Pemerintah Indonesia, melalui Instruksi Presiden No. 3 Tahun 2003, memulai transformasi menuju e-government dengan menginisiasi Proyek Government Financial Management and Revenue Administration Project (GFMRAP). Salah satu perubahan terbesar dari proyek ini adalah implementasi Sistem Anggaran dan Perbendaharaan Negara (SPAN), yang mengadopsi aplikasi Enterprise Resource Planning (ERP). SPAN bertujuan meningkatkan akuntabilitas, transparansi, efisiensi, dan efektivitas pengelolaan keuangan negara. Dalam proses ini, SPAN pertama kali diterapkan pada tahun 2014 dan mencapai implementasi penuh pada tahun 2015. Meskipun demikian, tantangan dan risiko kritis masih muncul dalam tahap pasca-implementasi, termasuk kebutuhan untuk pemutakhiran sistem guna memastikan keberlanjutan dan keandalan operasional. Penelitian ini bertujuan untuk mengidentifikasi dan melakukan pemeringkatan faktor-faktor kunci yang mendukung kesuksesan pemutakhiran aplikasi SPAN, serta memberikan rekomendasi strategis berdasarkan faktor kunci tersebut. Penelitian menggunakan pendekatan mixed methods dengan studi kasus. Identifikasi faktor kunci dilakukan melalui Thematic Analysis (TA) terhadap data wawancara dan mencapai konsensus melalui Fuzzy Delphi Method (FDM). Sebanyak 24 faktor kunci berhasil diidentifikasi. Selanjutnya, Analytical Hierarchy Process (AHP) digunakan untuk menentukan prioritas dan bobot faktor-faktor tersebut. Hasil pemeringkatan menunjukkan bahwa faktor Top Management Commitment and Support memiliki bobot tertinggi, diikuti oleh faktor Testing and Quality Assurance dan Dedicated Development and Testing Environment. Berdasarkan hasil pemeringkatan, rekomendasi strategis disusun untuk mendukung keberhasilan pemutakhiran aplikasi SPAN. Penelitian ini memberikan kontribusi pada literatur faktor kunci kesuksesan pemutakhiran ERP di sektor pemerintahan.

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The Indonesian government, through Presidential Instruction No. 3 of 2003, initiated its transformation toward e-government by launching the Government Financial Management and Revenue Administration Project (GFMRAP). One of the most significant changes resulting from this project was the implementation of the State Budget and Treasury System (SPAN), which adopts Enterprise Resource Planning (ERP) applications. SPAN aims to enhance accountability, transparency, efficiency, and effectiveness in managing national finances. Initially implemented in 2014 and fully operational by 2015, SPAN continues to face critical challenges and risks in its post-implementation phase, including the need for system updates to ensure operational sustainability and reliability. This research aims to identify and rank the key success factors for SPAN's system upgrade while providing strategic recommendations based on these factors. The study employs a mixed-methods approach using a case study design. Key factors were identified through Thematic Analysis (TA) of interview data and validated through a consensus-building process using the Fuzzy Delphi Method (FDM). A total of 24 key factors were successfully identified. Subsequently, the Analytical Hierarchy Process (AHP) was utilized to determine the prioritization and weighting of these factors. The ranking results indicate that Top Management Commitment and Support holds the highest weight, followed by Testing and Quality Assurance and Dedicated Development and Testing Environment. Based on these rankings, strategic recommendations were developed to support the successful upgrade of SPAN. This study contributes to the literature on key success factors for ERP system upgrades in the government sector.