Not until the letter, the credential and the admission route have been confirmed. A port-of-entry decision is made on the day of application; a USCIS petition has its own processing time. Both are outcomes, not schedule entries.
How to sequence it
Work backward from the day the U.S. plant needs the engineer on site. Reserve time for the transcript to arrive, for the U.S.
entity to sign a corrected letter, and for the household to settle the spouse's plan. If the port-of-entry route is chosen, understand that the applicant may be refused that day and should not have sold a car or ended a lease in Saint-Augustin-de-Desmaures on the strength of an expected admission. If the I-129 route is chosen, the receipt date and any premium-processing option set the timeline, and the plant should not announce the posting internally until an approval notice exists.
A posting that changes from process engineering to shift management after approval is a change in the facts and should be reviewed again before the engineer continues, because the status was granted for the role described, not the role that evolved.