Free Up-gradation should be given at the time for chart is made (in all the trains if seats are available and train is running empty) even if there are seats available in 2S, CC, SL, 3A, 2A & 1A, i.e. if seats are available in 2A & 3A, few 3A passengers should be upgraded to 2A seats at the time of chart is made. same for 2S ----> CC, SL -----> 3A/2A/1A .......... 3A -----> 2A/1A ............. 2A ---> 1A