Silitonga, R.Y., Bahagia, S.N., Simatupang, T. and Siswanto, J. 2013. Modeling the Competitiveness of Indonesian Palm Oil Industry: A Conceptual Model Using Hierarchical Multi-Level System Approach. Jurnal Teknik Industri: Jurnal Keilmuan dan Aplikasi Teknik Industri. 15, 2 (Dec. 2013), 103-110. DOI:https://doi.org/10.9744/jti.15.2.103-110.