Fix the qualifying year and the technical evidence first, file next, and only then commit to a commissioning date with the American affiliate or its customers.
Do not sell an installation date against an unfiled petition
Hypothetical example: Commissioning work is usually scheduled against a customer's own construction or seasonal calendar, which creates pressure to promise dates early. Resist it until the petition is filed. The preparation is unpredictable: locating original development records, obtaining redaction approval, and reconstructing the employment chronology can each add weeks, and the one continuous qualifying year must fall inside the three years immediately before filing.
USCIS processing follows, compressible by premium processing but not removable. If part of the assignment will occur at a customer's facility, the contract governing supervision and control should exist before filing rather than being drafted afterwards to match the petition. Finally, count backwards from the five-year L-1B maximum.
A transferee who has already spent two years in the United States in L status has three left, and a phased multi-year commissioning programme may not fit inside them.