The Lean Production presents an alternative vision of conventional production, introducing a novel approach that is taking more strength every day worldwide. This new perspective, based on the Toyota Production System (TPS), addresses the causes of many of the problems that limit efficiency, focusing on the reduction of losses along the productive flow, minimizing waste and adding systematically value the manufacturing process
I’ll not bother you about the history of the LEAN philosophy, you can check it in Wikipedia article
The philosophy behind LEAN is the ‘Total Productive Maintenance’ or ‘Total Productive Manufacturing’, and for TOTAL, meaning ‘total participation’ – that’s, everyone in the company – playing an active role in productive flow, adding value to the organization by developing its own staff and associated (suppliers and subcontractors) and continuously solve root problems generating organizational learning. The goal of the system is to eliminate “waste” or “loss” (Muda in Japanese).
I would recomend the following site
to get more information about LEAN and TPM.