First up: what is it? Simply put, the Double Diamond model is a systematic approach to conceiving and designing new products and services. The British Design Council conceived and officially launched it in 2005.

The model was not snatched out of thin air, but based on an extensive study the BDC did with global players such as Microsoft, Starbucks, Sony, and LEGO. The idea was to find out how creative people process information and arrive at solutions for complex issues. Based on this research, the BDC developed the model, which is basically a set of systematic actions anyone can follow.

There are four distinct phases in the Double Diamond model: 

1. Discovery

2. Definition

3. Development

4. Delivery

For experience designers, the model is a guide to organise their thoughts and streamline and improve the overall creative thinking process. As every designer has their way of working, the Double Diamond acts as a roadmap that defines the route – it is up to you how you get to the finish, and there is no need to strictly follow the rules.

Before we zoom in on the phases, let’s raise three essential considerations – things you should bear in mind when working with the model.

1. The Double Diamond model is not linear

When viewing the model’s visual representation, you might think it depicts a linear process, but the reality is the opposite. The model encourages designers and design thinkers to move flexibly through the steps to understand better and map the problem and solution. It is an iterative process where, through several rounds, an increasingly better understanding of the problem and solution emerges.

2. The process encourages research and choice-making

Visually, the model consists of diamonds – no flat line. It suggests a process of opening and closing: first, investigating, then making choices. Each diamond represents an act of creating possibilities (diverging) followed by making choices (converging). It’s a way of working that stimulates creativity. 

3. Three key moments

Look at the model – the very shape of the diamonds creates a flow with three key moments in the design process. First, a vague and unclear problem statement, then a clear problem statement, and finally, a clear solution. The model stresses the importance of understanding a problem’s facets before proceeding to a solution. 

After all, the better you understand the problem, the fresher the ideas you come up with, and the better the solution will be.

Now, it is time to get started with the model. 

Phase 1: Discovery, or, learning the context and understanding the problem statement

In this first phase, you try to define and understand all the variables that affect the problem. You consider:

• the preferences and needs of the users for whom the solution is intended

• your business objectives

• the technical or budgetary constraints that determine the solution’s outer limits. 

In addition, you critically examine the problem itself. At this stage, you often discover that it is much more complex than initially thought and that there are multiple ways of approaching it.  The innovative sweet spot lies precisely at the intersection of business objectives, user preferences and technical feasibility.

Typical activities during this phase include discovery workshops, user research, competitive analysis, market research, etc.

The far too empty playground: a multifaceted problem

Suppose you own a playground for children. Think cable cars, trampolines, go-karts, funny wheels, slides, and what have you. But for some reason, only a handful of people flock to your paradise daily, and you desperately want to attract more of them.

During the discovery phase, various reasons arise for why the masses avoid your playground.

• Moms let their children loose at your competitor’s premises because it has an in-house café – sipping coffee with their friends while the kids are running about is so much fun!

• Dads choose another competitor because of the superior climbing equipment for both children and adults, and they love a little joint family activity.

• Children prefer a different playground because an ice cream van regularly stops there.

You can’t solve all these problems at once. There is only one thing to do: make choices.

If by now you thought the Double Diamond model was a magic trick, something to help you effortlessly transition from problem to solution: sorry to shatter that hope. The catch is this: all that digging into the issue can bring up large amounts of information. So, learning how to organise that information is crucial – you don’t just want to look at data and get lost in it, but gain insights you can take further. The trick is precisely to bundle information into useful and valuable insights that determine the next steps in the process.

Phase 2: Definition, or, determining the solution’s fundamental principles

Now that you understand the problem, you have to start making choices and define the principles of the solution. After all, you can never solve everything for everyone – and you don’t need to. During the Definition phase, you pick the problems you want to work on and how you want to do that. 

You can start, for instance, by identifying bottlenecks, looking for hidden risks or opportunities, or writing down a list of things the design team should definitely do (or absolutely not).

This phase’s objective is to work out the different components of the project so that everyone understands the context and can consider the solution's limits. This means, for example, that everyone considers the budget, resources, and market situation before starting work. 

In short, you filter, select, and elaborate on the insights from the Discovery to clarify the definition of the problem. 

Typical activities during this phase include, for example, developing a strategic briefing, making presentations for a management buy-in, defining design principles or design challenges, etc.

Phase 3: Development, or, working out a coherent concept

Now, the real design work starts. In this phase, you effectively start creating the solution to the problem you explored and mapped out in the first two phases.

Oh, and … about the naming of this phase. We know it is confusing to some, as ‘development’ often stands for writing code, but the term is not only used in a techy environment. Yet, Microsoft calls this phase ‘Implement’ while Virgin Atlantic Airways is more likely to say ‘Design’. In this blog post, we’ll just stick to the original and talk about ‘Development’.

The Development phase involves multidisciplinary work. It requires strategists, researchers, UX and UI designers to collaborate with internal and external partners who either bring domain knowledge or inject specific technical expertise into the team.

Bringing everyone together in the same place for a while (this is called design sprints) speeds up the process and avoids pitfalls. For example, imagine a design going into production only to discover a problem with logistics or the production process. Who could have known that? Well, anyone, of course! This is precisely why stakeholders from different disciplines must work together as one team.

Every company deals with this phase differently, but typical activities include brainstorming, storyboarding, moodboarding, visualisation exercises, role plays, etc. They all have one thing in common: they are prototypes to be tested with users, and you can learn a thing or two from them, which may come in handy during the next phase. After all, remember that an idea is only an assumption about reality as long as it has not been tested with real users in a real situation. 

Phase 4: Delivery, or, working out a detailed solution

Finally, you work out all the aspects of the solution – in detail – and subject them to final testing. As a result, you get a detailed concept and implementation plan that an internal or external production team can work with. 

The final test in this step is the last barrier between idea and production. This test removes the last issues from the design and checks the solution one last time for its effectiveness, relevance, and user-friendliness. Although working out the details of the solution may not be the most exciting work, as it is rather executive, testing plays a crucial and strategic role. 

All companies in the British Design Council study said they take this feedback loop very seriously. They see it as the last opportunity to improve the product and remove any thinking error that may have been overlooked before the often expensive production effort.

By the way, this work never stops. Your work as an experience designer is not over after the launch. Some would even argue that only now does the work really start. After all, the product or service has to confront reality – meaning: users in real-life conditions. Once a product or service is on the market, the permanent work of gathering feedback and translating it into the next version of the design starts. So, forget the launch sprint and prepare for a continuous improvement marathon!