Design cycles; There is no 'right' number of iterations in the design process

A frequent question I hear is, "How do you know when you're done?" or "How many rounds of iterations are enough?"

When introducing people to the design process, I often use the double diamond, adding a caveat that it should be seen more as different 'modes of thinking' that designers utilise at different stages, rather than a linear series of steps.

This model can be very appealing to those new to design, as it offers a structured approach. There's a common expectation for clear instructions: just tell me what to do, the steps to follow to reach the final state. The double diamond and other design processes cater to this need.

However, in reality, it's not so straightforward. Design involves constantly shifting between these modes of thinking, and there is no set "right" number of iterations you should aim for.

A frequent question I hear is, "How do you know when you're done?" or "How many rounds of iterations are enough?" My answer, though somewhat frustrating, is: "You know you're done when you arrive at a solution that adequately solves the problem as you've framed it."

What does that mean? It means engaging in iterative design cycles as many times as necessary until you have both adequately framed and solved the problem.

It involves engaging the following design skills or modes of thinking:

1. Problem framing: Initially, designers frame the problem by identifying key aspects and gaps in understanding, not aiming to understand the problem completely (this is impossible) but to generate potential solutions.

2. Prototyping: This helps communicate and validate these solutions. Prototyping serves multiple purposes—it aids in communicating one’s understanding of the problem space and is instrumental in validating potential solutions by testing them and learning which aspects work or do not.

3. Abductive sense-making: This mode of thinking allows designers to generate insights from prototypes and other research, helping refine both the problem and the solution. It involves making intuitive leaps to piece together disparate information, a critical and often innate skill in the design process referred to as 'design intuition.'

The process begins with a challenge, the designer starts by scoping and framing the problem—determining what is most important and what is yet unknown. Exploring solutions occurs simultaneously with problem framing. Sometimes, a solution might reveal a previously unconsidered aspect of the problem, occurring both rapidly through sketches or discussions and more gradually throughout the project.

As the process continues, the designer may conduct additional research to gain deeper insights into the challenge or might develop prototypes from the solutions being considered.

Prototyping is crucial for several reasons. First, it facilitates the early conceptualisation of the challenge and can be revisited throughout the project to refine understanding and solutions. Prototypes are also used for validating solutions and ensuring the problem or challenge is correctly framed. Testing prototypes with users helps identify functional elements of a solution and verifies the framing of the problem.

From there, the designer uses abductive reasoning to synthesise or sense-make what has been learned into new insights or refined solutions. The problem is then reframed with greater fidelity, and the prototypes become more specific, exploring higher fidelity aspects of the solution.

This iterative cycle continues until the team agrees on a defined problem frame and a solution that satisfactorily resolves the identified problem.

The answer to how many iteration cycles are needed to solve a design problem is like to asking, "How long is a piece of string?" The process can be anxiety-inducing and filled with uncertainty, often prompting teams to grasp at the first solution that seems to address the problem. What distinguishes more experienced designers from novices is their confidence in navigating each stage of the process and their ability to judge when the problem has been adequately framed and solved. I call this Design Confidence.

Note: In this context, when referring to 'the designer,' I mean anyone involved in the design process, whether they are professional designers or part of a co-design team.