Thus, in {TAIL ~ order} to synchronize a down time of the tool in step 1{HEAD ~ , i.e., a down time} of the chamber 211A, the processing of the 6000 substrates has to be redistributed so as to process 4000 substrates in the chamber 211A and process 2000 substrates in the chamber 211B. Thus, a corresponding percentage for supplying substrates to step 1 will be two thirds for the chamber 211A and one third for the chamber 211B 