The competitive civil-service system is designed to give candidates fair and equal treatment and to ensure that federal applicants are hired based on objective criteria. Hiring has to be based solely on a candidate's knowledge, skills, and abilities (which you'll sometimes see abbreviated as ksa), and not on external factors such as race, religion, sex, and so on. Whereas employers in the private sector can hire employees for subjective reasons, federal employers must be able to justify their decision with objective evidence that the candidate is qualified. The federal government's practice of hiring on the basis of ksa frequently results in the hiring of employees