Bi

To solve the scheduling problem of a single hoist with processing-time-window constraints considering buffer-setting, we consider bi-objective scheduling which makes trade-offs between the cycle time and the hoist travel distance. First, a bi-objective mixed-integer programming model is constructed for the basic line without considering buffer-setting. In order to improve the throughput of the basic line, a transform method with buffer-setting is put forward. Based on the basic line model, a subsection searching ε-constraint method which combines the transform method is introduced to solve the bi-objective mixed-integer programming model. Experimental results both on benchmark instances and on randomly generated instances indicate that the proposed approach is efficient and buffers can improve the throughputs