Workflow on inactive case

[Jirvine]

I am trying to configure a work flow that will add a task to a case if these conditions are met:

case status <> Closed
There is no activity on the case in 1 week.

I know how to check for the status, but I can't seem to get it to trigger if there are no updates in a week. Is there a way to get it to look for a lack of items being added to the history?

[andopes]

Create a workflow whose value of "Execution Occurs" is "After Time Elapses".
Specify the time elapse and status.

Regards

[Jirvine]

How do I get it to determine that there is no activity though? What field looks at activity on the case? I can't use status because notes can be posted without a status change.

[andopes]

"After Time Elapses" means record not updated for the last x days.
This way you can trigger a workflow as soon as a record remain x days without update AND status is 'Closed', for example.