Lean is a way of thinking about creating needed value with fewer resources and less waste.

And Lean is a practice consisting of continuous experimentation to achieve perfect value with zero waste. Lean thinking and practice occur together.​ Lean thinking always starts with the customer. What does the customer value? Or, stated differently and in a way that invites concrete action, what problem does the customer need to solve?  ​Lean practice begins with the 

work — the actions that directly and indirectly create value for the customer — and the people doing that work. Through ongoing experimentation, workers and managers learn by innovating in their work — be it physical or knowledge work — for increasingly better quality and flow, less time and effort, and lower cost. Therefore, an organization characterized by Lean practice is highly adaptive to its ever-changing environment when compared to its peers because of the systematic and continuous learning engendered by Lean thinking and practice. ​A Lean enterprise is organized to keep understanding the customer and their context (i.e., specifying value and looking for better ways to provide it) through product and process development, during fulfillment from order through production to delivery, and through the product’s and/or service’s use cycle from delivery through maintenance and upgrades to recycling.