Update Standard Cost - Specific Item - Waiting on another cost update

When multiple Update Standard Costs concurrent program is submitted with specific item option.
It has been noticed that some of the running program log file states, it is waiting for another cost update.

CMCICU-0001 : Initializing control structure
Waiting on another cost update (request_id=97025482, org_id=100)
Waiting on another cost update (request_id=97025483, org_id=100)
Waiting on another cost update (request_id=97025485, org_id=100)
Waiting on another cost update (request_id=97025487, org_id=100)
.....

What actually is the program waiting for?

Thanks,
Nataraja Suthan,