The WAS help says
"This setting configures whether the application's process pool should be automatically flushed and, if so, how often. You can specify that Web Application processes are closed and reopened after a specified number of hours."
But how gracefully does it do it? For example, if the process is in the middle of a long running webservice call with lots of data open and some saves not yet completed, will it just shut everything down and risk corrupting the data?