This is an option open to employers wanting to hire workers temporarily, but on a long-term basis. When the employer wants to hire an individual permanently, they must go through the green card petition process, which may take many years to resolve. The first step in the process is typically labor certification, which means the employer must prove there are no qualified US workers available for the position(s).
If there are even minimally qualified United States citizens who can fill the position, the employer may not offer the position to a foreign worker on a permanent basis. Many employers consider this to be inconvenient. This used to be an exhaustively lengthy process that has evolved into a more streamlined process: the electronic labor certification system (PERM). PERM is an acronym for Program Electronic Review Management. The goal of the process it the certification of workers in less than 60 days.
Labor certification remains a contentious issue. Some say it identifies skilled workers needed by the US labor market that cannot be found locally. Others indicate employers hire non-citizens and then tailor the job to their skills.