The Double Diamond is one of the best-known visual models of the design process. Developed by the UK Design Council, it helps teams understand when to explore a problem broadly and when to narrow their focus and make decisions.
Its four phases are:
Discover → Define → Develop → Deliver
What makes the model particularly useful is not simply the four phases, but the movement between divergent and convergent thinking that happens twice during the process.
The Design Council, formerly the Council of Industrial Design, is a United Kingdom charity incorporated by Royal Charter. Its stated mission is “to champion great design that improves lives and makes things better”. It was instrumental in the promoting of the concept of inclusive design.
Every design specialism has a different approach and ways of working, but there are some commonalities to the creative process. At the Design Council, we like to illustrate this with our Double Diamond model, part of our Framework for Innovation.
designcouncil.org.uk
What Is the Double Diamond?
The Double Diamond is a visual representation of the design and innovation process developed by the UK Design Council.
The first diamond focuses on understanding and defining the right problem.
The second diamond focuses on developing and delivering the right solution.
This distinction is important. Teams often begin solving a problem before they have understood whether they are solving the right one.
The Double Diamond deliberately creates space for exploration before decisions are made.
Good design is essential to good business. It turns new ideas into practical products, environments, and services around the changing needs of users.
designcouncil.org.uk
Why Is It Called the Double Diamond?
The shape represents two cycles of expanding and narrowing thinking.
In the first diamond, the team starts with a challenge and diverges by exploring the problem from different perspectives. It then converges by making sense of what it has learned and defining a clearer problem.
In the second diamond, the team diverges again by exploring multiple possible solutions. Finally, it converges by testing, refining and selecting what should move forward.
In simple terms:
Explore the problem → Define the problem → Explore solutions → Deliver a solution
The Four Phases of the Double Diamond
The main feature of the Double Diamond is its emphasis on the “divergent” and “convergent thinking”, where first many ideas are created, before refining and narrowing down to the best idea. This is happening twice in this model—once to confirm the problem definition and once to create the solution.
1. Discover
The Discover phase is about understanding the problem rather than assuming that you already know what it is.
Teams research the context, talk to people affected by the problem, observe behavior and collect different perspectives.
Typical activities may include:
- user interviews;
- observation;
- journey mapping;
- stakeholder interviews;
- desk research;
- analyzing existing data.
The goal is to broaden your understanding before deciding what matters most.
2. Define
During Define, the team makes sense of what was discovered.
Patterns, needs and insights are identified and the broad challenge is narrowed into a clearer problem worth solving.
A useful outcome is a concise problem statement or design brief.
The key question becomes:
What is the real problem we should solve?
This is the first convergence point of the Double Diamond.
3. Develop
Once the problem is clearly framed, the process expands again.
During Develop, teams explore multiple possible answers rather than immediately committing to the first solution.
Activities can include:
- brainstorming;
- co-design;
- sketching;
- concept development;
- prototyping;
- experimentation.
The objective is not simply to generate more ideas. It is to create different possibilities that can be compared and tested.
4. Deliver
During Deliver, promising solutions are tested, improved and narrowed down.
Weak ideas may be rejected. Stronger ideas are refined through feedback and repeated testing.
Eventually, the team moves toward a solution that can be implemented or launched.
Deliver therefore does not simply mean:
Build the idea.
It means:
Test → learn → improve → decide what deserves to be delivered.
Divergent and Convergent Thinking
The central idea behind the Double Diamond is the repeated movement between two different ways of thinking.
Divergent thinking expands the number of possibilities.
You ask:
- What might be happening?
- What have we not considered?
- Who else should we talk to?
- What other solutions are possible?
Convergent thinking reduces possibilities using evidence and judgment.
You ask:
- What matters most?
- What patterns can we see?
- Which problem should we solve?
- Which solution deserves further investment?
The Double Diamond uses both.
First:
Discover broadly → Define narrowly
Then:
Develop broadly → Deliver narrowly
This prevents teams from converging on both the problem and the solution too early.
Double Diamond Example
Imagine that a company receives too many internal IT support tickets.
The initial assumption might be:
We need to automate more support requests.
Discover
The team observes employees, reviews tickets and interviews users.
They discover that many requests are created because employees cannot tell whether an issue should be solved through self-service, a support ticket or another team.
Define
The challenge changes from:
How can we automate more tickets?
to:
How might we help employees quickly identify the correct way to get support?
Develop
The team explores several solutions:
- clearer support categories;
- a decision tree;
- contextual help;
- better search;
- an AI assistant;
- proactive guidance inside applications.
Several simple prototypes are created and tested.
Deliver
Testing shows that a simple decision tree solves most of the uncertainty without requiring a complex AI implementation.
The team improves the prototype and deploys it to a larger group.
The important result is not that the team successfully completed four stages.
The important result is that Discover and Define prevented the team from investing in the wrong solution.
Double Diamond vs Stanford Design Thinking
The Double Diamond and Stanford d.school Design Thinking describe many similar activities but organize them differently.
Stanford uses five modes:
Empathize → Define → Ideate → Prototype → Test
The Double Diamond uses four phases:
Discover → Define → Develop → Deliver
Stanford makes activities such as empathy, ideation and prototyping particularly visible.
The Double Diamond makes another pattern especially easy to understand: divergence and convergence happen both when understanding the problem and when developing the solution.
Neither model needs to be considered better.
They provide different visual structures for organizing human-centered problem solving.
For a broader comparison, see Design Thinking Models Compared: Stanford vs IDEO vs IBM vs Double Diamond.
Is the Double Diamond a Linear Process?
No.
Although the diagram appears to move from left to right, the Design Council explicitly describes the process as iterative.
Research may reveal that the original challenge was wrong. Testing may expose a new user need. Early prototypes may even be useful during discovery.
Teams can therefore move backwards, repeat activities and continue learning after a solution has been delivered.
The diamonds provide structure — not an instruction manual that must be followed mechanically.
The Double Diamond Today
The Design Council now places the Double Diamond inside a broader Framework for Innovation. Alongside the four phases, the framework emphasizes putting people first, communicating visually and inclusively, collaborating and co-creating, and continuous iteration.
Resources to pick from designcouncil.org.uk
I was surprised how many articles you may find on the Design Council resource page. I put here some links I found interesting.
