A person’s executive functioning capability gradually develops from birth, to be mostly matured by the age of 12. The Comprehensive Executive Function Inventory TM (CEFI®) is a multi-rater behaviour scale used by practitioners to guide diagnosis and treatment of executive functioning disorders that inhibit clients from attaining their goals. Such functioning influences cognitive processes such as attention, emotional regulation, flexibility, inhibitory control, initiation, organisation, planning, self-monitoring, and working memory, all of which are necessary to engage in purposeful, goal-directed behaviours.