Does anyone implemented eAM AND Field Service?

My customer has already eAM for preventive maintenance (  Installed Base etc..); they need a call centre for reactive maintenance, and FS is great for the front office part and as well with the scheduling / dispatch centre (technicians need to cover all country by location etc..) . My point is I need to use only 1 application for technicians they do both preventive and reactive jobs), scheduling and mobile in same place. Service Request could be dealt with in eAM but then I would lose the FS dispatch centre function ….  Bring SR in eAM and interface WO with