,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18
reduce_execution_time 
precedence_constraint_change 
processor_speed_increase
period_change
priority_change
processor_number_increase 
delay_thread_execution 
reduce_preemption_delay 
deadline_increase 
reduce_self_suspension