Kekosongan obat di Instalasi Farmasi Charitas Hospital Palembang mengganggu operasional pelayanan dan mengancam keselamatan pasien, dengan kejadian penundaan resep mencapai 1,16% di Farmasi Rawat Jalan dan sekitar 50% pasien tidak kembali mengambil obat. Penelitian ini bertujuan untuk menganalisis dampak implementasi Lean Six Sigma terhadap penurunan kejadian kekosongan obat dan mempertahankan nilai Inventory Turn Over Ratio (ITOR). Desain penelitian menggunakan action research dengan membandingkan periode sebelum implementasi (Januari–April 2026) dan sesudah implementasi (Mei 2026), menerapkan metodologi Lean Six Sigma melalui tahapan Define, Measure, Analyze, Improve, dan Control (DMAIC). Hasil penelitian menunjukkan bahwa Farmasi Rawat Inap berhasil mempertahankan persentase penundaan resep di bawah 0,1% (0,07% pada Mei 2026) dengan nilai ITOR stabil di 1,85, sementara Farmasi Rawat Jalan mengalami peningkatan penundaan menjadi 1,16% dengan nilai ITOR terkoreksi ke 1,62. Tiga solusi perbaikan yang diimplementasikan adalah formulasi perencanaan berbasis Excel dengan perhitungan safety stock dan reorder point, edukasi budaya kerja anti-double click, dan upgrade spesifikasi komputer. Kesimpulannya, intervensi jangka pendek yang diterapkan belum optimal mengatasi masalah kekosongan obat di Farmasi Rawat Jalan yang memiliki permintaan dinamis, namun berhasil menjaga keseimbangan antara efisiensi biaya modal kerja dan ketersediaan obat untuk pelayanan pasien. Penelitian ini merekomendasikan kustomisasi sistem informasi farmasi (SIRS) secara permanen, integrasi dasbor pengadaan, dan penguatan hubungan vendor melalui Service Level Agreement (SLA) untuk mencapai perbaikan berkelanjutan.

Drug stock-out at Charitas Hospital Palembang's Pharmacy Department disrupts service operations and threatens patient safety, with prescription delay incidents reaching 1.16% in Outpatient Pharmacy and approximately 50% of patients not returning to purchase medications. This research aims to analyze the impact of Lean Six Sigma implementation on reducing drug stock-out incidents and maintaining Inventory Turn Over Ratio (ITOR) values. The study employs an action research design comparing pre-implementation (January–April 2026) and post-implementation (May 2026) periods, applying Lean Six Sigma methodology through Define, Measure, Analyze, Improve, and Control (DMAIC) phases. Results showed that Inpatient Pharmacy successfully maintained prescription delay rates below 0.1% (0.07% in May 2026) with stable ITOR at 1.85, while Outpatient Pharmacy experienced increased delays to 1.16% with ITOR corrected to 1.62. Three improvement solutions implemented were Excel-based planning formulation incorporating safety stock and reorder point calculations, anti-double click work culture education, and computer specification upgrades. In conclusion, short-term interventions proved suboptimal for addressing drug stock-out in Outpatient Pharmacy with highly dynamic demand, but successfully maintained balance between working capital efficiency and drug availability for patient care. This research recommends permanent pharmacy information system (SIRS) customization, integrated procurement dashboard implementation, and strengthened vendor relationships through Service Level Agreements (SLA) to achieve sustainable improvements.