This article introduces a novel Enterprise Performance Engineering Maturity Model (EPEMM) for transforming enterprise systems through advanced performance engineering methodologies. Unlike existing approaches, our framework synthesizes industry practices with empirical validation across multiple organizational contexts. Through extensive field research including surveys (n = 128), structured interviews (n = 42), and longitudinal case studies of Fortune 500 implementations, we demonstrate how the proposed EPEMM enables organizations to systematically advance their performance capabilities across five distinct maturity levels. Our comparative analysis reveals significant variations in effectiveness across industry sectors, with financial services achieving 43% greater improvement than manufacturing when implementing Level 4 practices. The research addresses critical gaps in current performance engineering literature by providing a reproducible methodology for capability assessment and progression, architectural reference models for implementation, and empirically-validated decision frameworks for practice selection. Our findings contribute to both theoretical understanding of performance engineering evolution and practical implementation guidance for organizations seeking performance excellence.