The utility of the IVRS/IWRS is not just limited to the randomization. It can be used in other areas as well:
Collecting the clinical efficacy outcome. For example, in IBS (Irritable Bowel Syndrome) study, the IVRS is used to collect the information about the presence or intensity of several IBS related symptoms daily (such as satisfactory relief, Abdominal discomfort or pain, Bloating, Stool frequency, Stool consistency...)
Patient Reported Outcome (ePRO)
Outcome research
Cohort management (open/close a cohort) in dose-escalation studies
Patient registry / registry studies
Drug supply managment / Study drug inventory tracking