A process in CICS triggers JOBA which in turn triggers JOBB. There can be many JOBAs in the queue, but each should wait for a run of JOBB in between.
Using VRM for this sequencing of the work is best. You can set up JOBA to have a COREQ VRM resource with JOBA requiring the resource to be inactive and JOBB to have the resource active. You would need to change JOBA to have a first step that executes the trailer step in 7 to do a PRSQA on the resource to set it active and then at the end of JOBB a trailer step added to do a PRSQD to deactive the resource. Or you can use automation to enter the PRSQA/PRSQD commands if you can be sure of the timing.
As always, please contact CA Technologies support for CA 7 if you have further questions.