Abstract: In hybrid flow shop scheduling, generally, the object of optimization is to get the makespan minimized, not considering differences of the same facilities’ processing time during the same stage, which is disadvantageous for machines’ maintenance and management and is unfair for manipulators. This paper formulates a load balancing model, sets forth a new immune algorithm for solving it, and compares two results for subjection and non-subjection to load balancing, and the computed result shows that the algorithm is an effective tool for such problems.

Key words: hybrid flow shop, production scheduling, load balancing, immune algorithm