Improvement using plan-do-check-act and quality control tools: a case study in mobile phone manufacturing

In high-volume electronics assembly, rework destabilizes delivery performance, lowers productivity, and raises the cost of subpar quality. This research details an organized Plan-Do-Check-Act (PDCA) improvement initiative that was carried out in a high-volume manufacturing facility on mobile phone assembly lines. Dominant rework drivers were identified using Pareto analysis based on a month's worth of rework records. They were then verified by cross-functional review, shop floor observation, and a cause-and-effect (fishbone) diagram. Interventions concentrated on two areas: (i) workstation-level standardization and training to lower failures linked to handling and soldering, and (ii) crucial component quality governance (supplier containment and tightened incoming quality control for LCD, keypad, and PCBA-related issues). Rework decreased from 20188 to 10 976 units (−45.63%) during the next month, according to a before-and-after analysis. Results are presented as normalized rework rates (per 1000 units produced), which is a 25.81% reduction, to improve comparability and internal validity. When production exposure data are available, simple statistical tests and/or control-chart evidence are used to corroborate the findings. For high-volume assembly environments, the example offers transferable advice on defect prioritization, intervention traceability, and sustainment methods (control plan, KPI monitoring, and audit routines).