The original labor certification process, used exclusively up until about 1998, involved a lengthy interview process, whereby instructions were provided after filing the case as to how the employer was to go about recruiting for the position. After complying with those instructions, the employer needed to persuasively argue why any US applicants for the position were unqualified - otherwise the position would be denied. Beginning in 1998, a more streamlined approach called Reduction in Recruitment (RIR) was introduced. Under RIR, the sequence of events was reversed: the employer first did the recruiting, and then filed the case with evidence that no minimally qualified US workers could be found.
RIR tended to speed processing times up somewhat, so that labor certification times which were previously measured in years began to be measured in months. Both regular and RIR labor certification involved filing first with the Department of Labor for the individual state where the job was located (the individual state presumably being most familiar with local labor market conditions) and then, if approved at the state level, the case was then transferred to the federal Department of Labor for final approval.