This thesis investigates the comparative effectiveness of projector-based and monitor-based visualization methods for manual assembly tasks within industrial contexts. The study employs a controlled experimental design, where twelve participants assemble a CEJN multi-X coupler using either monitor or projector mediated visual instructions. Key performance metrics (task completion time, error rate, and cognitive workload) are systematically evaluated. Results indicate that monitor-based visualizations support faster task completion and reduced perceived mental workload, while projector-based systems significantly minimize assembly errors, particularly in complex tasks. These findings highlight the context-dependent strengths of each visualization method and address a research gap in comparative assembly instruction modalities beyond traditional Augmented Reality (AR) and head-mounted display solutions. The study’s implications extend to manufacturing practices aiming to improve productivity, minimize errors, and align with principles of Industry 4.0 and sustainable production. The research further discusses the limitations of laboratory conditions, sample size, and the need for expanded future studies employing more diverse visualization technologies and real-world settings.