I really wish more people using FLEXlm would at least sit down and talk with their IT department and act like a "team". You know: Act like they work for the same damn company. One of the most common mistakes I've seen is when the CAD group and the IT department develop an animosity towards each other, and any hope of cooperative planning and execution is pretty much destroyed. It puts the company in the position of setting the baby in the street waiting for a truck to come along and run it over.
When you involve your IT department, you gain the advantages of expanded resources, greater oversight, and better fault tolerance. I mean REAL fault tolerance. One example is backups, especially backing up the FLEXlm license files, but also option files, service configurations, and so on. More than that, you gain the advantages of putting the entire server into a virtual environment (Hyper-V or vSphere, for example). One of the most common risk scenarios I've seen is running all your licenses on ONE physical server. Even two physical servers is not a good idea. Sure, it works. But when it fails, it means a lot of unnecessary work ahead of you.
When servers are virtualized properly (e.g. distributed, SANs, failover, etc.) you make your license availabilty resilient. That word has been overused and burned out by marketing pukes after a few too many Martinis and golf course sunburns, but the word has a real meaning to IT architects and engineers. It means that your systems can bounce back from potential failure. When all licenses are on one physical server, not only are you facing the task of rebuilding a failed box, but reinstalling the licenses and dealing with hardware changes (i.e. a failed NIC or hard drive). In the virtual world those things remain portable and tied to the virtual guest. But WAAAAAAAAY more important than that is the ability to use VMotion or Live Migration, which automatically, and seamlessly moves a virtual guest to a different physical host node when problems occur.
Most small engineering shops don't often bother with network licensing, so it's usually medium to large shops that have a real "IT department". If you have "servers", hopefully some are "virtual" (if none of your servers are virtual, it may be time to have a discussion with your IT staff), and if you have virtual servers, you should be considering that approach for your FLEXlm servers.