Define Lean

Lean is a manufacturing process that was developed by Toyota in 1988.
It is based upon 2 key principles – the removal of irregularity and the removal of irrelevance. That is, attempting to get uniformity within production and removing wasteful processes.  It uses a whole set of tools:

Kanban – enabling just-in-time delivery within production, so that stock is not held waiting to be used.

TIMWOOD – an acronym for Transport, Inventory, Motion, Waiting, Overproduction, Over processing, and Defects; all areas for examination of savings that are probably the most commonly referenced.

The main idea of the Lean process is to get the most streamlined process within a production environment.  It wants to create the most consistently “good product” in the most efficient way.  The value of Lean begins with identifying activities to add value to processes or services and making sure that value-added activities are performed effectively and efficiently.

By beginning with waste removal, Lean processes are able to build in synchronized activities which minimize unnecessary or excessive activities.
Once processes have had waste removed, Black Belts typically review performance and design to reduce error rates and variability, thereby reducing waste and non value-added activities. These are the two main goals of Lean.