Ensuring software quality is one of the key challenges associated with the development of automotive embedded systems. Software architecture plays a pivotal role in realizing functional and non-functional requirements for automotive embedded systems. Software architecture is a work-product of the early stages of software development. The design errors introduced at the early stages of development will increase cost of rework. Hence, an early evaluation of software architecture is important.PERSIST (Powertrain control architecture Enabling Reusable Software development for Intelligent System Tailoring) is a model-based software product line approach which focuses on cross-project standardization of powertrain software. The product line is characterized by common design guidelines and adherence to industry standards like ISO 25010, AUTOSAR and ISO 26262. This paper shows a systematic approach to ensure objective, early and repeated analysis of software architecture for the PERSIST product line using metrics. The systematic approach for architecture metrics involves the definition, implementation, measurement and, evaluation of the metrics for hybrid control unit software. With a new approach of architecture-driven development, this paper demonstrates how an early evaluation of the software architecture helps to frontload development efforts and improves software quality.