Controlling Material Mismatch in Stamping through Total Quality Management and the PDCA Approach

Abstract

Material mismatch in stamping can trigger defects, rework, scrap, and productivity loss because incorrect material directly affects forming quality and downstream stability. This study evaluates Total Quality Management implemented through the Plan-Do-Check-Act cycle to control material-usage errors on machine S1 in a stamping company. A case-study design was used by combining January 2025 baseline records, March 2025 post-improvement records, direct observation, Pareto analysis, root-cause analysis, and 5W1H action planning. Before improvement, production reached 500,560 pcs with 8,490 reject pieces and a 1.6961% reject rate. After corrective actions and standardization, production reached 418,886 pcs with 2,235 reject pieces and a 0.5336% reject rate. Total reject declined by 73.67%, while the material-mismatch category decreased from 5,360 pcs to zero. The findings confirm that clear material identification, verification checkpoints, operator discipline, and standard work effectively prevent dominant stamping defects.