unwanted holdingforce of a strong magnet when necessary. There is a conflict:
An Oxidizer Turbopump Problem
An oxidizer turbopump is one of the most complex andexpensive components of a Space Shuttle Class Main Engine (SSCME). It feeds themain combustion chamber with oxygen. The turbine of the oxidizer turbopump isrotated by a high velocity flow of very high temperature oxygen, called GOX (gasoxygen). The turbopump is made of material that resists working temperatureoxygen.
Failure of the oxidizer turbopump can be caused by a dustparticle or other wearing particle in the GOX. Colliding with the hardware, aparticle, having a very high velocity because of the flow of GOX, would increasethe temperature of the hardware in the proximity of the collision to a levelbeyond which its material could not resist the oxygen.
Ignition of the hardware generates more heat and could resultin complete failure of the oxidizer turbopump and, as a result, the completefailure of the whole engine.
Summary of Analysis of the Failure
Problem 1. A particlecollides with hardware (for example, with the turbine blade).
Problem 2. The heated material of the blade does notresist the oxygen.
Figure 10. Analysis of the zone of the harmful action
Analysis of the SSCME
The engine includes a tank with liquid hydrogen, a tank withliquid oxygen (LOX), the main combustion chamber, and the nozzle.
The fuel (liquid hydrogen) passes through a high-pressurefuel turbopump before cooling the main combustion chamber and nozzle. The fuelis vaporized during the cooling process. After cooling, the fuel is splitbetween two preburners.
The preburner of the fuel turbopump is fed by a fuel-richmixture. The preburner produces a high velocity flow of high temperaturehydrogen that rotates the turbine of the fuel turbopump.
The preburner of the oxygen turbopump is fed by anoxygen-rich mixture, composed approximately 98-99% of oxygen. The oxygenturbopump preburner produces a high velocity flow of high temperature oxygenthat rotates the turbine of the oxidizer turbopump.
Figure 10. Simple schematic of SSCME
Summary of Application of Direct Ways
Application of Direct Ways to Problem 1 led to formulation ofthe following approaches to solving the problem.
Try to insulate the blade from the particle.
Try to introduce a field that will prevent the collision (for example, by repelling the particle).
Try to protect the blade by capturing the particle before it reaches the blade.
Try to modify the particle to make it harmless in the case of collision (for example, melt or evaporate the particle).
Try to modify the blade to be nonsensitive to the collision (in other words, so the collision would not increase the temperature of the blade). This approach leads to formulation of the following physical contradiction: the temperature of the blade has to be increased by colliding particles, but the temperature of the blade must not be increased to the point of resisting GOX.
Application of Direct Ways to Problem 2 led to formulation ofthe following approaches to solving the problem.
Try to insulate the heated blade from the GOX. A technology to plate the hardware of the oxidizer turbopump with ceramic is known. This technology was developed in Russia. It is a very expensive technology. In addition, the ceramic plating would increase the weight of the engine. Furthermore, if the ceramic is not strong enough, it could cause engine failure.
Try to modify the GOX. If GOX is replaced by hydrogen, for example, the possibility of burning the hardware will be eliminated completely. This technology is known as a Fuel-Rich Staged Combustion Cycle Engine System. It has another potential for failure if high-temperature hydrogen mixes with the pumped oxygen in the oxidizer turbopump.
Try to reduce the temperature of GOX. The technology reducing the temperature of GOX without any reduction of the power of the oxidizer turbopump is known as a Full-Flow Staged Combustion Cycle Engine System. The power of the turbopump depends on the velocity and mass of the driving flow. In the known technology, all oxygen that is not directed to the fuel turbopump preburner passes through the oxidizer turbopump. Increase of the mass of the driving flow reduces the required velocity, resulting in reduction in the temperature of GOX.
Try to modify the heated blade. Try to increase the resistance of the blade material to oxygen. This is a materials problem. Materials having high resistance to oxygen do not necessarily have strong mechanical strength. Increasing the resistance of the material to oxygen very often causes increase of the weight of the turbopump.
Try to cool the blade to the working temperature, at which it resists oxygen. This raises subsequent problems: how to cool the heated blade and how to keep the temperature of the cooled zone of the blade from falling below the working temperature (otherwise, the performance of the pump would be deteriorated). An obvious resource for cooling the blade is LOX. But using it as a coolant presents some constraints: it is difficult to maintain working temperature by cooling using LOX, and it is difficult to have LOX in the time and place of an accidental collision.
TRIZ requires consideration of all resources, including GOXand the blade itself. From analysis of the simplified schematic of the engine,it is known that GOX is not pure oxygen. GOX includes 1-2% of water vapor as aresult of burning hydrogen. Water vapor is an excellent coolant. It is alreadyat the working temperature and ready to cool the blade down to the workingtemperature. It was necessary to make calculations to determine how much watervapor is required, but the concept does not require any changes in the hardwareof the engine.
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