Before recalling a data set, DFSMShsm will check if a class transition was missed while that data set was migrating. If a class transition was missed, then DFSMShsm will run the ACS routines with ACS environment SPMGCLTR to determine any new SMS construct names. Using the newly retrieved management class name, DFSMShsm will repeat the check to see if a class transition was missed, until the appropriate management and storage classes and storage group(s) are finally found. These new management class, storage class, and storage group(s) are then used for the RECALL.