This document discusses a study that aimed to identify key factors affecting hospital performance. The researchers conducted qualitative interviews and expert panels to detect factors associated with performance. They then used fuzzy logic and DEMATEL (Decision Making Trial and Evaluation Laboratory) techniques to quantitatively measure direct and indirect relationships between the factors. The study was conducted at Tehran Heart Center, a major cardiac hospital in Iran that has achieved high performance levels over many years based on statistical, qualitative, and accessibility indicators. The results could help better plan for hospital performance improvement.