You can use the standard JobOps to accomplish this the way they have tested. You have the equipment database for tracking serial numbers in the standard. I never liked the other work ticket types for repair, so I would just use standard WT. I've demo'd this a lot, but none that have actually implemented it.
The advantage of Field Service is that you can structure the due dates and standard PM operations. It really has to do with volumes. If you have 100+ CNC machines and smaller pieces of equipment added to that, you need that tracking ability to stay on top of the scheduled maintenance.