Timeout Error in Microsoft Flow

Degree of Parallelism:
The number of loop iterations that can run at the same time, or in parallel.

In some scenarios if the number of child records is more , flow takes more time to complete. In my case, it took more than 4 minutes to process 100 records.
We can improve the flow performance by enabling ‘Concurrency Control’ and adjusting ‘Degree of parallelism’ settings of ‘Apply Each’ control.