[Alternative] according to specialism; e.g. Chemist ; Human Factors Specialist [Role] someone with relevant technical knowledge, e.g. knowledge about effect of varying reaction conditions; training in human reliability analysis, and human error identification [Name] 
Specialist
S t u d y l e a d e r
R e c o r d e r
D e s i g n e r
U s e r
S p e c i a l i s t
M a i n t a i n e r