Double Diamond

Details
Full Name

Double Diamond Design Process Model

Also known as

4Ds Model, Design Council Double Diamond

Core Concepts:

Two Diamonds, Four Phases

Discover → Define → Develop → Deliver. Each diamond is one divergent-convergent cycle. The first diamond explores and frames the problem; the second diamond explores and ships the solution.

Discover (Divergent, Problem Space)

Broad research — interviews, observation, immersion, data analysis. Goal: widen the understanding of what’s actually going on, not jump to causes.

Define (Convergent, Problem Space)

Synthesize findings into a sharp problem statement. The famous slogan: "Are we solving the right problem?" — the diamond ends with a problem worth solving, not a list of features.

Develop (Divergent, Solution Space)

Generate many candidate solutions — sketches, prototypes, co-design workshops. Diverge widely before narrowing; resist solution fixation.

Deliver (Convergent, Solution Space)

Test, refine, ship. The chosen concept is iterated until it’s production-ready; failed candidates are explicitly killed rather than left lingering.

Design the Right Thing, Then Design the Thing Right

The canonical summary. The first diamond addresses "right thing" (problem worth solving); the second addresses "thing right" (solution that works).

Divergent Before Convergent

A hard discipline at every phase. Premature convergence — picking the obvious problem or obvious solution — is the failure mode the model is designed to prevent.

Iteration, Not Waterfall

The diamonds are not strictly linear. Learnings in Develop frequently send the team back to Discover or Define. The 2019 Framework for Innovation update made this explicit.

Mindsets and Principles

The Design Council pairs the four phases with four principles (Put people first, Communicate visually and inclusively, Collaborate and co-create, Iterate, iterate, iterate) — the diamonds without the mindset is just process theater.

Key Proponents

UK Design Council (originally published 2005; expanded as Framework for Innovation in 2019). Built on the divergent-convergent tradition of J.P. Guilford (1956) and Béla H. Bánáthy.

Historical Context

Developed by the Design Council in 2005 after research into how leading design organizations actually worked. The 2019 update reframed it as a system-level innovation framework, adding the principles, key roles, and explicit iteration arrows. Adopted broadly in UX, service design, government innovation (UK GDS, NHS, Danish Mindlab), and design education.

When to Use:

  • Framing UX or service design projects when the team is at risk of jumping to solutions

  • Innovation workshops and design sprints — the diamonds give a shared visual model for sequencing divergent and convergent work

  • Discovery phases of product development when the problem itself is not yet well understood

  • Teaching design thinking — the model is more concrete than abstract "design thinking" because it names the four moves

  • Communicating why a discovery phase is necessary to stakeholders who want to skip straight to delivery

  • Jobs to be Done — sharpens the Define output by reframing customer needs as functional, emotional, and social jobs

  • Problem Space (NVC) — separates needs from strategies; complements the first-diamond discipline of staying in problem space

  • XY Problem — anti-pattern that the first diamond is designed to prevent (solving Y before understanding X)

  • MVP — the Deliver output is often shaped as an MVP to validate the chosen solution against the defined problem