The US army uses a network optimization model to designate career fields for officers

In 1999, the United States Army instituted a new career-progression pattern for its officers. This pattern assigns, or designates, Army officers to specialized roles in which they must serve. Such roles include, for example, foreign area officer and operations research analyst. Manually designating officers into these roles under the new system is impossible because the problem is very large. We developed a network-optimization model, the career-field designation model, that makes these designations in minutes on a personal computer. The US Army has used this system four times since June 2001 to designate a total of approximately 10,500 officers and expects to continue to use the model to designate about 1,500 officers each year.