The customer development process in Lean B2B alternates between divergent and convergent phases to explore, refine, and validate the elements of your business plan.
The UK Design Council created the Double Diamond design process in 2005 to capture this innovation process. It has since been widely-adopted in user experience design and is the foundation of the interview and customer development process I follow.

The 4 Phases of the Customer Development Process
The first part of the Double Diamond process helps entrepreneurs define the problem (customer discovery) while the second part is used to validate the solution (customer validation).
Although going through the four phases of the Double Diamond process might not require four separate customer interviews, all of these phases will need to be part of the customer development process of your startup if you are to be successful:
- Discovery – Problem interview (divergent)
The starting point of the problem interview phase can be as little as a market insight around which you try to explore and discover problems and opportunities. Whether you have a good hunch for a problem or not, it’s best to start with a divergent interview to explore as widely as possible and learn about your prospects, their company, and their problems. - Drilldown – Problem interview (convergent)
The second problem interview helps the entrepreneur home in on problems and dig deep to understand the root causes and the impact that solving this problem would have. - Exploration – Solution interview (divergent)
The solution interview phase begins after you create a solution to your prospect’s problem. This stage is about exploring, iterating and testing the minimum viable product to maximize its impact and relevance with prospects. - Confirmation – Solution interview (convergent)
The final phase of the solution interview is about confirming that the solution provides enough value for money to change hands. The outcome of the confirmation stage is a solution that has been validated or invalidated by prospects, and a business model.
Plan to go through these phases in two, three, four, or more interviews. Although more than two interviews might feel like overkill for you, it’s best to plan for more than less and take your time.
Don’t rush customer discovery. Don’t settle for solving a low-impact problem for companies.
More on the B2B Customer Development Process
- How to Find Your Best Customers with a Market Segmentation Analysis
- How to Setup a Customer Development Panel in B2B
- 17 Fundamental SaaS Frameworks B2B Entrepreneurs Should Use
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