Always confused with time-outs in a web-forms environment, so I wrote it in very short terms down to be memorized. Note 549735.1
on Metalink is the best source by the way where it is explained what time-outs you can use best, in this kind of environments

Three parameters of vital importance:

* FORMS_TIMEOUT to be configured in .env-file = per application, defaults to 15 minutes.
* Heartbeat to be configured in formsweb.cfg (default), or in .env-file, defaults to 2 minutes.
* Session-timeout to be configured in web.xml, for example:

- No timeout occurs when:
* heartbeat < forms-timeout.
- Time-out occurs when:
* heartbeat > forms-timeout      or
* heartbeat > session-time out

For example : two applications running on the same BI_FORMS- java container, one needs to be timed-out after 10 minutes, the other the customer don’t want to be timed-out:

———————-Application timing out           Application not te be timed out
FORMS_TIMEOUT            10                                                                         15
heartbeat                              12                                                                         12
session-timeout                 13                                                                         13

So in this case I used the formsweb.cfg (heartbeat) and the web.xml (session-timeout) to be the ‘fixed’ timeouts. And per application (.env-file) I can decide if they are timed-out or not.