This book explains why the traditional materials planning environment, typically embodied by an Enterprise Resource Planning (ERP) system, is an ineffective support system for a company that wants to adopt Lean practices. It offers an alternative methodology for implementing Lean into the supply chain that allows for ongoing experimentation, learning, and improvement. After defining supply chain management and Lean basics, it explores the conflicts between Lean and the traditional framework. It includes a chart that matches Lean tools with the planning and control charts that have served as the model for ERP systems.