This book constitutes the refereed papers of the proceedings of the 8th International Conference on System Analysis and Modeling, SAM 2014, held in Valencia, Spain, in September 2014. The 18 full papers and the 3 short papers presented together with 2 keynotes were carefully reviewed and selected from 71 submissions. The contributions are organized in topical sections named: reuse; availability, safety and optimization; sequences and interactions; testing; metrics, constraints and repositories; and SDL and V&V.