Lean Startup ToolsTest the idea before you build it

The Lean Startup by Eric Ries: a short summary

The Lean Startup, published by Eric Ries in 2011, applies lean thinking to new products under uncertainty. Ries drew on lean manufacturing and on Steve Blank's customer development.

Its central claim is that a startup's job is to learn what customers want, quickly and cheaply. Ries calls this validated learning and treats it as the unit of progress, rather than features shipped or plans met.

The book's main ideas are the build-measure-learn loop, the minimum viable product, innovation accounting with actionable metrics, and the regular decision to pivot or persevere. It also borrows small batches and the five whys from the Toyota Production System. The lean startup methodology guide covers each idea in more depth.

How build-measure-learn works

Build-measure-learn is the feedback loop at the center of the lean startup. Each turn of the loop tests one assumption, and the aim is to get through it as fast as possible.

Start from the riskiest assumption. Ries calls these leap-of-faith assumptions, chiefly the value hypothesis (will people use it?) and the growth hypothesis (how will it spread?).

Plan the loop backwards: decide what you need to learn, then what to measure, then the smallest thing to build. Build that MVP, measure real behavior with A/B testing tools, and learn whether to pivot or persevere.

The loop is a form of PDCA: state a hypothesis, run a test, check the result and act on it.

Run the cheapest test first

Tests range from cheap to expensive. Start with customer interviews, then a landing page or smoke test. Next come a concierge service run by hand, and a "Wizard of Oz" product with manual work behind it. A working MVP comes last.

Start at the cheapest test that can answer the question. Many teams build an MVP when a few interviews would show the problem is not painful enough.

Customer discovery tools support interviews. MVP tools cover smoke tests and working prototypes.

Actionable vs vanity metrics

Ries contrasts actionable metrics, which show cause and effect, with vanity metrics such as total sign-ups. A vanity metric can rise while the business gets no closer to working.

Cohorts and controlled experiments make metrics actionable. A/B testing tools compare versions on real behavior, so you can decide to persevere or pivot.

Lean canvas vs business model canvas

Ash Maurya created the Lean Canvas in 2010 as a one-page business model for startups. It adapts Alexander Osterwalder's Business Model Canvas.

The business model canvas maps an existing business as a whole. The lean canvas swaps in boxes for the problem, the solution, key metrics and an unfair advantage.

That makes it a better fit for an idea that is still unproven. Lean canvas tools keep versions, so you can see how the model changed as evidence came in.

The lean startup toolkit guide pairs a tool with each step of the loop.