In this paper, we deal with a U-shaped production line with multiple multi-function workers. Each worker takes charge of multiple machines. We consider two types of allocations of workers to machines, a separate allocation and a carousal allocation. In the separate allocation, each worker takes charge of a unique set of machines and therefore at each machine the same worker operates items in every cycle. In the carousel allocation, all workers take charge of all machines in the same order. The processing times of the machines, and the operation and walking times of the workers are assumed to be independent and identically distributed random variables. We examine the influence of the variances of these processing, operation and walking times upon the cycle times of these allocation models by simulation and experimental design. We also examine the influences of the buffer sizes and the number of items in these buffers upon the cycle time, if the U-shaped line has some buffers and some items in them.
