There are several different ways to shut down IMS, depending on the type of control region that is running (DB/BC, DBCTL, or DCCTL), and whether or not the IMS message queues are required following the next IMS startup.

A common sequence for shutting down the entire online IMS system is:

1. For an IMS DB/DC or DCCTL environment, stop the transactions.

   For an IMS DBCTL environment, disconnect from the coordinator controller (CCTL).

2. Stop the dependent regions.
3. Stop the control region.
4. For an IMS DB/DC or DBCTL environment, you might want to stop the IRLM, but you do not have to stop IRLM in order to stop IMS. Be careful in stopping an IRLM because other IMSs might be using it.
5. For a shared-queues environment, you might want to shut down the Common Queue Server (CQS), but you do not have to stop CQS in order to stop IMS. Be careful in stopping a CQS because other clients might be using it.
6. For an IMSplex environment, shut down the IMS components that participate in the IMSplex, and then shut down the Common Service Layer.

Related Reading: For more information about:

• Shutting down an IMS, see the Shutting Down IMS.
• The commands involved in shutting down an IMS, see the IMS Commands.