Appropriate port location selection is critical to achieve the competitiveness and effectiveness of transportation, distribution, and the entire global supply chain and to bolster the local, regional, and national economies. The objective of this study is to develop a new framework to select the optimal location for the offshore port. The framework includes multicriteria decision-making (MCDM) methods along with experts’ judgment and a simulation-based model of the facility's performance. At first, the Rough Analytical Hierarchy Process (AHP) and Rough Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) are utilized to preliminarily prioritize the alternative locations. After that, the port performance of selected locations with their corresponding transport distances over the lifetime of the project is assessed via simulation-based experiments. Finally, life cycle costing (LCC) is performed for the final assessment of each port location. The proposed framework is examined for Cua Lo Petrol Base in Vietnam as a case study. The result of the study indicated that the optimal location unveiled by simulation experiments is not always the first-ranking location based on the MCDM. The outcome of this study will assist port and marine investors to find the optimum location for port planning in terms of technical and economic viewpoints.