Workers who work in a managerial or executive position are granted L-1A visas. Managerial and executive positions aren't limited to individuals in charge of major businesses or a large number of employees; they can also include managers of independent contractors. However, first-line supervisors are not commonly labeled as managers unless they supervise professional staff, therefore this classification does not apply to them.
A supervisor in charge of shifts of hourly employees at a factory, for example, would not be the best candidate for an L-1A visa because USCIS may claim that these production workers aren't professionals. Davie, an L1 Visa Lawyer, is the greatest and most trustworthy person to assist you.
