In the first article here regarding capturing building services data on existing buildings, the focus was mainly on discrete components that sit in a system, with for instance lights, there may be an issue regarding which circuit they are linked to which switch or circuit fused in a sub-board, and this could easily be added
For new assets, if BIM models are used for design/construction then the modeled services are available for use in FM stage of the project. If there are existing assets that are partially through their lifecycle and services data is required for them, then you will need to consider the level of information that you require
Revit to 3D PDF’s & Export to Excel For designers and contractors, working on the same documentation process, having expensive or specialized software for communication is part of the process. But in the FM/AM world, a lot of people who will be using the information will not want to download specialist viewers to review information.