TRIZ Problem Selection and Definition Reinvigorated!

Transcription

1 TRIZ Problem Selection and Definition Reinvigorated! Amir Roggel a, Gregory Frenklach b a Solutions Engine, amir@solutionsengine.com, Israel b Solutions Engine, gregory@solutionsengine.com, Israel Abstract Classical TRIZ provides effective tools to define properly and to resolve contradictions in a system. Identifying and selecting the right problem to solve before defining it right is a crucial prerequisite for success in any system and process improvement with TRIZ. Effective problem selection has been the object of multiple approaches. A background on these methods and their advancement over classical TRIZ is presented. A novel system theory based tool, called Problem Situation Mapping (PSM) was developed in order to overcome some of the existing limitations. PSM object is the right problem to solve, correctly stated, and the right contradiction to solve exposed. PSM integrates several TRIZ thinking approaches creating successfully a system thinking multi-windows based highly instrumental and practical tool. PSM was developed by author (b) [1] and it is a part of I-MUST Innovation process (Innovation - Multilevel Universal System Thinking) [2]. I-MUST is an application of MUST theory [3]. MUST serves as meta-method to develop new methods, improve existing methods, and obtain synergy among different methods. Keywords: Problem selection, Problem defintion, Problem Situation Mapping, PSM, Puzzle Thinking, TRIZ, TOC, Altshuller Matrix. MUST, I-MUST. 1. Background - the challenge of problem selection Even Einstein couldn t find the solution if he had the wrong problem he is quoted as having said that if he had one hour to save the world he would spend fifty-five minutes defining the problem and only five minutes finding the solution. This tells us that the problem is to know what the problem is. Genrich Altshuller has incorporated problem selection steps in ARIZ versions up until ARIZ-85B. ARIZ-77 [4] for example, includes in steps 1.1 to 1.9 twenty eight questions/directions to determine the final goal of the task, check workaround and look for other problem to be solved in order to obtain the end result etc. These questions/directions about the problem situation were removed in ARIZ-85C. Graphical methods have emerged in attempt to model the problem situation: system/process functional modelling by Litvin and Malkin is based on Value Engineering by Miles [5]. Causality modelling was

2 2 developed: Cause Effect Chain analysis to reveal set of key problems by Litvin [6], Root Conflict Analysis+ to elaborate contradiction during causality tree development by Souchkov [7]. All aimed to expose multiple contradictions and opportunities to improve the system, and enable the solver to choose which ones to solve. System approach methods using multi-screen modelling have been developed to enable Zooming-in: author (b) has replaced Time axes of multi-screen with Causality axes and System Components with Undesired Effects (UDEs) as quoted in [1] and [2]. Problem Formulators were developed using system operator modelling by Zlotin et al. [8] and Malkin et al. [9], the former add axes of Cause-Effect and Input-Output to Time and System level axes of classical multi-screen. The latter attaches Cause-effect relation for problem (sub-system) and Input-Output relation for process (system where problem resides). These works and additional works by Darrell Mann [10], Ellen Domb [11] and others provide additional view angles to examine the problem situation. Main Parameter of Value (MPV) by Litvin provides a view angle from customer/market perspective. Problem Situation Mapping (PSM) is a TRIZ multi-screen based modelling method to cross-hair on the key problem area and zoom-in onto the right contradiction to solve. PSM organizes Undesired Effects (UDEs) by causality and problem-level relations, states the problem correctly as a set of five elements, and transforms the UDEs into a contradiction set. These bring the solver to select the right problem and define it right, making it ripe for inventive solution. 1. Problem Situation Mapping (PSM) what is it and how it works PSM is a method based on puzzle thinking : the ability to see the pieces and the big picture simultaneously, and to connect the pieces to one another properly. It provides a multi-screen mapping tool of the problem situation and a moving cross-hair to lock onto the right problem. The horizontal axis of the multi-screen is a causality axis: Cause-Effect relations, the vertical is Problem level axis. All screens are formulated in same format to enable smooth movement of the cross-hair. Each screen includes a UDE, which represents its associated correctly stated problem. Constructing a PSM: A correctly stated problem is formulated as a set of five elements. Centre screen includes the original UDE. This utilizes functional thinking, as seen in equation (1): P Original = {UDE, Element connected to it, Action of element, Object of action, Environment*} (1) The left screen is the cause UDE (UDE West ). The right screen is result UDE (UDE East ). Both elaborated using equation (1). Note (*) that Environment is written for centre screen, optional for others. Moving up the problem level, the solver removes the Element connected to UDE and identifies the new super-system UDE (UDE North ) occurring without this element, as seen in equation (2): P North = {UDE North, Element removed, Action not done, Object not affected, Environment*} (2) Moving down the problem level, the solver keeps current UDE, lists the common method used today to reduce UDE impact and describes the UDE resulting from using this method: UDE South per equation (3) P South = {UDE South of common method, Element connected, element Action, action s Object, Env.*} (3)

3 3 UDEs at corner screens are built in relation to UDE West and UDE East using equations (2), (3) as if we moved cross hair. This model of Problem Situation Map is described graphically in Fig 1. Fig 1. Problem Situation Map with original UDE under cross-hair Selecting and stating the problem: The solver moves the map under the cross-hair according to the algorithm until stopping on the right problem to solve. The solver zooms-in on the problems associated with the original UDE and its neighbours (UDE North and UDE South, UDE West and UDE East ). The elaboration to five-elements set states the problem correctly. Solver determines now a strategy A, B or both considering resources available: A. UDE elimination. B. UDE measurement or detection Template in Fig.2 is used to document the process. (*) environment is filled in centre UDE. Fig 2. Problem Situation Map template for correct problem selection and stating Once the right problem to solve is stated correctly, the solver is ready to next stage of innovation process algorithm: define the problem right - revealing the contradiction. The adjacent UDEs and associated problems would serve as set of resources for the solution.

4 4 Problem Situation Mapping example: Problem original statement: We cannot increase the speed of an aircraft because of the air resistance to the wings. For original Problem Definition the solver fills the five elements of the set: P = {UDE, Element connected to it, Action of element, Object of action, Environment} UDE: air resistance to the wings Element connected with this UDE: the wings Action of this element: support aircraft body Object of the action: aircraft body. Environment: air around the wings In next steps of Problem Situation Mapping example the solver fills the screens adjacent to centre: Each UDE represents its respective 5-elements set problem, for example UDE South represents P South UDE South is created when the original problem (original UDE) is solved with known methods The original UDE is air resistance to the wings. Known method is to decrease the area of the wings, but another UDE appears: we have to increase the take-off speed of our aircraft... The element connected with this UDE is the airport runway, which would become much too long... UDE North is created when by removal of the element connected with the original UDE. When we remove the wings, there is no air resistance to the wings, but now we have a new UDE connected with the non-performance of the function of the wings. UDE West is the reason for the original UDE. As the reason for air resistance to wings relates to the vortex motion of air, caused by the wing surface, the Element, which is connected with this UDE, is the interacting part of the surface of the wings... UDE East is the result if the original UDE is not eliminated. Loss of time due to low aircraft speed. Determining strategy is done for the problem that moved to the centre: UDE Elimination, Measurement/detection or both are the strategies to choose from. Example: mechanical tool wear-out in metal cutting operation is tracked by measuring the motor current. Then the adaptive system machinery centre changes the parameters of the cutting process. However, overheating of the bearings causes incorrect measurement of the tool wear. For UDE elimination we may, for example, prevent the over-heating of the bearings. For UDE measurement we may measure or detect the over-heating of the bearings. Solver selects the problem to solve among correctly stated problems, determine strategy and defines it as a contradiction. 2. Altshuller Matrix revisited A Case Study of using PSM to improve classical method PSM addresses the front end of the problem solving process: problem selection. The better the tool for this stage is, the better the mid stage becomes ( problem definition ) and consequently, the result of the back end stage ( inventive solution generation ).Overall innovation process effectiveness improves. This section presents theory and practice to demonstrate how PSM reinvigorates usage of Altshuller Matrix [12] in the I-MUST Innovation process. The objective is to move smoothly from problem

5 5 selection stage to problem definition stage, where correctly defined problem is formulated as a contradiction. Remember that correctly stated problem is a five-element set, hence stating the problem properly precedes defining it correctly. Solver starts from an original UDE of the original problem and uses PSM process described in Constructing a PSM section above to elaborate 9 UDEs: UDE Original, UDE North,UDE South, UDE East, UDE West, UDE South-West UDE South-East, UDE Northe-West, UDE North-East Each UDE in center row interacts with the one below it and the one above it which are at different problem level. These pairs create six contradictions as described in Fig. 3 Fig 3. Problem Situation Map with pairs of contradictions The solver moves the screen set virtually in half steps to bring the 6 contradictions under the crosshair. For each contradiction a parameters pair is determined using standard Altshuller Matrix parameters: improving and worsening parameters. Example improvement of Test fixture (Jig) for electronic components. The test fixture is used in automatic testing machine, to measure high frequency surface mounted electronic components (couplers, filters etc). Components are measured, and packed or discarded to the defect bin per measurement result. During measurement the components are placed on the springy contacts of the test fixture printed circuit. Printed circuit is a three-layer sandwich - epoxy glass covered from both sides with thin metal layers per diagram in Fig. 4 Fig. 4. Text fixture with device Measure rate is about 5 components per second. The problem is that the printed circuit is very sensitive to strikes during measurement. Metal layers tend to cracks and result in an inaccurate measurement. This

6 6 failure appears after thousands measurements. The expensive test fixture should be removed from the testing machine and repaired. Repair operation requires special equipment, highly qualified repair personnel, takes much time and is very costly. What can be done? A. Developing original UDE set Original UDE: short life of test fixture Element connected with UDE: printed circuit Action of element: contact component mechanically, for electrical path to measure device Object of action: component B. Known method to repair fixture: replace the printed circuit UDE result (UDE East ): repair time too long, printed circuit too expensive. C. Printed circuit mentally removed from UDE North appears: no electrical path between component and measurement device. D. UDE-cause identified UDE West : cracks in metal layers of printed circuit Element connected with UDE: metal layers (of the printed circuit) Action of metal layers: conduct RF signal E. Known method to repair fixture: replace the printed circuit (as above) UDE North-West appears: repair time too long, printed circuit too expensive (as above) F. Metal layers mentally removed from system UDE North appears: there is no RF signal. G. UDE-result UDE East : low measurement reliability Element connected to it: printed circuit Function of printed circuit: connect the component with measurement device. Known method: repair the test fixture and re-measure H. UDE South-east : poor productivity Mentally removing the printed circuit from the system, creates a new UDE I. UDE North-east appears: there is no contact between component and measurement device

7 7 Table 1 summarizes the six contradictions Contradiction UDE to be eliminated # Short life of test fixture There is no contact between component and measurement device Cracks in metal layers of printed circuit There is no RF signal Low measurement 5 reliability There is no contact between 6 component and measurement device Table 1. Six contradictions derived from PSM The known method to eliminate UDE To change the printed circuit Printed circuit To change the printed circuit Metal layers (of the printed circuit) Re-measurement Printed circuit UDE that appears if the known method is used It takes much time and printed circuit is expensive Short life of test fixture It takes much time and printed circuit is expensive Cracks in metal layers of printed circuit Poor productivity Low measurement reliability Table 2 matches these contradictions to Altshuller s Matrix standard parameters Contradiction # Parameter to be improved Parameter worsening Recommended Principles ,10, ,10, ,35,29, ,28,23 Table 2. Six contradictions presented as standard parameters The process to generate solutions continues as done in regular use of Altshuller Matrix Solution idea was generated based on principles 1 and 2: Printed circuit is turned from sandwich of three layers firmly connected to each other into a sandwich with layers that are not connected each other. This design eliminates strains that are causing metal layers cracks due to repeat contact bending during measurement. As result, the test fixture is ten times cheaper, reliable for millions of measurement and easy to repair. PSM used to obtain synergy of methods - TRIZ-TOC In common TOC process, the solver builds a CRT (Current Reality Tree) in order to identify the key problem: the root UDE, which represents the System Constraint. The UDE statement is reversed to create a positive goal for the Cloud or CRD (Conflict Resolution Diagram). Cloud is elaborated from left to right. Solvers do the mental leaps of converting root UDE into Cloud s goal and elaborating the Must requirements/prerequisites.

8 8 Problem Situation Mapping applies "Puzzle thinking" in order to bridge from CRT system constraint into Cloud by revealing set of UDEs near the constraint. These UDEs are connected by cause-effect relations and by problem-level. The conflicting pairs of UDEs are transformed directly into Clouds as in Fig 5. Fig. 5: Generating set of Clouds from CRT root UDE using PSM Transition from CRT to set of Clouds We start from UDE1 - the original UDE that determines a problem (key problem in TOC TP). PSM help us define additional UDEs as described in Construction PSM section. We receive 6 contradictions as described in Altshuller Matrix revisited section. Each one becomes the Must part of a Cloud. Hence we receive 6 Clouds. We determine which of the Clouds need to be solved in order to eliminate the system Constraint, and proceed in regular process of solving Clouds, where further TRIZ synergy applying TRIZ separation principles to the Cloud s conflict improves results. Original CRT building process is accelerated and improved using TRIZ X-factor these processes and further synergy are beyond the scope of this paper.

9 9 40 Principles new classification The paper focuses on problem selection and definition. Additional solution generation tools developed within I-MUST concludes a more effective innovation process based. In MUST there are 5 customization levels: Result, Method, Technology, Means, and Parameters. I-MUST Innovation process translates them into functional levels, in order to connect classic TRIZ tools to the change levels in the problem s five element set. Here is a classification of inventive patterns, the 40 principles, by functional levels : UDE: 8,9,11,13,21,22,25,27,30,34,39 Element: 1,2,3,4,5,6,7,8,13,14,15,17,18,24,25,26,27,29,30,31,32,33,34,35,37,40 Action: 5,9,10,12,13,14,15,16,17,18,19,20,21,24,28,32,36,37,38 Object: 1,2,3,4,5,7,8,10,13,14,15,17,18,24,25,25,26,27,29,31,32,33,34,35,40 Environment: 3, 8,13,15,30,32,35,39 Note: principles that appear in more than one level, consist sub-principles or suggest a change, for example, principle #9 (Prior anti-action) addresses both UDE and Action. This classification takes advantage of Matrix s elegance in a more instrumental manner than regular use. Conclusions/Summary PSM method and tool were developed as part of the I-MUST Innovation process by using MUST metamethod. PSM provides for the problem solving process a new way to select the right problem and define it right and result in more effective innovation process. PSM is capable to serve as a zoomingtool to improve variety of methods and problem solving processes. Three of them were demonstrated in the paper: Altshuller Matrix, Principles classification and TOC-TP process improvement. The authors believe that MUST meta-method brings a new S-Curve in field of problem solving methods. The readers are encouraged to apply PSM approach on any problem solving technique they practice, to improve the process of problem selection and problem definition. References [1] Gregory Frenklach Efficient Use of the System Operator [2] Gregory Frenklach Multi-level Problem Solving [3] Gregory Frenklach Some thoughts about TRIZ feature transfer into other field of human life [4] G. Altshuller. Creativity as an Exact Science. Translated by Anthony Williams. NY. Gordon & Breach Science Publishers, 1988 [5] Techniques of Value Analysis and Engineering Lawrence D. Miles 1961 [6] S. Litvin Tools for Identifying Correct Problems in G3 : ID Methodology 2007 [7] RCA+ Structured Problems and Contradictions Mapping ETRIA Conference TRIZ FUTURE 2005, Graz, Austria, November [8] Zlotin et al. IWB Problem Formulator by Ideation International [9] Malkin et al. TRIZCON2008 Lessons Learned and Observations from a New Method for Teaching TRIZCON 2008 [10] Darrell Mann Hand On Systematic Innovation 2002 [11] Ellen Domb ETRIA Conference seminar 2009 Frankfurt [12] G. Frenklach Effectively Using the Contradiction Matrix