A tool for planning and management of clinical trials. The tool computes a patient enrollment timeline in a clinical trial using multiple factors that bear on the rate of patient enrollment. The factors may be site-dependent factors or may be country-dependent factors. When these factors are applied, different sites may have different rates of enrollment in the same interval. Further, the factors may be time dependent such that even the same sites may have different enrollment rates in different intervals. Once the timeline is created, the tool may use it to calculate a schedule of monitor visits, project trial completion or otherwise generate output used in management of the clinical trial.