Implementasi Sistem Penguncian Dolly Seat Delivery untuk Mengurangi Defect Menggunakan Metode PDCA dan Kaizen di Suatu Perusahaan Manufaktur Kabupaten Bekasi

Abstract

The rapid development of the automotive industry requires fulfilling high-quality standards and minimizing defects in every production line. This study aims to analyze and resolve quality issues, specifically the alignment defect (known as defect jomplang) and its secondary defect of scratches (scratch) on the seat delivery component at an automotive component manufacturing company in Bekasi Regency. The improvement method employed is the Plan-Do-Check-Action (PDCA) cycle integrated with the Kaizen philosophy of continuous improvement. Initial analysis revealed that the alignment defect dominated by 59.00% of the total product rejects during the June-July 2025 period, with an average operational defect rate of 0.41%, exceeding the company's internal tolerance limit of 0.15%. Through a Fishbone Diagram, it was identified that the root cause was mechanical wear in the dolly locking system (exhibiting a 3–5 mm gap clearance) and the absence of mechanical checking procedures prior to delivery. Corrective actions included modifying the locking design to a magnetic pin system equipped with High-Density Urethane cushions to achieve a Zero Gap condition, alongside implementing updated Standard Operating Procedures (SOP) via the 'Click & Shake' test. Post-implementation in August 2025, the defect rate dropped sharply to 0.059%, which successfully achieved the research target (0.10%) and outperformed the company's quality Key Performance Indicators (KPI). This study demonstrates that the consistent integration of PDCA and Kaizen methods can effectively stabilize internal logistical processes and sustainably enhance manufacturing quality efficiency.