The Two Sides of Lean Startup
Eric Ries observed that Customer Development and Agile Development are natural complements addressing two different unknowns:
Ries combined them at IMVU (co-founded 2004), where he applied Blank's Customer Development methodology alongside agile engineering practices. He began formally documenting the synthesis on his blog in 2008, and published "The Lean Startup" in 2011.
Agile Alliance Recognition
The Agile Alliance formally recognizes Customer Development in its glossary, describing it as "a framework first presented by Steve Blank in his 2005 book The Four Steps to the Epiphany." The glossary notes that Customer Discovery "is the part of the framework that plays the biggest part in Lean Startup and has also been shortened to 'discovery' by some in the agile community."
Lean LaunchPad Integration
In the Lean LaunchPad class (Stanford, January 2011), Blank structured the course around three pillars: the Business Model Canvas, Customer Development, and Agile Engineering. The weekly cadence functions like an agile sprint:
Significance
The Agile-Customer Development synthesis is the methodological core of the Lean Startup. Without Agile, Customer Development would produce validated hypotheses but no mechanism for rapid product iteration. Without Customer Development, Agile would produce well-built products that might not solve real problems. The combination makes both sides accountable to evidence.
Sources: Agile Alliance glossary, Wikipedia (Lean Launchpad, Eric Ries), steveblank.com