Multiobjective single machine scheduling with nontraditional requirements

Many scheduling problems encountered in practice must address requirements that are not found in the literature like maximizing the number of jobs that have a particular color. These nontraditional requirements are sometimes an objective as when the desirability of a schedule increases with the number of jobs of the same color that are scheduled consecutively. Other times, the requirements take the form of constraints as in cases where it is forbidden to have more than two consecutive jobs with a particular color. To complicate the situation, most real scheduling problems are multiobjective. This research centers on bicriteria scheduling with nontraditional requirements using an experimental approach and a Random Keys Genetic Algorithm to find Pareto optimal solutions. We address both traditional and nontraditional requirements in a single machine job shop with 20–50 jobs.