Been reading up on this company the last few days

Been reading up on this company the last few days and wow seems like a sure fire money maker! Question to all of you guys/gals here, has anyone ever been in aviation or an aviation facility for aircraft? Like an MRO or heavy check "C" and "D" and modification type company? Just wondering! The reason I ask, is do you know what these parts do or what they hold together and how often they need to be replaced? Seems to me if its a self lubricating bearing it would have a very long service life and not require replacement that often. Also other than china and their new airplane who else is building anything right now? Just my questions and thoughts before I do/do not buy in. Not a lot of info on the service life of these parts!