Single Batch Processing Machine Scheduling with Sequence-Dependent Setup Times and Multi-Material Parts in Additive Manufacturing

Additive manufacturing (AM) has been a breakthrough revolution in themanufacturing world due to the ability to economically print parts with highgeometric complexity, minimal vast and dissimilar materials in the sameprinting process. However, some problems arise with the usage ofmulti-materials in AM machines. This study aims to analyze the schedulingproblem of a single AM machine for printing multi-material parts. We developeda mathematical model for a single AM machine to directly minimize the makespanof a production schedule of multi-material parts and indirectly minimize thematerial changeovers. IBM ILOG CPLEX Optimization Studio (v12.10) is used forthe development stage of the model. Some numerical examples from AM literaturewere handled and solutions were gathered. Effects of material changeover costsfor the different numbers of materials were investigated. Results indicatedthat setup time depending on material changeoversbecomes a critical parameter for the minimization of makespan. Highernumbers of dissimilar materials increase the completion time of the schedule.While the developed model can be used for AM machines with different materialchangeover difficulties, it can also be used in the printing of parts that needto be uncontaminated finished products.</p