I'm translating a sentence from Russian that says that a chromatography room operator failed to inform the next shift worker that he needs to test a further three filters:
Cause of deviation: the operator failed to inform his сменщик that he had only managed to subject one filter out of four to integrity testing.
The word сменщик in Russian means "the next shift worker** (who continues the work of the previous shift worker). Multitran offers choices such as "shift replacement, reliever, relief, relief worker" etc.
What is the most natural term to use in English for this purpose?