Comparing security engineering process and life cycle models (e.g. the IATF or the NIST SP-800-30 RMF) to systems engineering process and life cycle models is, on the surface, easy. The similarities appear evident, with obvious corollaries between life cycle stages, entry and exit criteria, tasks to be performed, and measures of success. Security engineering is however, dramatically different in purpose; focused more on risk management than on creation of either system or process. This paper will present the similarities and the obvious differences between systems engineering and security engineering, and will discuss the nature and the challenges of the major categories of professionals in each discipline. Life cycle models, maturity models, engineering processes, and body of knowledge will be compared and contrasted.