"The purpose of this updated guidebook is to promote data-driven mission-impact-based analysis and assessment methods for cybersecurity test and evaluation (T&E) and to support assessment of cybersecurity, system cyber survivability, and operational resilience within a mission context by encouraging planning for tighter integration with traditional system T&E. Cybersecurity T&E starts at acquisition initiation and continues throughout the entire life cycle." [Guidebook pg. 1]