This chapter surveys the major quality improvement (QI) models used in hospitals and shows how to apply them at the bedside and across services. We explain the Model for Improvement/PDSA, Lean, Six Sigma/DMAIC, Kanban, and 5S methodology, detailing aims, core steps, and when each fits best along with examples of healthcare setting. It also covers common challenges. Also, clarifies often-confused methods: a gemba walk is “go see” work to understand context and barriers; a waste walk is a focused pass to spot the seven wastes (plus underused talent). We outline the cycle of change from readiness, small tests, adoption, spread, and sustainment with measurement and feedback at each stage. The chapter includes practical error-proofing (poka-yoke) tactics for high-risk steps, forcing functions for look-alike/sound alike drugs, barcode medication administration, hard stops for contraindications, standardized kits and checklists, and visual controls to convert human fallibility into system reliability. The goal is simple: choose the right model, run disciplined tests, and lock in safer, faster, and more reliable care.