Design Thinking Series - Part 2: Process - Double Diamond

René Andersen May 12, 2021

The design thinking series examines the complexities and concepts that comprise design thinking. In defining our approach to this way of problem solving and developing human-centred solutions, we hope to provide a clear understanding and ideas for practical applications. The following blog was created by our resident design thinking coach René Andersen. 

The previous post began to scratch the surface of design thinking. It touched on a number of its aspects, including process, team, coach, and mindset. In this post, I like to tackle process, and explore:

  • What do you actually do when you do design thinking?


Let’s begin with pictures you may find when you go looking for “the design thinking process”.


These are examples of ways in which design thinking processes have been visualised. This selection is not conclusive, and organisations tend to keep creating their own versions as we speak (SAP and IBM are shown above as two such examples).

When I worked as part of an internal innovation team at Transport for New South Wales (Ministry of Transport) in Sydney back in 2016, we did the same thing - we took some basic building blocks of the design thinking process and wove them together with some of the processes and concepts that were used at the Ministry at the time.

This can be a useful exercise as it forces you to think about how components of design thinking harmonise (or fail to harmonise) with the unique, pre-existing reality of your organisation. If successful, this exploration will result in an integrated and enriched view of the way things are done in your organisation. It will also highlight opportunities for improvement or refinement because design thinking tends to put things on the map that many organisations aspire to (e.g. working in ways that are genuinely collaborative, innovative, efficient, and fun).

Let‘s have another look at the picture of the different process models. While their differences may be confusing at first, a closer look reveals that:

  • some models are more widely known and used than others, and
  • underneath the differences are significant similarities.

In view of the first point, it’s probably fair to say that the three models in the top row are among the most widely used today and tend to be the ones shown in formal design thinking trainings. If you understand these three models you will have a good compass for navigating the rest of the design thinking process jungle.

D.School, HPI and the Double Diamond

I was trained in the so-called HPI model. HPI stands for “Hasso Plattner Institute”. Hasso Plattner is one of the founders of SAP. He’s also a billionaire and philanthropist. In that capacity he founded the design thinking institute known as the “” at Stanford University in the U.S., and he also founded the sister institute known as the “HPI”, which is located near Berlin in Germany.

The HPI in Germany and the in the U.S. are design thinking centres of excellence to this day. The corresponding process models are very similar. The HPI model has 6 phases, the model has 5, but the last three phases are identical.

Also famous is the so-called Double Diamond model by the British Design Council, pictured as the third model in the top row.

The Double Diamond is often combined with the HPI and models. The first diagram in the second row shows one such common juxtaposition. It is this diagram that I personally find the most useful of aIl models, and it is this one that I like to use for our initial examination of the design thinking process.

A good understanding of this diagram provides you with a key to unlock and understand any design thinking process diagram that anybody may put in front of you, including the so-called “Design Sprint” (which has become popular in recent years), the IDEO diagram, and the “Fuzzy Process” diagram (all included in the picture above).

The HPI & Double Diamond Process Model

Let’s take another, closer look at this picture then, which combines the Double Diamond and the six HPI phases. The Double Diamond represents a coarser level of granularity. We will start with that and become more fine grained in our examination once we‘ve understood the process from the high level Double Diamond perspective.


Double Diamond

The Double Diamond are the two grey shapes in the background. They are labeled “Problem space” and “Solution space”.

Design thinking is very disciplined about distinguishing problem from solution. It advises not to think about solutions until you’ve gained a good-enough understanding of the problems. This advice is based on the experience that if you lift your empathic gaze off the people in front of you (with their often complex and conflicting needs) and start to think about solutions too early, then you can end up solving the wrong problem. The first diamond is all about research. You study the people, you study their needs, their behaviours, their work-arounds, their unsolved problems.

It often comes as a surprise to people new to design thinking that about half of the available time in an initial design thinking workshop is spent exploring and understanding the problem space. Only after spending sufficient time with the people whose problems you are trying to solve do you move on to start exploring potential solutions. The fact that the two diamonds are equal in size is a visual representation of this recommendation.

If the first diamond is about solving the right problem, the second diamond is about building the right solution. The process of the second diamond comprises ideation, prototyping and testing. Here, you try to quickly and cheaply build something that looks like it might solve the problems. Then you test it to find out whether it does or does not. You note what people like about your proposed solution, what they don’t like, what they don’t understand about it, and any ideas they might have about how to improve it.

This is where you get to at the end of the second diamond: an initial, validated prototype. Something that tangibly represents an idea for a solution, and because of its tangibility allows you to effectively test it with real people and get some real feedback.


While the number of diamonds (two) is significant, their shape is also. The diamond shape is intended to visualise two very different modes of thinking and working: divergent and convergent.

You always begin a design thinking process in a divergent mode of working: you open up wide to take in a broad spectrum of information, you think in loose associations and generate lots of points of reference. A design thinking team in this initial phase of the process could, for example, create a mind map of all the stakeholders, users, and user problems it can think of, and of any topics that the team thinks might be relevant to the project. In a next step, the team might go out and interview a number of potential users and stakeholders and thereby generate further material. This would still be part of the divergent mode of working, which generates an increasing amount of raw material.


At some point, however, the team will switch to a convergent mode of working. After having completed an initial set of user interviews, the team will typically shut the flood gates to any additional information and switch to analysing all of the information gathered so far. This might involve clustering information by topics, finding patterns, identifying duplicates, condensing insights and generally converging to a more narrowly defined articulation of a problem worth solving.

You see, typically the task that a design thinking team starts with at the beginning of a design thinking process is quite broad. In design thinking jargon, it is called a design thinking challenge and is deliberately formulated in a rather open way that invites further exploration of who the people (users) are, and what their needs and pain points consist of.

The end of the first diamond marks the end of the exploration of the problem space. At this point in the process the design thinking team should have gained a good understanding of who the users are and what their key unmet needs and pain points look like.

Often, there are many different users with many different needs and pain points. There are lots of problems to be solved. Because design thinking workshops are typically time boxed, and a design thinking team can only achieve so much in a given time frame, this is the point in the process where the design thinking team decides which subset, or part of the problem, it wants to solve in the current workshop (keeping in mind that it may have a chance to tackle other subsets in subsequent workshops as it starts to iterate - we’ll cover this later).

For example, if the initial design thinking challenge was “Improve our workplace” (very broad), then at the end of the first diamond, the team might have converged to a problem definition like “Improve the efficiency of our onboarding process” (much narrower).

Divergence - Convergence. Repeat.

The team now enters the second diamond and goes through the alternating divergent - convergent rhythm once more. Just like it did at the beginning of the first diamond, it begins the second diamond by working in a divergent manner: it stretches its imagination wide and generates lots of ideas, including far-out, crazy ones. At some point, it stops generating ideas and switches to a convergent mode of working. It analyses the ideas and selects one or two, which it assesses as being the most promising ones to solve the problem it had articulated at the end of the first diamond.

Next, the team prototypes the selected ideas. This means it will quickly and cheaply create something that it can test with users. In a software project, this may be a paper prototype, or a few sketches.

The final part of the second diamond consists of the testing of the prototype. This results in the second and final point of convergence: tthe feedback that users give about the prototype. With that, the Double Diamond has been completed.

In summary, the process symbolism of the Double Diamond is twofold. It counsels to:

  • distinguish problem from solution, and spend sufficient time exploring the former before starting to think about the latter;
  • systematically oscillate between divergent and convergent modes of thinking as a way to efficiently and effectively work your way through a design thinking cycle.

From the Double Diamond on to the Six HPI Phases

Now that we have covered the topic of process from the high level perspective of the Double Diamond model, we are ready to deep dive into the more fine grained HPI model that splits a design thinking cycle into six distinct phases. This is what I would like to explore in a subsequent blog post. As we will see, the six phases map neatly and symmetrically on to the Double Diamond: the first three phases are located in the first diamond, the latter three phases in the second diamond.

Exploring these six phases will provide us with a more fine grained understanding of the design thinking process and give us the opportunity to delve more deeply into some of its more well-known components, such as empathic user interviews, how-might-we questions, creative ideation, pragmatic prototyping and straight-faced testing.


D.School (Hasso Plattner Institute of Design at Stanford University): Stanford
HPI School of Design Thinking (at the Hasso Plattner Institute in Germany): Hasso Plattner Institute
British Design Council: Design Council

René Andersen, Senior Product Owner and Design Thinking Coach at Trineo

Currently based in Christchurch, New Zealand, René has worked in digital transformation and innovation for more than thirteen years - across Germany, New Zealand and Australia. From large organisations to Start Ups, René enjoys combining methodological rigour with creativity and empathy, and is passionate about human-centered & iterative approaches to innovation and transformation. 

René Andersen

René Andersen