Yes this is certainly one alternative to use Case Aggregate Feature to sum the values from Child Cases. But how do one actually prevent Child case from Accessing Parent Case details ? This is because when Child case is opened then pyWorkCover (Parent) is opened by default. The child can use breadcrumb or links (in pyCaseManagerPortal) to open the parent and thereby access the parent case detail. How is it possible to prevent by defining an Access When Rule ?