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TRIZ and Debono's Six Thinking Hats

By Darrell Mann


The Theory of Inventive Problem Solving (TRIZ) is built on solid technical rather than psychological foundations. Combining TRIZ with psychology-based researcher Edward DeBono’s six thinking hats concept can enhance the power of TRIZ.1 This concept has been integrated into a generic TRIZ-based problem definition and solving procedure.

The premise of the hats concept isthat the human brain works in different modes depending on the task it is performing − the brain mechanisms used when generating new ideas are significantly different to those present when calculating pros and cons of an existing idea. DeBono identified six thought modes relevant during the problem-solving process and identified each mode by a different colored hat. Each color denotes a different thinking mode:

  • White:requiring an objective look at data and information
  • Red:associated with feelings, hunches and intuition
  • Black:associated with caution, judgment, and looking logically at the negative aspects of a problem (often described as the “devil’s advocate”)
  • Yellow:examining the feasibility and benefits of a given situation and looking logically at the positive aspects
  • Green:generatingnew ideas, creative and lateral thinking
  • Blue:associated with the overall control and organization of the thinking processes
Figure 1: Six Thinking Hats
Six Thinking Hats

The hats concept can be integrated into any TRIZ inventive problem solving situation – from the initial assessment to problem- definition and solution. Problem-solvers can conduct the function analysis in two parts: 1) look at the positive functional relationships in a system − operating in white hat mode and2) use the black hat mode to analyze the negative relationships in the system. There is also value in switching between white and green hat modes when resolving contradictions as part of the TRIZ toolkit.

White Hat

When wearing the white hat problem-solvers are taking a non-emotional, objective look at data and information. Problem solvers are most likely to require white hat thinking strategies during the following stages of the TRIZ problem-solving process:

  • During the initial problem assessment and definition phase. Specifically, when conducting the initial function analysis − when problem-solvers are describing how the existing system functions and when examining statements describing the desired end-point for the problem –and understanding the present level of maturity of the system (and its sub-systems’) on respective evolutionary S-curves
  • Having completed an initial problem definition, the problem owner is looking to select the most appropriate TRIZ problem solving tools
  • Defining the ideal final result (IFR) and using the ideality problem solving tool concept to find a physically realizable solution
  • When defining contradictions and using the contradiction matrix or the physical contradiction solution method tools
  • When using a functional knowledge-base
  • When recording generated solutions
  • When assessing and ranking the quality of solutions during the down-select part of the overall process
  • In conjunction with the nine windows tool, throughout the overall problem-definition and -solving process ensuring space and time dimensions are given appropriate attention

Because TRIZ is a systematic creativity tool, the white hat is worn most during TRIZ sessions. The other five hats, however, are vital during the process.

Red Hat

The red hat is worn when a problem-solver needs intuition, feelings and emotions − a gut feeling. The red hat thinking mode may appear to be the complete antithesis of a systematic creativity process, but many people naturally think in a red hat mode. By recognizing this natural tendency it is easier to use red hat thinking strategies positively during the TRIZ problem definition and problem-solving process:

  • The red hat mode is a natural thinking tendency when problem solving. By recognizing this natural tendency problem solvers can use it to their advantage. Include a short period at the beginning of a session or immediately after the initial problem definition phase of brainstorming to record the results of the session, so participants can see their input recorded and know it may be used later in the process.
  • Red hat thinking can reduce psychological inertia if the TRIZ problem solving tools have not produced viable solutions.
  • Red hat thinking can help participants break out of the rut that can occur if they spent too much time in other thinking modes − particularly the white hat mode. Provocations like “spend five minutes thinking about the worst possible means of solving the problem” have generated interesting and viable solutions.

Deploy red hat thinkingsparingly when using TRIZ methods.

Black Hat

Wear the black hat when employing caution and judgment and looking logically at the negative aspects of a situation. The black hat thinking mode is most helpful during the TRIZ process when:

  • Defining the problem and identifying the constraints.
  • Conducting a function/attribute analysis of the problem situation and identifying the harmful, insufficient and excessive functions in the current system. Black and white hat thinking are significantly different and a proper function analysis requires both. The most effective function analysis sessions occur when problem solvers use white and black modes sequentially − white first and then theblack hat upon instruction from a problem facilitator.
  • Conductingsubversion analysis− “How can I destroy this system?”
  • Assessing solution options and determining the relative weaknesses of the solutions under consideration.
  • Answering the question, “Is the chosen solution good enough?”

People are inclined toward accepting and settling on a solution that they think is novel. This is evident when they have successfully broken a contradiction. The bifurcated bicycle seat design is an example of why it is important to wear the black hat at the end of a problem solving session. The idea of bifurcation eliminated the “I want the saddle to be wide and narrow” contradiction, and the company decided this was a good enough solution. If they had worn black hats at this stage, they might haverecognized that the bifurcated seat generated new problems which,had they been solved before launching the new product, might have led to success instead of failure.3

Yellow Hat

Wear the yellow hat when examining the feasibility and benefits of a potential solution or when seeking to logically assess the positive aspects of a given situation. Yellow hat thinking strategies are most likely used during the following TRIZ processes:

  • The initial definition stage of a problem when examining the resources that exist in and around the current system.
  • Assessing solution options and gauging the relative strengths of the solutions under consideration.
  • Whenchallenging the validity of the initially-defined problem constraints.
  • When using the trimming part of the TRIZ toolkit − particularly when asking the questions: “Do I need this function? Can an existing part of the system perform the function for me?Can a resource perform the function?” Some users find that trimming is more successful in white hat mode; the author has had more success getting groups to wear a yellow hat.
  • When using the standard inventive solutions and relating them to the problem situation. Solution triggers like “add a substance” can be too obtuse for some; this is less of a problem if people are specifically asked to be in yellow hat mode.

Green Hat

Wear the green hat when generating new ideas or seeking creativity.Green hat thinking strategies are most common during the following points of the TRIZ process:

  • The initial definition stage − a short period of green hat thinking immediately after the yellow hat search for resources often generates additional ideas. The yellow hat mode is important though and should not be replaced by green.
  • When using TRIZ problem solving tools while translating generic solution triggers − inventive principles, trends of evolution, translation of conceptual solutions from the ideality tool, use of smart little people, size-time-cost, etc. − into specific solutions. Green hat thinking is important.4

Blue Hat

Wear the blue hat when controlling or organizing the overall thinking process. Wear the blue hat when judging “when and where” to put on the other hats. The blue hat is the process organizing hat andis worn almost continuously by the facilitator rather than by membersof theproblem-solving team. There are times, however,when the team may benefit by collectively wearing the blue hat:

  • During a post-session recording of events.
  • Periodically during subversion analysis when ensuring that all failure modes are adequately traced and recorded.
  • When a problem solving team is bogged down in detail it is often useful for the team to shift into blue hat thinking − to zoom out of the details and re-orient tothe overall process.

Putting It All Together

There is no one definitive version of a TRIZ process, and it is not possible to propose an all-encompassing TRIZ process. There are, however, generic steps that are typical to problem solving sessions and require us to shift from one hat to another.

The systematic creativity process consisting of four major steps−problem definition, selecting appropriate solution routes, generating solutions and evaluating and down-selecting. Practitioners can view these steps as a looping process which repeats until a solution is obtained. See Figure 2.

Figure 2: Four Major Systematic Creativity Steps


  • What are the benefits and how will the team recognize them? (white hat)
  • What are the constraints? (black hat followed by yellow)
  • What resources are available? (yellow hat followed by green)
  • Where is the “sore point?” (white hat)
  • What are the functions and attributes contained in the current system? (white hat to define intended functions followed by black hat to identify the harmful, insufficient and excessive functions)
  • How mature is the current system? Where does the system and its sub-systems sit on the current evolutionary S-curves? (white hat)
  • Optional − brainstorm and “car-park” initial solution thoughts (red hat)


  • Determine the most appropriate problem solving techniques for the particular problem (white hat)


There are avariety of options depending on which TRIZ tools are relevant:

  • Ideality (white hat)
  • Knowledge (white hat)
  • Contradictions (white hat to generate and look up contradictions; green hat to translate the generic triggers into specific solutions)
  • Trends (yellow hat followed by green)
  • Trimming (yellow hat, probably followed by green)
  • S-fields (preferably yellow; probably followed by green)
  • Smart little people (SLP)/size-time-cost (STC) (green hat)
  • Subversion analysis (black hat; probably interspersed with periods of blue)


  • Have solutions been generated? If “no,” then re-cast the problem (black hat possibly followed by red, green or blue, probably in that order)
  • If “yes,” then rank the solutions (yellow hat systematically followed by black hat)
  • Deciding where to go next − i.e., around the loop again or finish (white hat, but the facilitator should encourage participants to go into black hat mode one more time if possible)

The above is not definitive, rather it is a measure of the need to shift thinking modes both systematically and regularly during a problem session.


Successful use of TRIZ tools demands that practitioners recognize that the human brain works in distinctly different modes. Edward DeBono’s thinking hats define the main modes of operation. Be aware of the different modes and match the appropriate hat to the appropriate parts of the process.


  1. DeBono, E., Six Thinking Hats, Penguin, 1988.
  2. Mann, D.L., “Towards a Generic Inventive Problem Solving Methodology,” presented at 12th ASME DETC Conference, Maryland, September 2000.
  3. Mann, D.L., “Case Studies in TRIZ: A Comfortable Bicycle Seat,” The TRIZ Journal, December 1998.
  4. Mann, D.L., “The Space Between Many Generic Solutions and My Specific Solution,” The TRIZ Journal, June 2001.

About the Author:

Darrell Mann is an engineer by background, having spent 15 years working at Rolls-Royce in various long-term R&D related positions, and ultimately becoming responsible for the company’s long-term future engine strategy. He left the company in 1996 to help set up a high technology company before entering a program of systematic innovation and creativity research at the University of Bath. He first started using TRIZ in 1992, and by the time he left Rolls-Royce had generated over a dozen patents and patent applications. In 1998 he started teaching TRIZ and related methods to both technical and business audiences, and to date has given courses to more than 3,000 delegates across a broad spectrum of industries and disciplines. He continues to actively use, teach and research systematic innovation techniques and is author of the best selling book series Hands-On Systematic Innovation. Contact Darrell Mann at darrell.mann (at) or visit