When you iterate, you repeat what you have already done in order to improve, which means that the stages in the design thinking process are not simply sequential.
For some, iteration is a strange activity because they imagine that things they have already done are fixed and finished. In design using an iterative mindset means that you assume that the information you have gathered, ideas and prototypes you have developed are NOT yet finished despite your efforts to develop them; instead, they are just a first attempt that will require far more elaboration. Iteration obliges you to get involved in a continuous loop of learning, which puts it at the heart of a design thinking process.
The design thinking process is suited to deal with problems that are ‘wicked’, meaning that there is not one simple solution. In many cases there even isn’t a steady problem definition because many interdependent factors can cause the problem. For example, what is exactly the cause of poverty, or of climate change? To fight climate change, for example, should we focus on CO2 emissions, reconsider our traveling habits, cut back nitrogen emissions in agriculture, reflect on our consumption patterns, make our cities bike-friendly? In such wicked problems, the interconnection of all these factors means that the phenomenon is not only impossible to grasp in its entirety but also changes over time. We need a problem-solving process that can deal with multifaceted conditions, that invests sufficient time in developing a relevant point-of-view for the issue, and that provides opportunities to adapt and learn during the process.
To find a valuable solution to a wicked problem, you must gain a deep insight into the many elements involved, and learn how to (re)frame the problem, which will necessarily result in a new and creative approach. Because you never know whether your solution is final, you cannot simply test your solution to determine whether it is ‘right’. The designers can neither hide behind assertions that they are ‘right’ nor excuse their actions and solutions by saying that they found out that they were ‘wrong’. The solution that design thinkers develop goes beyond these (analytic) categories of right and wrong, which requires that they take full responsibility for their actions. They have to be able to continuously learn and adapt to come up with something that is valuable.
Continuous loops of testing, getting feedback and improving the prototype are of course also part of other strategies such as Agile and Lean, particularly in software development. Although these iterative approaches work well for product development, they imply a strong conviction of what the ‘right’ idea is. The subsequent processes of rapid prototyping and testing then aim to meet the stakeholders’ changing requirements. Where iteration in Agile and Lean is part of developing the ‘solution space’, in design thinking, iteration is also part of discovering the ‘problem space’ involving the idea or frame that is used. For example, a team may find that its unique design vision is not working and that its point-of-view must be adapted or more information from field research is required, or that other elements of the system must be taken into consideration. In design thinking, iteration dominates the whole process, thus putting the design team in a continuous mode of learning to be able to deal with wicked problems.
Of course, you cannot continuously repeat the steps that have been taken. Iteration has a pragmatic side to it which means that teams should try to get feedback/feedforward and learn within the time and resources available. The first lesson on how to implement iteration in design therefore is that it is primarily a mindset for continuous learning, where iteration guides the whole process. The second lesson is that, during a design thinking process, it is good to explicitly devote some (session) time to a ‘repetition’ of steps that might be considered done.
Practically this means that it is suggested to develop not one, but two or three rapid prototypes: this transmits the message that there is not just ‘one right solution’ and that learning must continue.
Then, if in a next step one prototype is chosen, try to get feedback from a wide range of stakeholders.
Make getting feedback a structured process (see Testing Grid).
Devote another session to a further (iterative) development of that one prototype in which the feedback is integrated.
Conditioning factors like the time and resources available will determine how many of these learning loops can be actively executed in these sessions. The main message is to stimulate these learning loops in the minds of the team members. Create a work environment that is playful, allows for curiosity and input from unexpected perspectives (invite an artist and the like), relieves the stress and notions of ‘reaching targets’, etc.