The chambers 212A, 212B which represent the bottleneck chambers, may have a “time” to next planned maintenance of 3000 and 12000 substrates, respectively, while the chambers 213A, {HEAD ~ 213B} may have {TAIL ~ times} corresponding to 2500 and 9000 substrates, respectively 
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The chambers 212A , 212B which represent the bottleneck chambers , may have a “ time ” to next planned maintenance of 3000 and 12000 substrates , respectively , while the chambers 213A , { HEAD ~ 213B } may have { TAIL ~ times } corresponding to 2500 and 9000 substrates , respectively
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