011 min
Why teams need the Double Diamond
A hospital emergency department in the UK, called an A&E, can be a tense place. People wait there, and some become aggressive toward the staff. The UK Department of Health partnered with the Design Council to explore how design could ease that tension.
One answer came quickly. The Design Council notes that a response could have been to install glass screens and security guards. That answer treats violence as something to block. It does not ask why the violence starts.
The project took another order of work. The Design Council commissioned the design firm PearsonLloyd to understand the main areas of frustration and the triggers of violence and aggression. The design work started with understanding, not with a solution.
A team given a problem can easily pick a solution in its first meeting. If that first guess is wrong, the team finds out late, after the money is spent. The Double Diamond describes the other order: learn what the problem is, then choose among solutions. To see how it does that, start with the shape.
022 min
How the two diamonds work
Each diamond in the picture is narrow at its left end, wide in the middle and narrow again at its right end. The width stands for how many options the team keeps open at that moment. A team widens first and narrows second.
Widening is divergent thinking. The team gathers facts, views and ideas, and it holds back from judging them. Narrowing is convergent thinking. The team compares what it has and chooses.
The first diamond works on the problem. It widens to take in what is happening for the people affected, then narrows to one clear statement of the challenge. The second diamond works on the answer. It widens to produce several possible solutions, then narrows to the one that works. The diamonds stand side by side because the problem has to be settled before a solution can be judged.
Why the shape is a diamond
The shape records where each kind of thinking happens. The Design Council team also put small symbols inside each phase. The symbols mark points where a team can return to research, learning, prototyping and testing. The makers called the two equal diamonds a graphic convenience, and they noticed that the simple symmetry made the idea easy to introduce.
Designing the right thing, then the thing right
Anna White, a designer on the team that made the model, gives a short way to remember the split. She describes the first diamond as questioning the brief and defining the problem statement, and she calls that designing the right thing. A brief is the short written statement of what a project must achieve. She calls the second diamond designing the thing right, which means exploring possibilities, iterating, testing and developing.
032 min
The four phases of the Double Diamond
Each diamond holds two phases, one for the widening half and one for the narrowing half.
| Phase | Thinking | The question | What it ends with |
|---|---|---|---|
| Discover | Divergent | What is happening for the people affected? | Research on user needs |
| Define | Convergent | Which part of this matters most? | A design brief |
| Develop | Divergent | What could solve it? | Several solutions, tested and refined |
| Deliver | Convergent | Which solution works? | One solution, ready to launch |
Discover starts by questioning the challenge, not by answering it. The team does research to find user needs. The Design Council lists market research, user research, managing information and design research groups as typical activities. Its guidance also says the team should speak to, and spend time with, the people affected by the issues.
Define makes sense of what Discover found. The team checks how user needs and the problem fit together, and it lines the needs up with the aims of the business. Teams often sort their observations into groups to find patterns, as in affinity diagramming. The phase ends with a design brief that states the challenge in light of those insights.
Develop widens again, this time for answers. The team develops, tests and refines several possible solutions. It works with people from different disciplines and often with the people it designs for, as described in participatory design. The Design Council also asks teams to look for inspiration outside their own field.
Deliver narrows to one answer. The team tests solutions at small scale, rejects those that fail and improves those that work. It then finishes the chosen solution and launches it. Targets, evaluation and feedback loops continue after launch, so the team learns how the solution holds up in real use. Tests with real users, as in usability testing, fit in Develop and in Deliver.
041 min
How the A&E project used the four phases
The A&E project went through the four phases in order. In Discover, PearsonLloyd spent time listening to patients and to the clinicians who worked in the department.
That listening changed the question. The Design Council reports that the Double Diamond approach showed the main problem to be patients' lack of information about events in the department. The challenge moved from stopping aggression to informing people.
In Develop, a multi-disciplinary design team led by PearsonLloyd produced three solutions: the People solution, the Guidance solution and a design toolkit. In Deliver, the Guidance and People solutions were installed and piloted in A&E departments. The result was a programme of on-site signage, called A Better A&E, that guides patients through their time in the department.
Frontier Economics and ESRO evaluated the pilots. After the changes, aggressive behaviour and threatening body language dropped by half. In the same evaluation, 75% of patients said the improved signage reduced their frustration while they waited, and every £1 spent on the design solutions produced £3 in benefits.
052 min
Where the Double Diamond came from
In 2003 the Design Council had no standard way to describe a design process. Richard Eisermann, then its Director of Design and Innovation, asked his team how they would do it.
The team reviewed recent projects that Design Council programmes had shaped and delivered. They mapped the process of each project and compared them for similarities. Over several sessions they reached four phases, and they chose the names Discover, Define, Develop and Deliver because they wanted names that people would remember. The graphic design agency Cartlidge Levene helped shape the diagram. In 2004 the Design Council began to show it at conferences and in presentations.
Eisermann later said his team had not invented the idea from nothing. In his words, they codified it, renamed the steps and popularised it.
Earlier diamonds
Diamond-shaped models of the design process were older than the Council's version. The Council's history says kite-shaped process models appear as far back as the 1960s. It names Herbert Simon, Thomas Marcus, Thomas Maver, Béla Bánáthy, Barry Boehm, Paul Souza and Nigel Cross among researchers whose models used divergence, convergence or cycles.
Eisermann also met the shape in industry. An IDEO engineer, Dave Duncanson, described product development to him as a kite-shaped diagram with a tail of smaller diamonds. At Whirlpool, the management author Gary Hamel used a diamond to frame innovation and even called it the Double Diamond, with different names for the four steps. Popular accounts often credit one person, Bánáthy. The Council's own history lists him as one researcher among several.
The wrong story about eleven companies
A common story says the Council built the model by studying eleven global companies. The Council's own pages say the order was the other way round. The model came first, from the review of its own projects. The study of eleven companies took place in 2007, and the report used the four phases as the frame for its analysis. The Council's pages give 2004 and 2005 for the model itself, so treat the year as the mid-2000s.
061 min
What eleven global companies did with the same four stages
That 2007 study is worth reading for what it shows about the four phases in daily use. The Council interviewed the design heads of eleven leading companies about how a product or service goes from idea to launch. The companies were Alessi, BSkyB, BT, LEGO, Microsoft, Sony, Starbucks, Virgin Atlantic Airways, Whirlpool, Xerox and Yahoo!
Same stages, different names
The companies used their own words. LEGO called the first stage Exploring, Microsoft called it Understand, and Starbucks called it Concept Heights. The Council found a common core under the names. It expected the four main stages to last through change, while the methods and emphases keep shifting.
Watching 200 users
Testing in Develop was sometimes very large. While building Office 2007, Microsoft observed 200 users working with the new interface over more than 400 hours.
A night in a prototype chair
Testing can also be physical. Virgin Atlantic Airways invited frequent fliers to sleep overnight in prototype chairs for its Upper Class Suite.
071 min
Why the Double Diamond is not a straight line
Large tests like these can teach a team something about the problem that it had not seen. The Design Council says plainly that the process is not linear. Organisations often learn more about the underlying problem and are sent back to the beginning. Making and testing very early ideas can be part of Discover itself.
The Council's study agrees. Some discovery takes place in every phase, to take in new information, user needs and changes among competitors as they appear. The study also says the core stages can be expanded or retracted to fit a project and its context. A team may spend most of its time in one phase and little in another.
082 min
Using the Double Diamond on a project
Because the stages flex, the Double Diamond works best as a set of questions to ask, not as a schedule to follow.
- Write the challenge as a problem to understand, not a feature to build.
- In Discover, talk to the people the problem affects and spend time with them before choosing a research method.
- End Define with a written brief that states the challenge in a way the team did not start with.
- In Develop, produce more than one answer, and work with people from other disciplines and with the people affected.
- In Deliver, test at small scale, drop what fails and improve what works.
- At any time, ask which phase the project is in and which kind of thinking, widening or narrowing, it needs now.
How the Design Council uses it
The Council's own history lists several uses. Teams use the diagram to judge what kind of project they have and what approach it needs. They use it to compare several projects by stage and priority. They use it to focus a team at the start of a project, and to check where a project stands. They also use it to help people feel comfortable with going broad and unfocused in the two widening phases.
The wider framework
The Design Council's wider Framework for Innovation adds four principles to the process: put people first, communicate visually and inclusively, collaborate and co-create, and iterate to spot errors early. It also provides a Methods Bank, a collection of design methods grouped as Explore, Shape and Build.
092 min
Where the Double Diamond breaks down
All of this assumes a team can choose where to start, and many teams cannot.
When the decision is already made
Designer Andy Budd argues that in many companies the decision is made before design is involved. By the time an idea reaches the design team, resources are allocated and a launch date may be set. He proposes working with this pattern, which he calls a reverse double diamond. The team first builds the version the company has chosen. It then uses how that version performs after launch as evidence for improving it.
Other limits follow from the same cause. Some projects begin in the middle, when stakeholders already know what they want built. Two full diamonds also take time and money, which a short deadline may not allow.
More than two diamonds
Many published versions of the Double Diamond do not match the original picture. The NextD Journal, a publication on design methods, argues that most versions in use today contain four or five rounds of widening and narrowing, not two. The Council's own diagram has two.
Large, connected problems
Some problems involve people from many disciplines and sectors at once. For major complex challenges of that kind, the Design Council wrote a separate Systemic Design Framework. The Systemic Design Framework keeps the central idea of the Double Diamond, which is divergent and convergent thinking. Its stages are Explore, Reframe, Create and Catalyse. It also names work that sits around the process: setting direction, building connections and relationships, leadership and storytelling, and continuing the work after a project ends.
101 min
Double Diamond vs. nearby concepts
The Double Diamond is often grouped with other design methods, but it sits at a different level.
| Concept | What it is | How it differs from the Double Diamond |
|---|---|---|
| DesignDesign thinking | ||
| ProductDesign sprint | ||
| Not in the library yetFramework for Innovation |
?3 questions
Questions people ask
Can the Double Diamond be used outside design?
Is the Double Diamond free to use?
Who drew the Double Diamond diagram?
§10 sources
Sources
Design Council, "History of the Double Diamond". designcouncil.org.uk
Design Council, "Framework for Innovation". designcouncil.org.uk
Design Council, "Eleven lessons: managing design in eleven global brands: a study of the design process" (2007). designcouncil.org.uk
Design Council, "Find out how we're making our A&Es safer places to work" (2019). designcouncil.org.uk
Show all 10 sourcesShow fewer sources
Design Council, "A&E Design Challenge: Impact Evaluation Summary" (2013). designcouncil.org.uk
Design Council, "A&E Design Challenge: The Project Report" (2011). designcouncil.org.uk
Design Council, "Systemic Design Framework". designcouncil.org.uk
Andy Budd, "Improving The Double Diamond Design Process", Smashing Magazine (2023). smashingmagazine.com
Google Ventures, "The Sprint Book". gv.com
NextD Journal, "Double Diamond Illusions" (2025). nextd.org
