Expect the corporate and payroll work to dominate. Establishing the ownership chain and the qualifying year commonly takes longer than the adjudication that follows it.
Everything slow happens before the filing
Published processing times govern the filing and they change, so check them when the file is nearly ready rather than at the beginning. The preparation is the part to plan around. Reconstructing an ownership chain across related companies, obtaining share registers and resolutions, and confirming which entity employed the manager in each month is weeks of work involving an accountant and often a corporate lawyer. Incorporating and funding the U.S. subsidiary, signing a lease and opening banking has its own schedule set by third parties who do not share your urgency. Only then can the petition be drafted honestly. Build backwards from the date the U.S. operation must begin trading, allow for a request for further evidence, and put the twelve-month extension review in the calendar the day the first petition is filed.
L-1A still requires one continuous year of managerial or executive employment abroad in the preceding three, a qualifying parent, branch, subsidiary or affiliate relationship with continuing foreign operations, and a proposed position that is chiefly managerial or executive.