DMAIC sebagai Strategi Pengendalian Overflow Gudang: Studi Kasus Industri Otomotif

Abstract

This study discusses the problem of overflow in warehouse management which has an impact on decreasing operational efficiency and increasing logistics costs. The study was conducted at the warehouse of PT Toyota Motor Manufacturing Indonesia (TMMIN), a large-scale automotive company that implements a just-in-time production system. The method used is Six Sigma with the DMAIC (Define, Measure, Analyze, Improve, Control) approach to analyze and solve problems systematically and based on data. Data collection techniques include direct observation of the warehouse area, interviews with logistics personnel, and documentation of Stock On Hand (SOH) reports and the company's ERP-WMS system. Initial measurement results showed a material surplus of 4,574 units in the period from October to November 2024, with Gloves Comet CG801 as the largest contributor. Based on the fishbone diagram analysis and 5-Why technique, the main cause of the overflow was inaccuracy in demand forecasting and the suboptimal integration between the ERP and WMS systems. After implementing improvements, such as the preparation of new procurement SOPs, HR training, and information system integration, the amount of surplus Gloves Comet CG801 was successfully reduced by 40%. The logistics cost savings obtained reached Rp 9,811,750. Evaluation using P-Chart showed that the storage process was within the statistical control limits (in control), indicating post-intervention stability. The results of this study prove that the DMAIC approach can be used effectively in solving logistics problems and improving warehouse efficiency in the automotive industry in Indonesia.

Abstrak

Penelitian ini membahas permasalahan overflow dalam manajemen gudang yang berdampak pada menurunnya efisiensi operasional serta peningkatan biaya logistik. Studi dilakukan pada warehouse PT Toyota Motor Manufacturing Indonesia (TMMIN), perusahaan otomotif berskala besar yang menerapkan sistem produksi just-in-time. Metode yang digunakan adalah Six Sigma dengan pendekatan DMAIC (Define, Measure, Analyze, Improve, Control) untuk menganalisis dan menyelesaikan permasalahan secara sistematis dan berbasis data. Teknik pengumpulan data meliputi observasi langsung terhadap area gudang, wawancara dengan personel logistik, serta dokumentasi laporan Stock On Hand (SOH) dan sistem ERP–WMS perusahaan. Hasil pengukuran awal menunjukkan terjadinya surplus material sebesar 4.574 unit dalam periode Oktober hingga November 2024, dengan Gloves Comet CG801 sebagai penyumbang terbesar. Berdasarkan analisis fishbone diagram dan teknik 5-Why, penyebab utama overflow adalah ketidaktepatan dalam peramalan permintaan serta belum optimalnya integrasi antara sistem ERP dan WMS. Setelah implementasi perbaikan, seperti penyusunan SOP pengadaan baru, pelatihan SDM, serta integrasi sistem informasi, jumlah surplus Gloves Comet CG801 berhasil diturunkan sebesar 40%. Penghematan biaya logistik yang diperoleh mencapai Rp 9.811.750. Evaluasi menggunakan P-Chart menunjukkan bahwa proses penyimpanan telah berada dalam batas kendali statistik (in control), menandakan stabilitas pasca-intervensi. Hasil penelitian ini membuktikan bahwa pendekatan DMAIC dapat digunakan secara efektif dalam menyelesaikan masalah logistik dan meningkatkan efisiensi warehouse pada industri otomotif di Indonesia.