Lean involves a fundamental paradigm shift from conventional "batch and queue" mass production to product-aligned "one-piece flow" pull production. Whereas "batch and queue" involves mass production of large lots of products in advance based on potential or predicted customer demands, a "one-piece flow" system rearranges production activities in a way that processing steps of different types are conducted immediately adjacent to each other in a continuous flow.

This shift requires highly controlled processes operated in a well maintained, ordered, and clean environment that incorporates principles of employee-involved, system-wide, continual improvement.

While most of these methods are interrelated and can occur concurrently, most organizations begin by implementing lean techniques in a particular production area or at a "pilot" facility, and then expand use of the methods over time. Companies typically tailor these methods to address their own unique needs and circumstances. In doing so, they may develop their own terminology around the various methods.

Explore different methods in the box at the right. A summary of the environmental implications of each method is also available.