1. A powder metal (PM) manufacturing line produces bushing in three steps, compaction, sinter-harden, and rough/O?nish turn, which are accomplished at three single machine stations with average processing times of 12, 10 and 6 minutes, respectively. However, while compaction and sinter-harden are dedicated to the bushing line, the rough/O?nish turn station also processes bearings from another line; the average processing time for bearings are 14 minutes.
1. (a) If the production volume of bushings and bearings are the same, what is the bottleneck of the PM line?
2. (b) If the volume of bearings is 3 times that of the volume of bushings, what is the bottleneck of the PM line?