Serial production lines with unreliable machines and limited repair

The output of an N-stage line with unlimited buffer space between stages is a function of the number of repair crews assigned to the line and the failure and repair rates of the individual stages. Rules for assigning crews that are examined include preference for slow stages and randomization. It is shown that appropriate randomization maximizes output in the 2 stage, 1 crew case. Furthermore, in a large system with slower stages having slower repair rates, the best way to dedicate repairmen is to assign one man to each slow stage in so far as possible and to pair remaining stages in combinations of slowest-fastest, next slowest-next fastest, etc.