Toyota has been the world's largest automaker since April 2007 due to its focus on quality, reliability, and customer loyalty. Toyota's production system known as TPS emphasizes eliminating waste through just-in-time manufacturing and continuous improvement. The key concepts of TPS include Jidoka (stopping production to prevent defects), Kaizen (continuous improvement), and Andons (visual controls providing real-time production updates). While competitors have studied TPS, Toyota's real secret is its focus on helping suppliers and using lean product development principles, not just TPS alone.