IMHO

Menurut referensi berikut:
line = production line = jalur produksi
changeover = pergantian jalur produksi
Ref.:
line = production line, mechanical system in a factory whereby an article is conveyed through sites at which successive operations are performed on it.

*Changeover* in manufacturing is the process of *converting a line or machine* from running one product to another. Example: A soft drink bottler may *run 16oz glass bottles* one day, perform a *changeover* on the line and then *run 20oz plastic bottles* the next day.


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Note added at 7 hrs (2008-08-14 00:43:58 GMT)
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switchover = pemindahan sistem, misalnya pemindahan dari sistem pemanas ke sistem pendingin, pemindahan dari dari sistem utama ke sistem cadangan (bila sistem utama mengalami gangguan), dll.
Ref.:
Switchover is an action that occurs when a *redundant device* replaces a *primary device* that *failed*.
www.cxr.com/aj/glossary.html

Switchover is the capability to manually switch over *from one system to a redundant or standby computer server*, system, or network upon the *failure* or *abnormal termination* of the previously active server, system, or network.
http://en.wikipedia.org/wiki/Switchover

Berdasarkan semua rujukan di atas, maka terlihat jelas persamaan dan perbedaan antara changeover dan switchover:
Persamaan: keduanya sama2 merujuk pada pergantian/pemindahan.
Perbedaan: changeover dilakukan secara sengaja dan terencana, bukan karena adanya gangguan sistem.
Sebaliknya, switchover dilakukan secara terpaksa karena adanya gangguan sistem atau matinya sistem.