In reply to SHRI12326:
The UVM has a phase approach. After starting run_test 8 main phases are executed in the following order
(1) build_phase
(2) connect_phase
(3) end_of_elaboration_phase
(4) start_of_simulation_phase
(5) run_phase
(6) extract_phase
(7) check_phase
(8) report_phase
You do not have to take care for these phases. They are all started automatically.
run_phase is where the simulation happens. It is th eonly phase which is consuming time.