Continuous Commissioning (CCSM) is an ongoing process to resolve operating problems, improve comfort, optimize energy use, and identify retrofits for existing commercial and institutional buildings and central plant facilities. CC focuses on optimizing/improving overall system control and operations for the building as it is currently utilized and on meeting existing facility needs. Innovative optimal engineering solutions are developed using engineering-based model analysis integrated with scientific field measurement. Integrated approaches are used to implement these solutions to ensure practical local and global system optimization and to ensure persistence of the improved operational schedules. Implementation of the CC process has typically decreased building energy consumption by 20% in well over 100 large buildings where it has been implemented. This paper presents the CC process, the primary CC techniques and measures, and a case study.