An analysis and evaluation methodology for rework impact in yacht outfitting

This thesis investigates the impact of rework activities that occur during yacht outfitting processes and develops a structured methodology for their systematic evaluation. Rework, defined as the need to repeat or modify a completed or almost completed task due to design inconsistencies, production errors, or coordination failures, represents a major source of inefficiency in project-based manufacturing systems such as shipbuilding. To address this issue, the study examines the outfitting phase of a 24-meter motor yacht, within which 22 rework cases were identified and analyzed over a 23-week production period. Each case was classified according to main production domains, such as equipment installation, piping, electrical systems, interior outfitting, and painting, and evaluated through cost-based and qualitative analyses. Parameters such as initial and rework labor cost, material reuse ratio, causal origin, and environmental influence were systematically assessed. The findings reveal that the most frequent and costly rework cases occur in piping, interior, and equipment-related operations, where coordination among disciplines is most critical. The results also demonstrate that a lack of integration between design, planning, and on-site execution significantly increases rework occurrence, disrupting production flow and efficiency. The proposed methodological framework integrates quantitative cost evaluation with qualitative assessment of organizational and technical factors, providing a replicable tool for future studies and industrial applications. Overall, the research highlights the multifaceted impact of rework in yacht outfitting, emphasizing its economic and managerial dimensions, and proposes improvement strategies aimed at enhancing production quality, planning accuracy, and cross-departmental coordination within the shipbuilding industry.