AMOS is a popular MRO System these days, particularly in UK & across Europe.
It was initially developed by Swissair as a dedicated MRO system, unlike other systems which are more generic. It as been constantly developed by Swiss (not always for the better)!
Good training for users is important to get the most out of it & large amounts of data must be entered accurately to make it work well (standard IT philosophy of garbage in, garbage out)!