You can specify NOSERIALIZE at the step level.
Typically, you use SERIALIZE in the UCF member to force the steps that are associated with a program (PROGRAM) or a DD statement (DDNAME) to run serially (not concurrently with other steps). To override the global nature of the UCF member, include the NOSERIALIZE JTL statement at the step level (after the EXEC PGM statement) of a job to instruct Job Optimizer to allow the step to run in parallel with other steps.
Because JTL statements override UCF statements, you can use the NOSERIALIZE JTL statement to override a SERIALIZE statement in the UCF member.
The NOSERIALIZE statement has the following syntax: