Whenever lots of data is managed like SeedDMS does it, there is sooner
or later a need for running certain task, e.g. to do clean ups or
update operations, or simply to check for data changes occurred over
the past. One of the rather obvious operations in SeedDMS is checking
for expired documents. But there are others, like informing users
about reviews or approvals to be due or updating the full text index.
None of them would ever be done without an external trigger, because a
web application is not a constantly running process doing all the
above at recurring intervals. A document in SeedDMS, which has expired
some time ago, will not change its status to expired unless a user
accesses that document and forces SeedDMS to check the expiration date
again. If you were looking at the database, you would see a document
remaining in its old state. In most cases this is just fine, because
nobody actually cares about the status of a document unless it is
being accessed. But there are other cases where it makes a difference.
The full text index, which also stores the status of a document, will
not be aware of the expired documents, unless it is updated regularly.
That’s why the so called scheduler was added in SeedDMS 6.