Abstrak Penelitian ini bertujuan untuk mengoptimalkan penjadwalan proyek konstruksi tangki penyimpanan minyak dan gas melalui pendekatan terintegrasi yang mengkombinasikan Critical Path Method (CPM), Gantt Chart, dan Resource Leveling. Studi ini menggunakan desain explanatory case study pada satu proyek konstruksi yang dilaksanakan oleh PT Bukaka Teknik Utama untuk Pertamina Hulu Sanga-Sanga. Data diperoleh dari dokumen proyek dan wawancara semi terstruktur dengan tim manajemen proyek. Analisis dilakukan melalui identifikasi jalur kritis, visualisasi jadwal, serta redistribusi tenaga kerja pada aktivitas non kritis. Hasil penelitian menunjukkan bahwa aktivitas Radiography Test for Shell Plate Thickness 8 merupakan aktivitas kritis utama yang mempengaruhi durasi proyek. Tanpa optimasi, proyek diproyeksikan mengalami keterlambatan selama 444 hari. Setelah penerapan resource leveling, jadwal proyek dapat dipercepat hingga 455 hari dengan penambahan sumber daya. Temuan ini membuktikan bahwa integrasi metode penjadwalan konvensional mampu meningkatkan kelayakan jadwal dan efisiensi pemanfaatan tenaga kerja secara signifikan. Kata kunci: Project scheduling, CPM, Gantt chart, Resource leveling, Oil and gas construction. Abstract This study aims to optimize project scheduling in an oil and gas storage tank construction project using an integrated approach combining the Critical Path Method (CPM), Gantt Chart, and resource leveling. An explanatory single case study design was applied to a project executed by PT Bukaka Teknik Utama for Pertamina Hulu Sanga-Sanga. Data were collected from project documents and semi structured interviews with project management personnel. The analysis involved critical path identification, schedule visualization, and manpower redistribution across non critical activities. The results indicate that the Radiography Test for Shell Plate Thickness 8 is the main critical activity influencing overall project duration. Without optimization, the project was projected to experience 444 day delay. After applying resource leveling, the project completion date was advanced by 455 days with additional resources. These findings demonstrate that integrating conventional scheduling tools can significantly improve schedule feasibility and workforce efficiency in complex construction projects. Keywords: Project scheduling, CPM, Gantt chart, Resource leveling, Oil and gas construction.