The Double Diamond Design Process Explained

The Double Diamond is a design process model, developed by the UK Design Council, that structures problem-solving into four phases across two cycles of "diverging" (exploring broadly) and "converging" (narrowing down to a decision): Discover, Define, Develop, and Deliver. The name comes from the shape formed when you draw these four phases — two diamonds side by side, each widening out then narrowing back in.

Quick facts

• The four phases: Discover (explore the problem broadly), Define (narrow to a specific problem statement), Develop (explore solution ideas broadly), Deliver (narrow to a specific solution and build it).
• The core discipline is deliberately separating "exploring broadly" (diverging) from "narrowing down" (converging), rather than jumping straight to one idea.
• The first diamond focuses on understanding the right problem; the second diamond focuses on finding the right solution to that problem.
• Developed by the UK Design Council and widely adopted across design and product teams.

The four phases, explained

Why the "diverge then converge" pattern matters

A common mistake in problem-solving is narrowing down too quickly — jumping to the first plausible solution before genuinely exploring the problem or considering alternative approaches. The Double Diamond's explicit structure forces two distinct rounds of broad exploration before narrowing to a decision: first broadly understanding the problem before committing to a specific problem statement, then broadly generating solution ideas before committing to a specific solution. This deliberate discipline tends to produce better outcomes than skipping straight from "here's a rough problem" to "here's our solution," since it reduces the risk of solving the wrong problem, or missing a better solution that wasn't the first idea considered.

A worked example: redesigning a checkout flow

Discover: The team researches broadly — reviewing analytics, watching session recordings, talking to customers who abandoned checkout — without yet committing to what the specific problem is.

Define: From that research, the team converges on a specific problem statement: "Customers abandon checkout most often when unexpected shipping costs appear on the final step."

Develop: The team broadly generates solution ideas: showing shipping costs earlier in the flow, offering a flat-rate shipping option, adding a progress indicator so users know what's coming, and a few other possibilities.

Deliver: The team narrows to the most promising solution — showing shipping costs earlier — refines it through prototyping and testing, and builds the final version.

Each phase has a clear purpose, and the explicit diverge-then-converge structure at both the problem and solution stages helps ensure the team didn't just solve the first problem that seemed obvious, or build the first solution idea that came to mind.

How Double Diamond relates to Design Thinking

The Double Diamond shares real conceptual overlap with Design Thinking — both emphasize deeply understanding a problem before jumping to solutions, and both value generating multiple ideas before converging on one. Double Diamond is often described as a simpler, more visually memorable structure (just four phases across two diamonds), while Design Thinking typically includes more specific named stages (Empathize, Define, Ideate, Prototype, Test) with a stronger emphasis on rapid prototyping and testing within the process itself.

Common mistakes when applying Double Diamond

• Skipping the Discover phase and starting directly at Define, assuming the problem is already well understood without genuine research. This risks solving a problem that isn't actually the right one.
• Not genuinely diverging during Develop, and instead generating just one solution idea and calling it done. The value of this phase comes specifically from considering a real range of options.
• Treating the four phases as strictly linear with no return. In practice, teams sometimes need to revisit an earlier phase (like returning to Discover) if the Define or Develop phases reveal a gap in understanding — treating the process as too rigid can prevent this useful iteration.
• Rushing through Discover and Develop to get to a solution faster. The time invested in genuine divergence at both stages is what differentiates this process from simply jumping to the first idea.

FAQ

Who created the Double Diamond framework? The UK Design Council developed it, and it has since become one of the most widely referenced design process models across design and product teams internationally.

Is Double Diamond only for visual/UX design work? While it originated in design practice, its underlying diverge-then-converge structure applies to a broader range of problem-solving contexts, including general product strategy and even business problem-solving beyond visual design specifically.

How long does a full Double Diamond process typically take? It varies enormously by the scope of the problem — a small feature redesign might move through all four phases in a couple of weeks, while a major strategic initiative could take months, especially if the Discover phase requires extensive research.

Can Double Diamond be used within an Agile/Scrum workflow? Yes — many teams use Double Diamond-style thinking for discovery work that happens before or alongside sprint execution, treating it as a discovery framework that feeds into a more traditional Agile delivery process rather than replacing it.