What needs to be finished first
A rough problem space or intake brief with stakeholder expectations and constraints exists as a starting point for the Discover phase.
What needs to be ready before start
Project plan with four phase slots (Discover, Define, Develop, Deliver); research toolkit (interview guide, templates, recorder); synthesis wall or Miro board; prototyping tools; tracking tool for findings and decisions.
Lead designer or service designer; one to three researchers; cross-functional core team (PM, engineering, design); stakeholder reviewer at each diamond transition; sponsor with mandate across diamonds.
Intake brief; stakeholder map; known constraints (time, budget, technology); research questions; existing data and prior work; desired deliverable at phase end.
Weeks to months
Visualize phases as diamonds on wall or board. Define done criteria per phase (what must be at transition). Schedule transitions with stakeholder reviews. Prepare synthesis rooms.
The one question this method answers
What framed problem and what implemented solution does the team deliver through deliberate divergence and convergence across two diamonds?
Marker: Phase
| Step | Duration | Action | Hint |
|---|---|---|---|
1Phase 1: Discover (Diamond 1, divergence) | 2-6 weeks | Explore the problem space broadly: user interviews, observation, desk research, stakeholder interviews, data analysis. Gather at least 10 data points from different sources. Mark assumptions visibly. | Anyone thinking in solutions during Discover biases research. Strict outcome is a list of insights, themes, and open questions. Do not allow solution discussion. |
2Phase 2: Define (Diamond 1, convergence) | 1-3 weeks | Cluster insights, prioritize, formulate core problem. Write a Problem Statement in one to two sentences. Decider transfers from Discover to Develop with clear problem framing. Explicitly define out-of-scope. | If the problem statement remains vague ('customers are unhappy'), convergence is shallow. For each statement, document source, scope, and impact. |
3Phase 3: Develop (Diamond 2, divergence) | 2-6 weeks | Explore solution space broadly: ideation workshops, sketching, prototyping, service blueprints. Run multiple solution options in parallel and test with users early and cheaply. | Following only one solution in Develop misses the purpose of divergence. At least three options are mandatory, with documented pros and cons. |
4Phase 4: Deliver (Diamond 2, convergence) | Weeks to months | Implement and launch the best solution, then learn. Derive acceptance criteria from Define. Measure outcome against Problem Statement. Iterate from launch feedback. | Deliver without measurement against Define is output, not outcome. If no one checks whether the phase-2 problem was solved, the loop never closes. |
5Phase 5: Transitions between diamonds | Half to one day per transition | Before each diamond transition hold a synthesis workshop with stakeholders. Record written decision point: what is known, uncertain, and next. Decider signs off. | Without documented transitions, diamonds blur into one stream. Synthesis is a required artifact; otherwise no one can later reconstruct what was decided when. |
What comes out at the end
Per phase deliverable: Discover insights report, Problem Statement (Define), solution options with prototypes (Develop), implemented solution with outcome measurement (Deliver). Plus transition documents between diamonds and final outcome report.
Project folder with phase subfolders. Per transition, a versioned synthesis document with date and decider. Later iterations create new double-diamond rounds referencing the prior round.
Compact working template for Double Diamond with context, input, output artifacts, and next step.
Four-phase design process of Discover, Define, Develop, and Deliver with two divergence-convergence diamonds.
When and for what do we use this method?
Which data, observations, decisions, or materials are available?
Short notes along the runsheet.
Owner, date, and success signal.
Concrete filled scenario, fictional example
Concrete filled scenario, fictional example
Discover (3 weeks): 18 user interviews, 6 employee shadowings, analysis of application lead times. Insights: 73% of applications miss required documents, median processing time 47 days, hotline calls before submission are rarely used.
Define (1 week): Problem Statement: 'Applicants do not understand which documents they must submit with the main application, so clarification requests and processing time double.' Out-of-scope: the application form itself (regulatory fixed).
Develop (4 weeks): Three options prototyped: (A) interactive checklist before application, (B) pre-submit completeness check in form, (C) appointment assistant with prelist. Test with 12 users. Option B delivers 89% complete applications versus 41% baseline.
Deliver (8 weeks): Option B implemented, rollout pilot in two districts starting 01.07. Outcome measurement: share of complete applications, median processing time. Review after 90 days.
Transitions: Define transition signed by @sabine (head of administration) on 15.04. Deliver transition signed by @marcus (IT lead) on 12.05.
Recognize symptoms and steer against them
Interviews steer toward 'would an app be helpful?', prematurely locking solution space.
Keep interview guide focused on problems and behavior, not solutions. Anyone proposing 'Feature X would be good' in Discover must return.
Develop starts directly from Discover, problem statement is missing or remains vague.
Treat Define as a required phase with decider signature. Without a problem statement, no Develop. Ask for validation: can we measure solution against the problem?
One solution is followed immediately, no alternatives, no comparison.
Require at least three options with pros and cons. One solution in this phase means you are in the wrong phase.
Solution is rolled out, nobody measures whether the phase-2 problem was solved.
Set outcome measurement in Define and collect it in Deliver. Closing the loop is mandatory; otherwise outcome is unknown.
Phases run in parallel, no one can say where the project stands.
Keep phases visibly separated on wall or board. Set transitions as dated milestones with decider. If iteration is needed, explicitly branch back rather than doing everything in parallel.
Stakeholders learn in Deliver what was decided and then block late.
Include stakeholders in every transition and schedule reviews. Early involvement reduces late veto risk.
Done signals checkable in under a minute
Go to the profile for purpose, similar methods, and sources or continue to the next method in the catalog.