This study examines the implications of considering additive manufacturing (AM) machines in scheduling approaches and evaluates the relationship to well-known scheduling problems on batch processing machines. To this end, we first analyze AM technologies and derive ways to model the processing time of production jobs. We examine the impact of integrating AM-specific processing time models into scheduling problems. For this purpose, we present a mixed-integer programming model aiming to minimize makespan on unrelated parallel AM machines. Based on our findings, we integrate different variants to calculate processing times for this model and demonstrate the different influences on the scheduling tasks. To evaluate the performance of the model variants and their impacts on resulting schedules, we explore various instance settings. The results of our study highlight the benefits of explicitly incorporating AM features in model formulations to substantially improve makespan in AM production facilities.