Design thinking refers to creative strategies designers use during the process of designing. It has also been developed as an approach to resolve issues outside of professional design practice, such as in business and social contexts.
The origins of regarding design thinking as a particular approach to creatively solving problems lie in the development of "creativity techniques in the 1950s and the development of new "design methods in the 1960s. "L. Bruce Archer was perhaps the first author to use the term 'design thinking' in his book "Systematic Method for Designers" (1965). The notion of design as a "way of thinking" in "the sciences can be traced to "Herbert A. Simon's 1969 book The Sciences of the Artificial, and in "design engineering to Robert McKim's 1973 book Experiences in Visual Thinking. Bryan Lawson's 1980 book How Designers Think, primarily addressing design in architecture, began a process of generalising the concept of design thinking. A 1982 article by "Nigel Cross on Designerly ways of knowing established some of the intrinsic qualities and abilities of design thinking that also made it relevant in general education and thus for wider audiences. Peter Rowe's 1987 book Design Thinking, which described methods and approaches used by architects and urban planners, was a significant early usage of the term in the design research literature. "Rolf Faste expanded on McKim's work at "Stanford University in the 1980s and 1990s, teaching "design thinking as a method of creative action." Design thinking was adapted for business purposes by Faste's Stanford colleague "David M. Kelley, who founded the design consultancy "IDEO in 1991. "Richard Buchanan's 1992 article "Wicked Problems in Design Thinking" expressed a broader view of design thinking as addressing intractable human concerns through design.
Design thinking is a method for practical, "creative resolution of problems. It is a form of solution-focused thinking with the intent of producing a constructive future result.
Design thinking identifies and investigates both known and ambiguous aspects of the current situation in an effort to discover parameters and alternative solution sets which may lead to one or more satisfactory goals. Because design thinking is "iterative, intermediate "solutions" are potential starting points of alternative paths, allowing for redefinition of the initial problem, in a process of co-evolution of problem and solution.
In 1979 Bryan Lawson published results from an empirical study to investigate the different problem-solving approaches of designers and scientists. He took two groups of students – final year students in architecture and post-graduate science students – and asked them to create one-layer structures from a set of coloured blocks. The perimeter of the structure had to optimize either the red or the blue colour; however, there were unspecified rules governing the placement and relationship of some of the blocks. Lawson found that:
The scientists adopted a technique of trying out a series of designs which used as many different blocks and combinations of blocks as possible as quickly as possible. Thus they tried to maximise the information available to them about the allowed combinations. If they could discover the rule governing which combinations of blocks were allowed they could then search for an arrangement which would optimise the required colour around the layout. [problem-focused] By contrast, the architects selected their blocks in order to achieve the appropriately coloured perimeter. If this proved not to be an acceptable combination, then the next most favourably coloured block combination would be substituted and so on until an acceptable solution was discovered. [solution-focused]— Bryan Lawson, How Designers Think
Unlike analytical thinking, design thinking includes "building up" ideas, with few, or no, limits on breadth during a "brainstorming" phase. This helps reduce fear of failure in the participant(s) and encourages input and participation from a wide variety of sources in the ideation phases. The phrase ""thinking outside the box" has been coined to describe one goal of the brainstorming phase and is encouraged, since this can aid in the discovery of hidden elements and ambiguities in the situation and discovering potentially faulty assumptions.
One version of the design thinking process has seven stages: define, research, ideate, prototype, choose, implement, and learn. Within these seven steps, problems can be framed, the right questions can be asked, more ideas can be created, and the best answers can be chosen. The steps aren't linear; can occur simultaneously and be repeated. A simpler expression of the process is Robert McKim's phrase "Express–Test–Cycle". An alternative five-phase description of the process is described by "Christoph Meinel and Larry Leifer: (re)defining the problem, needfinding and benchmarking, ideating, building, testing.
The path through these process steps is not strictly circular. Meinel and Leifer state: "While the stages are simple enough, the adaptive expertise required to choose the right inflection points and appropriate next stage is a high order intellectual activity that requires practice and is learnable."
Design thinking is especially useful when addressing what "Horst Rittel referred to as "wicked problems, which are ill-defined or tricky (as opposed to wicked in the sense of malicious). With ill-defined problems, both the problem and the solution are unknown at the outset of the problem-solving exercise. This is as opposed to "tame" or "well-defined" problems where the problem is clear, and the solution is available through some technical knowledge.
Christoph Meinel and Larry Leifer, of the HPI-Stanford Design Thinking Program, laid out four principles for the successful implementation of design thinking:
The "a-ha moment" is the moment where there is suddenly a clear forward path. It is the point in the cycle where synthesis and divergent thinking, analysis and convergent thinking, and the nature of the problem all come together and an appropriate resolution has been captured. Prior to this point, the process may seem nebulous, hazy and inexact. At this point, the path forward is so obvious that in retrospect it seems odd that it took so long to recognize it. After this point, the focus becomes more and more clear as the final product or service is constructed.
Design methods and design process are often used interchangeably, but there are significant differences between the two.
"Design methods are techniques, rules, or ways of doing things that someone uses within a design discipline. Methods for design thinking include "interviewing, creating "user profiles, looking at other existing solutions, creating "prototypes, "mind mapping, asking questions like the "five whys, drawing "issue trees (or issue maps), and situational analysis.
Design process is the sequence of phases of actions used in designing. Because of design's parallel and iterative nature, there are many different paths through the phases. This is part of the reason design thinking may seem to be "fuzzy" or "ambiguous" when compared to more analytical methods of science and engineering. For example, Koberg and Bagnall wrote The Universal Traveler in 1972 which presented a circular, seven-step soft systems approach to problem-solving in daily life that can be followed linearly or in feed-back loops. Many other expressions and models of design processes have been proposed. Hugh Dubberly's free e-book How Do You Design: A Compendium of Models summarizes a large number of design process models.
Ill-defined problems often contain higher-order and obscure relationships. Design thinking can address these through the use of "analogies. An understanding of the expected results, or lack of domain-related knowledge for the task, may be developed by correlating different internal representations, such as images, to develop an understanding of the obscure or ill-defined elements of the situation. The process involves several complex cognitive mechanisms, as the design task often has elements in multiple cognitive domains—visual, mathematical, auditory or tactile—requiring the usage of multiple "languages", like "visual thinking.
Conventionally, designers communicate mostly in "visual or object languages. Symbols, signs, and metaphors are used through the medium of sketching, diagrams and technical drawings to translate abstract requirements into concrete objects. The way designers communicate, then, is through understanding this way of coding design requirements in order to produce built products.
As an approach, design thinking taps into innate human capacities that are overlooked by more conventional problem-solving practices. The process is best thought of as a system of overlapping spaces rather than a sequence of orderly steps: inspiration, ideation, and implementation;or alternatively: empathize, define, ideate, prototype and test. Projects may loop back through inspiration, ideation, and implementation more than once as the team refines its ideas and explores new directions. Therefore, design thinking can feel chaotic, but over the life of a project, participants come to see that the process makes sense and achieves results, even though its form differs from the linear, milestone-based processes that organizations typically undertake.
Generally, the design process starts with the inspiration phase: understanding the problem or the opportunity. This understanding can be documented in a brief which includes constraints that gives the project team a framework from which to begin, benchmarks by which they can measure progress, and a set of objectives to be realized—such as price point, available technology, and market segment.
Both Tom and David Kelley have stated that Design Thinking begins with empathy.  Designers should approach users with the goal of understanding their wants and needs, what might make their life easier and more enjoyable and how technology can be useful for them. Empathic design transcends physical ergonomics to include understanding the psychological and emotional needs of people - the way they do things, why and how they think and feel about the world, and what is meaningful to them.
"Ideation is idea generation. Mentally it represents a process of "going wide" in terms of concepts and outcomes. The process is characterized by the alternation of divergent and convergent thinking, typical of design thinking process. To achieve divergent thinking, it is important to have a diverse group of people involved in the process. Multidisciplinary people—architects who have studied psychology, artists with MBAs, or engineers with marketing experience—often demonstrate this quality. They're people with the capacity and the disposition for collaboration across disciplines.
Interdisciplinary teams typically move into a structured "brainstorming process by "thinking outside the box". During this process participants ideas should not be judged and participants should take generative role. Participants are encouraged to come up with as many ideas as possible and to explore new alternatives. Good ideas naturally rise to the top, whereas the bad ones drop off early on. Every member of the team needs to possess a depth of skill that allows him or her to make tangible contributions to the outcome, and to be empathic for people and for disciplines beyond their own. It tends to be expressed as openness, curiosity, optimism, a tendency toward learning through doing, and experimentation. Convergent thinking, on the other hand, allows for zooming and focusing on the different proposals to select the best choice, which permits continuation of the design thinking process to achieve the final goals. After collecting lots of ideas, a team goes through a process of synthesis in which it has to translate ideas into insights that can lead to solutions or opportunities for change. This approach helps multiply options to create choices and different insights about human behavior and define in which direction the process should go on. These might be either visions of new product offerings, or choices among various ways of creating interactive experience.
More choices mean more complexity, which can affect organization's decisions to restrict choices in favour of the obvious and the incremental. Although this tendency may be more efficient in the short run, it tends to make an organization conservative and inflexible in the long run. Divergent thinking is the route, not the obstacle, to innovation, and a way to diverge is to define a mindset of condition in which people are encouraged to produce lots of ideas. The most notable themes fall into three general traits: open-minded collaboration, courage, and conviction. Open minded refers to the concept of being opened and accept new ideas and contributions. Courage is also fundamental because innovative ideas are characterized by a high risk of failure. It permits to face failure, element of high importance in order to improve in the right way. In addition, conviction is the mindset which permits to carry on a process or an idea even if there are constraints or obstacles.
The third space of the design thinking process is implementation, when the best ideas generated during ideation are turned into something concrete. At the core of the implementation process is prototyping: turning ideas into actual products and services that are then tested, iterated, and refined. A prototype helps to gather feedback and improve the idea. Prototypes speed up the process of innovation because they allow one to understand strengths and weaknesses of new solutions. Prototyping is particularly important for products and services destined for the developing world, where the lack of infrastructure, retail chains, communication networks, literacy, and other essential pieces of the system often make it difficult to design new products and services. Prototyping, testing, "failing many times but quickly and cheaply in order to succeed" are different existing methods to test solutions, but the earlier users can give feedbacks, the lower are the costs for the organizations and higher is the level of adaptation of the solution to customer needs.
Although many design fields have been categorized as lying between science and the arts and humanities, design may be seen as its own distinct way of understanding the world, based on solution-based problem solving, problem shaping, synthesis, and appropriateness in the built environment.
One of the first "design science theorists, "John Chris Jones, postulated that design was different than the arts, sciences and mathematics in the 1970s. In response to the question "Is designing an art, a science or a form of mathematics?" Jones responded:
The main point of difference is that of timing. Both artists and scientists operate on the physical world as it exists in the present (whether it is real or symbolic), while mathematicians operate on abstract relationships that are independent of historical time. Designers, on the other hand, are forever bound to treat as real that which exists only in an imagined future and have to specify ways in which the foreseen thing can be made to exist.
Nigel Cross built upon the early work of "Bruce Archer to show the differences between the humanities, the sciences, and design in his paper "Designerly Ways of Knowing". He observed that in the sciences the phenomenon of study centres around the natural world, the appropriate methods being controlled experiment, classification, and analysis. In this culture, objectivity, rationality, neutrality, and a concern for "truth" are most valued. In the humanities, analogy, metaphor, and evaluation serve as methods of study of the human experience. The values of this culture include subjectivity, imagination, commitment, and a concern for "justice". Design, however, concerns itself with the artificial world and uses modeling, pattern-forming, and synthesis to study it. In design, practicality, ingenuity, empathy, and a concern for "appropriateness" are the core values.
Historically, designers tended to be involved only in the later parts of the process of new product development, focusing their attention on the aesthetics and functionality of products. Many businesses and other organisations now realise the utility of embedding design as a productive asset throughout organisational policies and practices, and design thinking has been used to help many different types of business and social organisations to be more constructive and innovative. In the 2000s there was a significant growth of interest in design thinking as a catalyst for gaining competitive advantage within business, but doubts around design thinking as a panacea for success have also been expressed. Designers bring their methods into business either by taking part themselves from the earliest stages of product and service development processes or by training others to use design methods and to build innovative thinking capabilities within organisations.
All forms of professional design education can be assumed to be developing design thinking in students, even if only implicitly, but design thinking is also now explicitly taught in general as well as professional education, across all sectors of education. Design as a subject was introduced into secondary schools' educational curricula in the UK in the 1970s, gradually replacing and/or developing from some of the traditional art and craft subjects, and increasingly linked with technology studies. This development sparked related research studies in both education and design.  
In the K-12 sector, design thinking is used to promote creative thinking, teamwork, and student responsibility for learning. New courses in design thinking have also been introduced at university level, especially where linked with business and innovation studies. A notable early course of this type was introduced at "Stanford University in 2003, the "Hasso Plattner Institute of Design, known as the d.school. It draws students from several Stanford departments, including engineering, medicine, business, law, and education, utilizing the d.school approach to design thinking to develop innovative solutions to problems. Also, the REDLab group, from Stanford's Graduate School of Education, conducts research into design thinking in K-12, secondary, and post-secondary settings.
|pre-1960||The origins of design thinking partially lie in the development of creativity techniques in the 1950s. Harold van Doren published Industrial Design – A Practical Guide to Product Design and Development, which includes discussions of design methods and practices, in 1940. "John E. Arnold began teaching about creativity at MIT in 1951 and began teaching at Stanford in 1957.|
|early 1960s||The first notable books on methods of creativity are published by "William J. J. Gordon (1961) and "Alex Faickney Osborn (1963).
The 1962 Conference on Systematic and Intuitive Methods in Engineering, Industrial Design, Architecture and Communications, London, UK, started interest studying design processes and developing new design methods. 
Books on methods and theories of design in different fields are published by "Morris Asimow (1962) ("engineering), "Christopher Alexander (1964) ("architecture), "L. Bruce Archer (1965) ("industrial design), and "John Chris Jones (1970) ("product and "systems design).
|1965||"L. Bruce Archer argues that design is "not merely a craft-based skill but should be considered a knowledge-based discipline in its own right, with rigorous methodology and research principles incorporated into the design process". He is also perhaps the first author to use the term 'design thinking', in a limited sense, in his book "Systematic Method for Designers", in the comment "Ways have had to be found to incorporate knowledge of ergonomics, cybernetics, marketing and management science into design thinking".|
|1967||Archer develops the relationship of design thinking with management: "The time is rapidly approaching when design decision making and management decision making techniques will have so much in common that the one will become no more than the extension of the other". |
|1969||"Herbert A. Simon, notable for his research in artificial intelligence and cognitive sciences, proposes a "science of design" that would be "a body of intellectually tough, analytic, partly formalizable, partly empirical, teachable doctrine about the design process."|
|1972||Don Koberg and Jim Bagnall pioneer a 'soft systems' design process for dealing with the problems of 'everyday life' in their book The Universal Traveler.|
|1973||Robert McKim publishes Experiences in Visual Thinking, which includes "Express, Test, Cycle" (ETC) as an iterative backbone for design processes.
"Horst Rittel and "Melvin Webber publish "Dilemmas in a General Theory of Planning" showing that design and planning problems are wicked problems as opposed to "tame", single disciplinary, problems of science.
|1979||"L. Bruce Archer extends inquiry into designerly ways of knowing, claiming: "There exists a designerly way of thinking and communicating that is both different from scientific and scholarly ways of thinking and communicating, and as powerful as scientific and scholarly methods of inquiry when applied to its own kinds of problems."
"Design Studies", the first research journal focussing on design processes begins publishing.
|1980s||Systematic engineering design methods are developed, particularly in Germany and Japan. The International Conferences on Engineering Design (ICED) is formed.
In the USA, the "National Science Foundation initiative on design theory and methods led to substantial growth in engineering design methods in the late-1980s. The "American Society of Mechanical Engineers (ASME) launched its series of conferences on design theory and methodology.
The 1980s also sees the rise of "human-centered design and the rise of design-centered business management.
|1980||Bryan Lawson publishes How Designers Think about design cognition in the context of architecture and urban planning.|
|1982||"Nigel Cross publishes "Designerly Ways of Knowing", drawing on design research to develop Archer's concept that "There are things to know, ways of knowing them and ways of finding out about them" that are specific to design, and showing designerly knowing and thinking to have sufficient intrinsic worth to be included as part of general education.|
|1983||"Donald Schön publishes The Reflective Practitioner in which he sought to establish "an epistemology of practice implicit in the artistic, intuitive processes that [design and other] practitioners bring to situations of uncertainty, instability, uniqueness and value conflict."|
|1986||The business management strategy "Six Sigma emerges as a way to streamline the design process for quality control and profit.|
|1987||Peter Rowe publishes Design Thinking, focused on architecture and planning.|
|1988||"Rolf Faste publishes "Ambidextrous Thinking", extending McKim's process of visual thinking to design as a "whole-body way of doing."|
|1991||The first symposium on Research in Design Thinking is held at Delft University, The Netherlands.
"IDEO design consultancy formed by combining three industrial design companies. They are one of the first design companies to showcase their design process, which draws heavily on the "Stanford University curriculum.
|1992||Richard Buchanan's article "Wicked Problems in Design Thinking" is published.
Eugene S. Ferguson's book "Engineering and the Mind's Eye is published.
|1999||Pierre Sachse and Adrian Specker publish the book "Design Thinking" at the Swiss Federal Institute of Technology - ETH Zurich.|
|21st Century||The start of the 21st century brought a significant increase in interest in design thinking as the term becomes popularized in the business press. Books about how to create a more design-focused workplace where innovation can thrive are written for the business sector by "Richard Florida (2002), "Daniel Pink (2006), "Roger Martin (2007), "Malcolm Gladwell (2008), Tim Brown (2009), Thomas Lockwood (2010), Vijay Kumar (2012), Larry Keeley (2013), and Kim Erwin (2014). This shift of design thinking away from the creation of products into the business sector sparked a debate about the hijacking and exploitation of design thinking.|
|2001||The UK based design consultancy firm livework opens up for business on the basis that the design approach should be extended and adapted to tackle the design of services, marking the beginning of the "service design movement.|
|2005||"Stanford University's d.school begins to teach engineering students design thinking as a formal method.|
|2007||"Hasso Plattner Institute for IT Systems Engineering in "Potsdam, Germany establishes a design thinking program.|
|2008||"IIT Institute of Design launches Design Camp, premier executive education program offering frameworks and tools for practicing innovation in a variety of industries.|
|2015||Jenna Leonardo, Katie Kirsch, Rachel H. Chung and Natalya Thakur from "Stanford University's d.school founded Girls Driving for a Difference to teach design thinking to young girls across the United States.|