Order Placer - A hospital or enterprise-wide system that generates orders for various departments and distributes those orders to the correct department.

Order can be placed from patient floors, outpatient clinics, or by physicians, depending upon the implementation.  The order placer typically does not take into account the specifics about the available resources, such as how many Ct's are available to perform an examination and the times they have an opening.  The Scheduler/Order filler actor manages that for the radiology department.