What is Double diamond?
The double diamond is a design process framework that divides problem-solving into four phases arranged as two connected diamonds: Discover (diverge to understand the problem), Define (converge on the right problem), Develop (diverge to explore solutions), and Deliver (converge on the right solution).
How it works
Developed by the British Design Council in 2005, the model emphasizes that good design requires divergent thinking (generating many possibilities) before convergent thinking (narrowing to the best one), and this pattern applies twice: first to defining the problem and then to solving it. The most common design failure is jumping to solutions before properly understanding the problem, which the first diamond explicitly prevents.
Applied example
A team tasked with reducing hospital readmissions first diverges: interviewing patients, nurses, and caregivers to discover that the real problem is not medical (doctors assumed) but logistical (patients cannot get to follow-up appointments). The second diamond then explores transportation solutions rather than clinical ones.
Why it matters
The double diamond prevents the costly error of solving the wrong problem by structuring alternation between exploration and focus.
