This book provides a comprehensive introduction to operational excellence (OPEX) and its potential benefits in the public sector, offering a practical roadmap for preparation, implementation, and long-term sustainability. Through real-world case studies from diverse public sector organisations — including healthcare, law enforcement, higher education, and local government — it illustrates how various OPEX methodologies can drive efficiency and effectiveness.While many public sector organisations have embraced methodologies like Kaizen and Lean, sustaining OPEX initiatives remains a challenge. Few have fully integrated Lean Six Sigma due to cultural resistance, a lack of formal infrastructure, limited skills and competencies, insufficient visionary and strategic leadership, low awareness of the integrated approach, and limited strategic alignment. Senior management often fails to prioritise OPEX, leaving critical improvement opportunities untapped. This book addresses these challenges, equipping leaders with the knowledge and tools to successfully implement and sustain OPEX in the public sector.