A Comprehensine Examination of Coarse Aggregate Selection Utilized in Concrete Production Across Several Ready-Mix Companies. Case Study on Lombok Island

The increasing demand for ready-mix concrete in Lombok Island has intensified the need for high-quality coarse aggregates capable of ensuring concrete strength, durability, and long-term performance. However, variations in aggregate characteristics, mining permit compliance, and operational conditions among quarry sources complicate the selection process. This study aims to determine the most suitable coarse aggregate source for ready-mix concrete production by integrating the Analytic Network Process (ANP) and the Technique for Order Preference by Similarity to Ideal Solution (TOPSIS), followed by validation through laboratory testing. Primary data were collected through field observations, expert interviews, and pairwise comparison questionnaires involving directors, production managers, and quality control personnel from five ready-mix concrete companies on Lombok Island. The ANP method was employed to determine the relative importance of decision criteria and sub-criteria, while TOPSIS was used to rank five alternative aggregate sources. Laboratory tests, including gradation, abrasion resistance, specific gravity, and silt content analyses, were conducted to verify the decision-making results. The findings indicate that technical criteria (0.445) and mining permit criteria (0.419) are the most influential factors in aggregate selection. TOPSIS ranked Pringgabaya as the best alternative (0.6169), followed by Sembelia (0.5878), while Bilelando obtained the lowest preference value. Laboratory testing generally confirmed the decision-making results, particularly for gradation, specific gravity, and silt content. The study concludes that the integrated ANP–TOPSIS approach provides a reliable and comprehensive decision-support framework for selecting coarse aggregates and can improve material selection practices in ready-mix concrete production.