Use of TRIZ in the Development Process - Zero-Defect-Development for Customer Centered Innovative Products

Veit Kohnhauser
Technical University of Vienna
Department of Applied Economics
kohnhauser@ebwnov.tuwien.ac.at 

In today’s business world, successful companies must stand their ground in an extremely competitive environment and must constantly adapt their products to new market demands. At the same time the lifecycle of many products has considerably decreased. If the product has a long pay-off period the enterprise has very little time to make the desired profits. At the time of entering the market, any quality deficits could cause failure and push the enterprise into severe financial crises.

To operate successfully within the area of conflict between cost, deadline and quality, it is not sufficient that all persons involved are aware of this difficulty. Efficient tools allowing a constant fine tuning of the development process must be available to the team. Any product deficits that could cause customer complaints must be eliminated during the development phase as far as possible. Failure detection and failure management are not the customers’ job but must be carried out by the development engineers. To elucidate the strategic importance of such preventive quality planning in early product development phases, some especially relevant examples will be illustrated. Quality must be developed into the product from the very concept. This increases the expenditure at an early stage of the project but ensures that in consequence neither time nor money for the realization of second-or third-class concepts is wasted. The following graphic shows that up to 75% of all mistakes occur in the development stage. For the most part they are eliminated in the production-or testing phase. In particularly disadvantageous cases the faults are only detected by the customers.

One example for this is the callback of the new Opel Astra (Europe, Nov 1998). It was triggered off by consumers’ complaints about scraping noises at steering, which – according to the company’s information – had been caused by tolerance defaults. Late fault management becomes especially perilous when the costs necessary for failure correction are examined. Opel sent 150.000 models to the service station for a half hour inspection. Assuming an hourly rate of 600 ATS, a damage of 45 million ATS is incurred merely from garage stays. For that amount of money 1125 development engineers could calculate tolerance for a whole week. Loss of image and other financial damage are not even taken into consideration in this calculation.

For the development of profitable products it is essential to systematically identify all conceivable problems and potential deficiencies. For that, various methods were worked out to assist the engineer in doing his difficult job. Such, the development process can be effectively supported through adequate methods and tools. In practice it has proved a success to consult experienced moderators who make it possible for the diverse development steps to proceed in a coordinated fashion within an interdisciplinary team.

To all these methods the same rule applies: they must not occur as ends in themselves. There is always a danger that the research team makes it its business to fully complete the given forms and graphics. If the project is backed up with simple calculations, the impression of a scientifically accurate computation arises. It must be the moderator’s job to push the applied method as far as possible into the background and use it merely as a guide and guiding data for his further procedure in problem search. The intellectual potential doesn’t lie in completing forms but rather in discussion and discourse which are necessary to acquire information and must take place within the development team.

The diverse tools accordingly constitute neither new nor additional assignments for the engineers, but help all members of the team to systematically and orderly conduct those tasks which are to be carried out for a successful implementation of the project. Only by such systematic work can the development process be controlled and continually developed.

This contribution exemplary sketches how, starting from the consumer’s demands, innovative products can be systematically developed. Besides it shows how the diverse product parameters are harmonized in an optimal way. The following illustration of a mouse-trap shows how TRIZ can work for the development procedure.

It is inevitable for the realization of efficacious products that the customer demands are identified and understood. Therefore those people who must later process the consumers’ information should be tied up in the procurement of information from the very start. After all they know best what kind of information is essential for developing new products. It is the only way to ensure that by the time of project launch all compulsory data is available and the staff members accept this information. For the registration of customer requests diverse information channels can be tapped:

It is the development team’s task to translate customer demands into actual product characteristics. This performance can be assisted by QFD. The QFD is accomplished in interdisciplinary teams, which guarantees the integration of all concerned departments from the beginning. Intense discussions occasion all project members to think about what the product must look like to transform customer demands as good as possible.

It must also be noted that the consumer requests meet the current situation. The KANO – model shows how those product characteristics that enthuse the customer today will tomorrow be taken for granted.

In the mouse-trap example following customer demands could exist:

The development team’s effort now lies in converting these consumer demands into the technical characteristics of the mouse trap. In a next step the degree of the customer demands’ realization that can be achieved with the technical parameter is rated. For the mouse-trap following characteristics were derived:

When constructing a mouse-trap that meets all customer demands it appears that some parameters affect each other negatively. E.g. the customers want the trap to be safe in handling and quick in killing the mouse. To kill the mouse immediately the trap needs as much striking force as possible. But an increase in drive also raises potential hand injuries.

So there are two customer demands "safe for fingers" and "kill immediately" which are hardly compatible. The ranking indicates, though, that the realization of both requirements is of high relevance to the customer. At the same time the QFD shows how our competitors are rated and maybe we realize we must improve. The calculated ranking of the separate technical parameters signals that the striking force is of high significance to the product.

The main question for the development team is: "How do we produce a mouse trap which kills quickly and is at the same time safe for the user?"

This simple example illustrates that the QFD comes in handy to identify problems. Its main advantage is that a direct correlation between the identified problem and the customer demands can be established. The question whether a problem is relevant to the consumer can clearly be answered.

TRIZ for the first time enables development engineers to systematically solve the identified problems. This enlarges the expenditure for the development of new concepts, but it also ensures that all potential solution possibilities are taken into consideration. Hence the best concept will be realized. TRIZ consists of several different tools that can be used to solve technical problems. There is no fixed order which must be followed in the problem solving process. Rather, the TRIZ users’ knowledge and experience direct what tools are to be used in connection with the particular problem.

In the above example the problem was handled with the "40 principles" to solve technical conflicts. A conflict is given when the improvement of one parameter leads to deterioration of another parameter. In our case, the "user friendliness" decreases as the "striking force" increases. For this conflict TRIZ offers so called solving principles that can be drawn from the conflict-matrix. For our problem following principles were set out:

• grouping/ segmentation (1)
• Replace mechanical systems (28)
• Local characteristic (3)
• Self-sufficiency (25)

Each of these principles must be worked over to develop adequate concepts.

TRIZ suggests, e.g., to apply the "grouping/segmentation" principle to the mouse-trap. It advises to split the trap into several parts. This means as follows: a special holding device is constructed which cuts out the risk of finger injury during the commissioning of the trap. Is the trap ready, it is set and the holding device is removed. A further principle is the replacement of mechanical systems with an optical, acoustic, or electric field. In the mouse-trap example, electroshock could serve as a substitute for the mechanic guillotine in killing the mouse.

All solution possibilities given by TRIZ must be examined step by step, till all imaginable solution concepts are elaborated. If the acquired solutions are non-satisfactory, further TRIZ tools must be applied. The preceding QFD guarantees that those problems which hinder the realization of customer demands are treated first.

To not only satisfy the customers but also enthuse them with product innovations it is not enough to simply fulfill the set demands. TRIZ offers the possibility to simulate future developments of technical systems. The basis for this is the classical s-curve model. Previous experience was used to derive laws of evolution of technical systems. By means of these laws scenarios on how the mouse-trap will further be developed can be worked out. TRIZ promotes the system evolution but nobody knows how big the market will be and when the product will have reached the forecast development stage. That requires the methods and techniques of modern marketing. Yet it is of great advantage to many companies to predict what the future product, fulfilling the same functions as the already existent product, might look like. The development of new product concepts by means of these regulations of dynamism can be illustrated by the following example. [Source: TechOptimizer™]

Here is a list of the mouse trap concepts that these examples of the technology forecasting pattern of "Flexibility" suggest. The basic function of the mousetrap is "killing the mouse". This function is performed by the guillotine:

a rigid guillotine kills the mouse a guillotine with a joint kills the mouse a flexible guillotine kills the mouse a liquid or gas kills the mouse an electrical field kills the mouse

After deciding in favor of one distinct solution concept all conceivable shortcomings that occur with the realization must be given thought. For that, an FMEA can be made. The potential shortcomings are assigned to the corresponding causes of fault. TRIZ assists this search for causes of fault by means of the so-called "subversive failure analysis". Here a little trick is used.

The potential deficiency is defined as desired event. This is to be attained by means as simple as possible.

A potential weakness in the mouse-trap case could be that the mouse gets the bait without setting off the trap. To eliminate this deficiency it is essential to know all causes for the failure. How does the mouse manage to steal the cheese? For subversive failure analysis the problem must be inverted. The idea is formed that the mouse-trap holds a valuable diamond instead of cheese. The task now is to get the diamond without triggering the trap off.

This is one problem like many others. TRIZ is a means to reach for solutions. Each solution found constitutes a potential cause for failure.

For the mouse trap there could be the following solutions:

• the mouse can touch the mousetrap in such a way that the trigger is activated, but the mouse itself is not in the "right" position.
• the mouse fixes the mousetrap with one of it’s paws so that the bait can’t move down.
• the mouse waits until corrosion fixes the mousetrap...

With all potential failures to the developed concept identified and eliminated, the optimization of the product parameters should be carried out prior to series production. Especially with substantial changes at the product the risk of unwelcome side-effects which were not sufficiently reflected occurs.

The mouse-trap example shows how optimization can be achieved by simple means. In the past, more or less complicated mathematical methods were developed that had to be applied to this problem. Nowadays, practical industry solutions developed, which replace statistics by graphs to a great extent. Now, even "non-statisticians" can apply these optimizing processes. Simple calculations on mean and mean variation are sufficient to achieve good results.

Thereby, main effects and interaction effects are distinguished. Main effects indicate how changes of separate parameters influence the result. One examination could for instance be the effect of 2 differing sorts of bait on the amount of mice caught. To optimize the parameters it is especially significant to consider not only the main effects but also the corresponding interactions between the parameters. An interaction for two factors is given when one factor’s influence on the target size depends on the adjustment of other factors. In the above example this means that along with the optimization of the length of the guillotine it is necessary to consider the spring strength used and the size of the base-plate.

For this the development team works out those parameters that are being optimized in the course of test planning. In the mentioned case following 4 factors were chosen:

• Length of guillotine
• Spring strength
• Bait
• Base-plate

For each of these parameters two levels were determined which served the parameter optimizing.

Since the bait does in no way interact with the other parameters, an experimental plan can be made. The – and + symbolize the respective parameter adjustments. The number of mice caught per week is target size Y.

In this case 8 tests were done. The last column shows the number of mice caught for each combination of parameters. This chart can easily be analyzed graphically.

To find out whether bacon or cheese is more suitable to catch mice, following calculation must be accomplished.

The sum of all K (13) divided by the number of tests (4) amounts to the average number of mice caught with cheese (3.25). Then, the average number of mice caught with bacon is calculated and entered to the diagram. Next, the two points are connected. In the above case an average of 3.25 mice were caught with cheese and 3.75 with bacon. Bacon is the better bait to catch mice.

To enable the consideration of the interaction between parameters they must be converted into a graphic as well. The calculation pattern is exactly the same as before. To work out point F+B+, the average for caught mice is formed from the respective combinations of parameters. The average (3.5) of test 1 and 2 is computed.

Concerning the relation between guillotine and spring strength the diagram clarifies that with a long guillotine the springiness doesn’t affect the number of caught mice, whereas in combination with a short guillotine more strength is advantageous. The graphic of all parameters and their interaction allows a fast and simple analysis of the series of tests. In the above example the decision was made in favor of long guillotine, high spring strength and base-plate B. Bacon is the preferable bait.

In this way, all other parameters of the mouse-trap can be evaluated. This process leads to optimal performance of the mouse-trap even before series production starts. It might happen, of course, that new problems occur with the test run. These problems must again be properly described and consequently worked on by TRIZ.

It must be the aim of any product development to meet customer demands in an optimal way and, if so possible, exceed consumer expectations by means of product innovations. Only with such innovations a company can achieve profit on the market in the long term.

Having innovative ideas is not enough, though. They must also be converted into new products suitable for customers. It is to be considered that with a great amount of changes there is a risk to get new, so far unknown failures.

Merely by systematic failure finding deficiencies can be identified and eliminated in time. All members of the team must bear in mind that the major part of failures occur in the early development phase and their elimination at a later project phase causes enormous costs.

TRIZ helps development engineers to overcome psychological barriers in the concept phase. It is here that the course must be set and the most promising way must be found. Once traveling a mediocre way, even with highest efforts the project’s success can only slightly be increase

With TRIZ, though, all imaginable ways for the solution of a problem are surveyed. The development engineer obtains a complete map of all possible paths of solutions. The team must decide in collaboration with the distinct experts which way is the favorable one for the company. Even if at first glance it seems as if it were impossible to let a creative process run systematic or software supported, a closer examination shows that TRIZ forces the development engineers to exactly define the problem and deal with all areas of solution. TRIZ cannot generate a solution, but it leads to specific formulations of questions, and makes the team find suitable answers to these specific questions. This means for TRIZ users:

1. Taschenbuch Versuchsplanung", Wilhelm Kleppmann; hanser 1998
2. Taschenbuch Qualitätsmanagement", F.J. Brunner / K. Wagner, hanser 1997
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4. "The science of innovation: a managerial overview of the TRIZ methodology", Fey Victor – Southfield, Mich.: TRIZ Group, 1997.
5. "Step-by-Step TRIZ: creating innovative solution concepts", Terninko Zusmann, Zlotin:; - 3. ed. – Nottingham, NH: Responsible Management, 1996
6. "TRIZ – der Weg zum konkurrenzlosen Erfolgsprodukt: Ideen produzieren, Nischen besetzen, Märkte gewinnen." , Terninko, Zusmann, Zlotin (Hrsg. Herb): Landsberg am Lech: Verl. Moderne Industrie, 1998
7. "Versuchsplanung: der Weg zur Qualität des Jahres 2000", Krottmaier Johannes, Zürich, Verlag Ind. Org., 1991
8. "Kundenorientierung durch quality function deployment", Saatweber Jutta:: München: hanser verlag: 1997
9. "QFD Quality Function Deployment", Yoji Akao, Landsberg / Lech, Verlag moderne industrie, 1992
10. "F&E-Management", Specht Günther, , Stuttgart, Schäffer-Poeschel-Verlag, 1996

Dipl.Ing. Veit Kohnhauser, born in 1972. 1997 degree in ECONOMY ENGINEERING (WIRTSCHAFTSINGENEURWESEN) – mechanical engineering at the University of technology Vienna; since 1997 assistant professor at the Department of Industrial Engineering, Ergonomics, Applied Economics (IBAB); since 1998 lector at university for applied science for "Automation- and Production- Engineering"; assessor of "AFQM" for the award of the "Austrian Quality Awards" (AQA);

Department of Applied Economics
Technical University Vienna
Theresianumgasse 27
A-1040 Vienna
Phone: 0043-1-58801-33043
Fax: 0043-1-58801-33094
Email: kohnhauser@ebwnov.tuwien.ac.at