You can set a locking strategy for a case type to control how cases are accessed in your application. By using locking strategies, you reduce the risk of lost updates to a case by concurrently working users.
Open a top-level case type in Case Designer.
On the Settings tab, click Locking.
Click a locking strategy.
A case is opened — Allows one user at a time to open and work on a case.
This default strategy locks the case for 30 minutes or until the user submits or closes the case, whichever comes first.
An action taken on case — Allows multiple users to work on a case at the same time.
This optimistic strategy allows the first user to submit the case to succeed. All other users who are working on the case are notified and must review the changes before they can submit their own updates.
Optional: Enter a number of minutes in the Release lock after field to override the default value.
Click Save.
The locking strategy is applied to new and existing cases. It is also inherited by all descendants of your case type, but some aspects can be overridden.