Background: The Checklist for Early Recognition and Treatment of Acute Illness and Injury (CERTAIN) study is a before-and-after clinical quality improvement study involving 20 countries. Our aim was to describe the challenges and solutions for study implementation across various intensive care units.Methods: After local institutional review board approval, each study center had a setup period before patient data were collected. Each center was required to accomplish 4 stages: baseline data collection, remote simulation training, local implementation, and postimplementation data collection and maintenance of process of care. We measured the time required to complete each study stage and used the Define, Measure, Analyze, Improve, and Control (DMAIC) framework to identify the challenges encountered during each stage and guide improvement strategies to facilitate implementation of CERTAIN.Results: Between June 2012 and December 2017, 55 centers from 20 countries were recruited to participate. The time to complete each stage at different centers varied significantly. The most common domains in which challenges occurred were 1) leadership support and team building, 2) communication, 3) work environment culture, 4) language barriers, 5) infrastructure and technology, and 6) sustainability. Obstacles in these 6 areas delayed reaching major milestones of the study. Different strategies were deployed to overcome these barriers: engaging leadership for support, using native-speaking clinicians during training sessions, using various communication platforms, providing personal computers to local hospitals, making in-person site visits, offering flexible training time, and supporting local centers’ grant applications. Centers that enrolled during the control phase, compared with those that enrolled earlier, had significantly shorter times and less variation in times for each study stage and for the total study time.Conclusions: By using the DMAIC method, we identified the predominant 6 domains in which challenges occurred during implementation of the global CERTAIN study and developed targeted strategies to overcome the challenges and shorten the duration of the study. The DMAIC method would be useful in improving the efficiency of other large-scale multinational quality improvement projects.