Lean Startup is a management method for startups to turn an idea into a business; it is developed by Eric Ries.
The term Lean Startup means doing Business in an Agile way. Eric Ries based his method on 5 different principles:
Entrepreneurs are everywhere
You do not need to be in a garage to be a startup. His definition of a startup is: A human institute designed to realise new products and services in extremely uncertain conditions.
Entrepreneurship is management
A startup is a business, not a product. That is why a startup needs een special type of management to cope with extreme circumstances.
Startups do not only exist to ideate, produce and make money from new stuff. Lean startups also learn how you can build a sustainable business. Learning must be validated by regular experiments and research that tests different elements of the vision of the enterpreneur.
The most important activity of a startup is translating ideas in products, measuring how customers react and learn from that by pivoting or pursueing.
In order to judge innovations on its merits, focus on the more boring part of doing business is also needed : how can you measure progress, which milestones do we set, how do we prioritise work, etc…