As a Head of Product Design, I’ve worked across startups, enterprise systems, public services and everything in between. And if there’s one thing I’ve learned, it’s that there is no one-size-fits-all design process. Yet designers are often expected to apply a cookie-cutter method to every challenge. That’s a recipe for mediocrity.

Instead, we need to be adaptable - choosing the right process for the right problem.

In this article, I’ll walk through the most widely used design processes—Double Diamond, DMAIC, Design Thinking, Lean UX, Agile UX, Service Design, and more. I’ll explain what each is, when to use it, and what kind of problems it solves best.

Why Design Process Even Matters

Design processes aren’t just for staying organised — they’re tools for thinking. They give teams clarity, shape collaboration, and make decision-making visible.

A good design process:

a) Aligns teams on what problem to solve.

b) Structures how to explore ideas and test solutions.

c) Balances creativity with constraints.

d) Helps scale design beyond individual effort.

Choosing the wrong one? That can waste time, money, and (worst of all) user trust.

Let’s dive in.

1. Double Diamond — Best for framing messy problems.

What it is: Developed by the UK’s Design Council, the Double Diamond is a simple but powerful visualisation of the design process split into two phases: Discover–Define and Develop–Deliver.

Use it when: You’re tackling a vague, complex problem or starting from scratch. Great for uncovering user needs and aligning cross-functional teams.

Example: At one organisation, we used the Double Diamond to reimagine how users accessed critical services across multiple government departments. The early divergence helped us expose pain points no one had spotted before.

Benefits: Encourages divergent and convergent thinking. Helps teams avoid solution bias. Simple to explain to stakeholders.

What it is: DMAIC stands for Define, Measure, Analyze, Improve, Control. Originating from Six Sigma, it’s a rigorous, data-driven approach to optimising existing processes.

Use it when: You’re improving a known experience—like reducing errors in a checkout flow or speeding up a form completion process.

Example: I used DMAIC to reduce drop-off rates in a product onboarding flow. By measuring and analysing real behaviour, we uncovered unexpected friction and reduced abandonment by 18%.

Benefits: Empirical, outcome-focused, great for incremental gains and repeatable wins. It brings a level of accountability to UX that’s often missing.

3. Design Thinking — Best for innovative, user-centred problem solving.

What it is: Popularised by IDEO and Stanford d.school, this five-step model (Empathise, Define, Ideate, Prototype, Test) puts users at the centre of design decisions.

Use it when: You need to create something new or radically rethink a product or service. Especially useful for workshop formats.

Example: While redesigning a legacy B2B dashboard, we used Design Thinking to co-create with users, leading to insights that internal data alone never surfaced.

Benefits: Easy to learn, widely accepted. Encourages cross-discipline collaboration. Works well with non-designers too.

4. Lean UX — Best for fast, iterative environments.

What it is: Born out of the Lean Startup movement, Lean UX is about building quickly, measuring constantly, and learning fast.

Use it when: You’re working in Agile or startup environments, where speed and iteration trump perfection.

Example: During a pilot project for a mobile app, we ran Lean UX cycles weekly, testing low-fidelity prototypes with users on Friday and iterating over the weekend.

Benefits: Lightweight, fast feedback, reduces waste. Perfect for MVPs and experimental work.

5. Agile UX — Best for embedding design in development sprints.

What it is: Agile UX integrates design activities directly into Agile sprints.

Use it when: Your team is sprint-based and delivery-focused. Agile UX helps you work alongside devs without sacrificing user insight.

Example: We embedded UX designers into Scrum teams, ensuring research and iteration happened concurrently with development—without bottlenecks.

Benefits: Keeps design relevant and timely. Supports real-time iteration. Ensures UX isn’t an afterthought.

6. Service Design — Best for designing complex, end-to-end services.

What it is: Service Design takes a holistic view of experiences across channels, touchpoints, and back-end operations. It maps services end-to-end.

Use it when: You’re designing across departments or need to account for both user and business needs.

Example: At a large health provider, we used Service Design tools like service blueprints and stakeholder maps to redesign the patient journey across physical and digital touchpoints.

Benefits: Holistic, inclusive, aligned with organisational change. Goes beyond screens into systems.

7. Jobs To Be Done (JTBD) — Best for understanding user motivation.

What it is: JTBD reframes product thinking around the job the user is trying to get done, rather than personas or demographics.

Use it when: You’re developing features, messaging or UX copy. JTBD sharpens your understanding of motivation and desired outcomes.

Example: We used JTBD to improve feature onboarding, focusing less on technical explanation and more on helping users accomplish their underlying task.

Benefits: Clarity around user goals. Aligns UX and product teams on user outcomes.

How I Choose the Right Process.

I never default to a single method. Instead, I ask:

- Is this a new or existing experience?

- Do we need speed, innovation, or control?

- Are we solving a known or ambiguous problem?

- What’s the risk of getting this wrong?

Sometimes, the best approach is hybrid. For example:

- Use Design Thinking to explore, then DMAIC to improve.

- Start with Double Diamond, then switch to Agile UX during delivery.

So... which one should you choose?

Final Thoughts

Processes are tools, not rules. The best designers know when to flex and when to follow. It’s less about the process you use, and more about whether it suits the challenge you’re solving.

Understanding these frameworks gives you language, structure, and confidence—but it’s your judgement that makes the difference.

Design is not about process. Design is about outcomes.

And the right process helps you get there faster, smarter, and more creatively.