federal grantees and federal contractors must have an affirmative action plan and EEO statement in their policies, according to Executive Order 11246, the Vietnam Era Veterans Readjustment Assistance Act of 1974, and the Rehabilitation Act of 1973; these federal requirements are enforced by the DOL's Office of Federal Contract Compliance Programs
an employer may be ordered by a court or an administrative agency to adopt such policies
employers may adopt such policies on their own - however, be careful about "reverse discrimination" - basing employment decisions on minority status alone is very risky
affirmative action can be as simple as advertising job openings in media that reach diverse markets and in ways that are designed to bring word of openings and promotional opportunities to the broadest possible group of potential applicants - the goal is to cast as wide a net as possible