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 had 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 decision with objective evidence that the candidate is qualified.