Before revision:  At every time step, the scheduler has the possibility either to test a job, by querying a processing time oracle , which reveals its processing time , and occupies one time unit on the schedule . Or the scheduler can execute a job, might it be previously tested or not .
After revision:  At every time step, the scheduler has the possibility either to test a job, by querying a processing time oracle , which reveals its processing time , and occupies one time unit on the schedule , therefore the algorithm must decide for which jobs it will call the processing time oracle .