Some clients have central email or work polling processes that poll for work for multiple business processes. Depending upon the SLA of the work to be done that polling process could either run 24/7 constantly loading work for mulitple processes or scheuduled to run periodically throughout the day in between other main work processes.
I recommend talking to an experienced Blue Prism solution designer or consultant for design discussions like this as there are lots of different options and decisions that need to be made will very much depend upon your own requirements, rather than a generic answer being correct for all clients.