Healthcare systems face persistent challenges in delivering consistent service quality despite rapid technological transformation. Traditional Healthcare Service Quality (HCSQ) models treat quality dimensions descriptively and assume equal importance, limiting structured prioritization in technology-enabled settings. This study proposes a Relational Framework for HCSQ (RF-HCSQ) and Decision Support Tool (DST) integrating validated quality domains and Key Performance Indicators (KPIs) with hybrid multi-criteria weighting. A mixed-method approach combined expert interviews, a three-round Delphi validation, a practitioner survey (N=127), and a patient survey (N=206). Ten domains and 47 KPIs were validated and weighted via hybrid techniques integrating the Analytic Hierarchy Process (AHP), Arithmetic Mean aggregation, and Shannon entropy, while patient priorities were modeled using the Plackett-Luce method. Bootstrap resampling confirmed robustness. Findings identify Patient Safety as the most influential domain and Clinical Quality as the second, with Technology Impact functioning as an enabling rather than outcome-driving domain. A preliminary end-user evaluation (n=7) indicated that the DST supports structured prioritization and actionable performance review.