Many scenarios / use-case implies that you will count more users than devices that access to your database.
For instance, it will be true for part-time users and 24/24 office; In particular for the first case, counting each Individual instead of Human Resource lead to unfair prices.
You want to install 10 computers with FMPA accessing to your FM Server. But 5 workstation are used by 10 50% part-time workers.
You are supposed to buy 15 FUL (full) licences. But you only installed 10 FMPA, 1 FMS and nothing more.
My idea is simply to amend FUL as follow :
FileMaker allow the licensed company to count Devices instead of Users, as long as the number of devices where a FileMaker apps is running are LESS than the individual people that uses the FM Application.