The Double Diamond design process

A simple, graphical way to describe the design process, ensuring the right questions are asked at the right time.

Developed by the Design Council, the process splits a project into four main phases, showing the different types of thinking which should be used in each. The first two focus on deciding what the project should be about, and the last two on the outcome. Crucially, each of the four steps have equal weight: as much effort should be spent on defining a project as delivering it.

And, although every project is different, the process is flexible enough to be relevant, whether it’s creating a brand-new product or optimising a long-standing business model.


This is where we open up the project by gathering as much information as possible. About the service, the users, the company, the sector - everything.

Activities here could include market research, user interviews, questionnaires and analytics reports.

The goal of this phase is to create the project brief, and signifies the start of the actual, practical design process.


This stage is where we review, filter, refine and often discard ideas from the previous phase. Findings are analysed, reframed as problems and solutions are pitched and prototyped.

Activities could include grouping user journeys into ‘epics’, writing audience personas, building proof-of-concepts and creating low resolution wireframes.

At the end of this phase you’ll likely have a good idea as to how successful the project will be, and is often the place where the decision to stop or continue is made. The Kin probably shouldn’t have got any further than here.


This stage is where things get a bit more open again. We’ve got our clear set of problems, so we can have fun developing concepts and solutions to solve them.

Activities can include brainstorming, designing, prototyping and user testing.


The delivery phase closes things right back down by giving our concept a solid dose of reality, taking it through sign off, final testing, production and launch. Compromises will have to be made.

However, if we’ve followed the process properly we’ll end up with a product which solves the need identified in the define stage, for the reasons set out in the discover phase.

The very last part of this phase is to collect all the lessons learned throughout the course of the project and feed it back into the discovery phase of the next one.

Further reading