Abstract
A systematic method has been proposed, in previous paper, to allocate human operators to machine tools and to determine machining schedules considering statistical distributions of machining times. It was assumed that the processing times executed by the human operators are represented by random variables according to normal distributions, in the previous paper. However, normal distribution cannot express distributions of machining time enough e.g. case that probabilities of delay are larger than that of earliness. A new method is proposed, in this paper, to assign human operators to machine tools and to determine machining schedules considering statistical distributions of processing times under the assumption that the processing times executed by the human operators are represented by random variables according to beta distributions.