I read Software Architecture Metrics: 10 Tips for Improving Architecture Quality.
Multiple authors discuss various perspectives on metrics related to software. As indicated by the subtitle, each chapter offers advice from different authors, and while the details are not deeply explored, it serves as a good starting point to understand the perspectives on architecture metrics.
Chapter 10, which introduces the GQM approach for defining metrics, left a strong impression on me personally.
In addition to the introduction of the fitness function presented in evolutionary architecture, some metrics regarding system quality are also introduced, which I found helpful.
