changeover

noun

1. A conversion or transition from one thing to another.

   “The train runs slowly with frequent slacks for bridge and culvert repairs. At one point occurs the changeover from left- to right-hand running.”

   “Changeover from diesel to electric power can take place at any time while the locomotive is running and does not involve stopping the train.”

   “The changeover from dank, winding alleys to the openness, light and tranquility of the garden is utterly unexpected”

   “The hotel receptionist added that the message came late last night. Unfortunately it had got mislaid with the changeover from the night manager.”

   “The station is blessed with a cafe and staff accommodation, as it's an important crew changeover point, although this can be problematic when services are late.”