The 21st century is an age of digitization of health information. Hospitals and health systems around the world are implementing Health Information Systems (HIS). These systems provide a comprehensive electronic data capture of patient personal information, diagnostic results, clinical treatments and outcomes gathered as part of treatment and care. Digitizing health information is meant to improve patient safety, reduce errors, speed information transfer and hopefully lead to better patient outcomes and more effective and efficient care processes. Past evaluations have found some of these outcomes, but there have been no robust Canadian evaluations, and none seem to have considered patient and provider experience as a core measure of implementation success. Trillium Health Partners (THP) is one of Canada’s largest community hospitals and they are currently implementing a new health information system to replace some 22 other legacy systems. Led by Dr. Walter Wodchis (Research Chair of Implementation and Evaluation Science and IBH Scientist) and a diverse team of scientists and clinicians, this project aims to use this large-scale transformation to rigorously study the impact of implementing an HIS on patient experience, health outcomes, provider experience and total cost of care at THP. The project team will study this with the purpose of both improving the local implementation success and creating new knowledge for others about the causes for successes and failures so that future implementations will have a higher likelihood of early success.