Lean management originated in mid-twentieth-century manufacturing as a philosophy centered on maximizing customer value by systematically eliminating waste. Rooted in the Toyota Production System, its guiding tenets—continuous improvement, respect for people, and a pull-based approach driven by actual demand—have been embraced far beyond auto assembly lines. Over time, lean thinking migrated into services, healthcare, construction, logistics, and even government, demonstrating its versatility in any environment where processes and information flow can be optimized. Central to lean is the relentless quest to identify activities that do not add value—ranging from overproduction to unnecessary motion—and to remove them through small, incremental changes. Tools such as kaizen promote daily problem solving at all levels, while value stream mapping reveals inefficiencies across entire workflows. Techniques like 5S organize workspaces for clarity and safety, and pull systems align work with real-time customer needs. As lean spread into healthcare, it enabled hospitals to reduce patient wait times and streamline care pathways. In construction, it improved project scheduling and collaboration. Across industries, lean fosters a culture of empowerment, where frontline employees contribute ideas for ongoing improvement. By focusing on value from the customer’s perspective and equipping teams with practical methods to eliminate waste, lean management transforms organizations into agile, efficient, and continuously learning enterprises.