This model is "a structured progression of increased unit readiness over time, resulting in recurring periods of availability of trained, ready, and cohesive units prepared for operational deployment in support of geographic Combatant Commander requirements". ARFORGEN was replaced by the Sustainable Readiness Model (SRM) in 2017. In 2016 the Chief of Staff of the Army identified the objective of a sustainable readiness process as over 66 percent of the Active Army in combat ready state at any time; in 2019 the readiness objective of the National Guard and Army Reserve units was set to be 33 percent; Total Army readiness for deployment was 40 percent in 2019.