Mätning av det omätta: En processbaserad studie av materialspill inom kundorderstyrd plåttillverkning

Sammanfattning

Purpose – The purpose of this study was to apply the Define, Measure, Analyse, Improve, Control(DMAIC) framework as a structured approach for identifying and analysing scrap generation at theprocess-level in make-to-order (MTO) sheet metal production, and to evaluate how process-levelmeasurement can serve as a foundation for structured scrap reduction. Methodology – A single-site case study conducted at an air handling unit (AHU) manufacturer insouthern Sweden, using a concurrent mixed-method approach, combining structured observations, semi-structured interviews, enterprise resource planning (ERP) extraction and manual scrap bin weighingacross the DMAIC phases, with the Control phase excluded due to the time constraints. Findings – A combined ERP extraction and manual weighing approach successfully established aprocess-level scrap baseline where none previously existed. The punching stage was the dominant scrapcontributor, with coil width mismatch as the primary root cause. A significant measurement gap wasidentified at the blank removal station, which contributed to 19% of total weighed scrap despite notbeing visible in the ERP data. Four improvement proposals were developed spanning kaizen- andkaikaku-type interventions. Implications – The study demonstrates that process-level scrap measurement is achievable low-automation MTO environments when the measurement approach is designed around actual dataavailability. It contributes to the applied DMAIC literature by showing that the Measure phase musttreat measurement system design as an active output rather than a precondition.Limitations – Single case study conducted over one academic semester. Manual weighing carriedhuman-dependent variability, and proposed improvements were not implemented or validated.