Abstract: To improve the scientificness and rationality of feeding buffer settings, in calculating the capacity of the feeding buffers, the distribution of non-bottleneck immediate predecessor operations should be considered. Also, the degree of bottleneck nonbottleneck operation risk should be distinguished. By using fuzzy theory, the buffering requirement of non-bottleneck immediate predecessor operations is calculated by considering some factors, such as process location weight, the degree of resource tensity, process complexity, and risk tolerance. Based on the buffer configuration and distribution of nonbottleneck immediate predecessor operations, a formula for calculating the capacity of a feeding buffer is deduced. The reasonableness of the proposed method is verified by an example. Result shows that the distribution of non-bottleneck immediate predecessor operations and risk tolerance have a significant influence on the capacity of a feeding buffer, and the latter is greater than the former.