Inability of an individual or a group to perform the given tasks up to the established standards. http://www.businessdictionary.com/definition/deficiency-performance.html.
TSA Requirements. The TSA requires that adult passengers ages 18 and older show valid photo ID at the security checkpoint. Children, however, are not required to present such identification. This does not mean, however, that children will be able to fly without it.
Children ages 12 and younger can accompany an adult with TSA PreCheck or Global Entry through the quicker airport security lines without having their own PreCheck clearance. However, Global Entry does not allow children to go through expedited customs screening without their own enrollment in the program.