Synchronized groups
A synchronized group is a group of actions whose processing is controlled so that only one action is processed at a time. The group is defined within one or more business classes, and can include more than one action. They are defined by the application developer.
Synchronized groups are created by the system when needed. You can view any existing synchronized groups on the Synchronized Group Management tab of the Async page. If many empty synchronized groups exist, you can remove the empty groups. An empty group is one with no active members, that is, no pending scheduling requests in the group and no requests in the group with unfinished triggers.