Jon & Simon 
SysML for Systems Engineering [PDF ebook] 
A model-based approach

This new edition of this popular text has been fully updated to reflect Sys ML 1.3, the latest version of the standard, and the discussion has been extended to show the power of Sys ML as a tool for systems engineering in an MBSE context. Beginning with a thorough introduction to the concepts behind MBSE, and the theoretical aspects and syntax of Sys ML, the book then describes how to implement Sys ML and MBSE in an organisation, and how to model real projects effectively and efficiently, illustrated using an extensive case study.