This study presents an innovative approach to evaluating efficiency by utilizing the Grey Slack-Based Measure (G-SBM) model, an advanced variant of Data Envelopment Analysis (DEA) designed to address environments characterized by high uncertainty and limited data. Incorporating interval grey numbers, the G-SBM model was applied to olive plantations in the Coquimbo region, Chile, in combination with the multi-criteria Grey MOORA method. This integrated methodology facilitates strategic decision-making by identifying both high-efficiency lots and those in need of improvement. The results highlight the critical importance of effective management practices in drought-prone regions, emphasizing the role of operational consistency in overall efficiency. Notably, the most efficient lots employed ecological management strategies, yet substantial efficiency disparities were observed, underscoring the necessity for a balanced management approach. Areas for improvement include under- irrigated lots and those relying on less productive pollinator varieties. This research not only demonstrates the applicability of the G-SBM model in uncertain contexts but also stresses the significance of selecting well-targeted and minimally correlated variables for a more robust and comprehensive analysis.