A conveyor system consists of equally-spaced hooks passing before a number of work stations. The work-pieces (units) are processed by the first available work station, after which they are transferred to a separate system. When the processing times are independently and exponentially distributed, distributions of the inter-arrival times of units at the work stations are found and it is shown that the incidence of missed units is minimized if the operatives are placed in descending order of work rate along the conveyor.