Numerical flexibility can also be achieved inside the company. In this case it is called
internal numerical flexibility.
"Numerical flexibility, which largely overlaps with external flexibility, refers to adjustments in the number of persons employed, downsizing and outsourcing where necessary."
(International Labour Organization (ILO),
Impact of flexible labour market arrangements in the machinery electrical and electronic industries,
Report for discussion at the Tripartite Meeting on the Impact of Flexible labour market Arrangements in the Machinery, Electrical and Electronic Industries, Geneva, 1999, visited 2010-28-09)