ABSTRACT Grillsa MSME is a culinary business facing problems in its raw material storage system due to the suboptimal implementation of the First In First Out (FIFO) method, which potentially increases the risk of material reject caused by the deterioration of raw material quality during storage. This study aims to identify the condition of the raw material storage system, analyze the factors causing material reject, and implement the FIFO method as an effort to minimize material reject at Grillsa MSME. The research employed a descriptive quantitative method with a Plan-Do-Check-Action (PDCA) approach. Data were collected through observation, interviews, and documentation, while Pareto Diagram and Fishbone Diagram analyses were used to identify the dominant types and root causes of rejects. The Pareto analysis revealed that the highest reject rate was caused by meat discoloration, accounting for 71% of total rejects. Fishbone analysis indicated that the main causes were the lack of optimal FIFO implementation, the absence of shelf-life identification, and disorganized storage conditions. Improvement actions were carried out through raw material grouping based on type, storage layout rearrangement, color labeling for shelf-life identification, and the development of standard operating procedures (SOPs) for raw material storage. The implementation of FIFO resulted in a more organized storage system, easier identification and retrieval of materials according to their arrival sequence, and a reduced risk of material reject. Therefore, the FIFO method proved effective in improving raw material inventory management and maintaining raw material quality during storage. ABSTRAK UMKM Grillsa merupakan usaha kuliner yang menghadapi permasalahan pada sistem penyimpanan bahan baku yang belum menerapkan metode First In First Out (FIFO) secara optimal sehingga berpotensi meningkatkan risiko material reject akibat penurunan kualitas bahan baku selama penyimpanan. Penelitian ini bertujuan untuk mengidentifikasi kondisi sistem penyimpanan bahan baku, menganalisis faktor-faktor penyebab material reject, serta menerapkan metode FIFO sebagai upaya meminimalisir material reject di UMKM Grillsa. Penelitian menggunakan metode kuantitatif deskriptif dengan pendekatan Plan-Do-Check-Action (PDCA). Pengumpulan data dilakukan melalui observasi, wawancara, dan dokumentasi, sedangkan analisis data menggunakan Diagram Pareto dan Diagram Fishbone untuk mengidentifikasi jenis serta akar penyebab reject yang dominan. Hasil analisis Pareto menunjukkan bahwa reject tertinggi terjadi pada daging yang mengalami perubahan warna dengan persentase sebesar 71%. Analisis Fishbone menunjukkan bahwa penyebab utama material reject meliputi belum diterapkannya FIFO secara optimal, tidak adanya identifikasi masa simpan bahan baku, serta kondisi penyimpanan yang belum teratur. Tindakan perbaikan dilakukan melalui pengelompokan bahan baku berdasarkan jenis, penataan ulang layout penyimpanan, penggunaan label warna sebagai identifikasi masa simpan, dan penyusunan standar operasional prosedur (SOP) penyimpanan bahan baku. Hasil penerapan FIFO menunjukkan peningkatan keteraturan sistem penyimpanan, kemudahan dalam identifikasi dan pengambilan bahan baku sesuai urutan kedatangan, serta berkurangnya risiko material reject. Dengan demikian, metode FIFO terbukti efektif dalam mendukung pengelolaan persediaan bahan baku dan menjaga kualitas bahan baku selama proses penyimpanan.