1
                           general:: 
                            Phrase(s): on the job 
working; doing what one is expected to do.  •  I’m always on the job when I should be.  •  I can depend on my furnace to be on the job day and night.
                        
                        
 
                        
                            McGrawhill's American Idioms And Phrasal Verbs
                        
                        
                    
                    
                        2
                           general:: 
                            1. At work, busy, as in We've got three men on the job. [Late 1800s] 2. Paying close attention, alert, as in Trust Jim to find out the details? he's always on the job.
                        
                        
 
                        
                            American Heritage Idioms