In today’s rapidly evolving technological landscape, companies and organizations need to adopt an integrated approach to ensure cost-effective and optimal asset operation and utilization while minimizing downtime and risk. Asset operations and maintenance (O&M) play a pivotal role in infrastructure and industrial systems’ overall performance and longevity. This chapter provides a concise overview of the key considerations and functions in asset O&M. It first reviews the importance of asset O&M in enhancing the operational efficiency of assets. Second, this chapter discusses five primary functions of O&M, including (1) maintenance and repair; (2) security management; (3) documentation management and control; (4) work order management; and (5) emergency response and management, and their corresponding definitions, key function or elements, potential digitalization benefits, and current challenges. This chapter aims to provide a comprehensive overview of the latest developments in asset O&M for university students, scholars, and professionals, enabling them to equip themselves with solid asset O&M knowledge and real-world practice.