Minor changing of plant layout: This is caused from minor improvements of operation such as improvement of standard operation procedure, new inspection method etc.
Rearrangement of plant layout: This is caused from development of new product. Thus, the necessary facilities should be arranged in order to support production efficiently.
Rearrangement of facility: This is bigger than the previous item because in term of facility is more general than layout. It includes all supports rather than focused production such as parking area, toilet, facilities and so on.
Building new plant: This is the biggest one since all of the previous items must be taken into consideration including with the right location.