The frequency of checking the instrument performance may depend on the industry you are in. What we do at our site (in the Pharma industry) is: annually perform a complete performance verification of the instrument. If any maintenance/repairs are performed during the year, we retest the parts of the system affected. On a daily/before use basis, we perform a flow rate check and run a system suitability.
Have you looked at the perfromance metrics, number of injections, volume pumped etc. That number will lead to an understanding of the usage rate. based upon when it was installed.
The UPLC is designed to handle many times the amount of injections as an HPLC, understanding that the cycle time is much lower and runs faster. However, at some point everything does wear out, but if you are just starting out the usage rate could be low and thus maintenance would be low. You could look at the time spent at pressure too. The pump will tell you how many liters at what backpressure and this too is useful data. Basically, the amount you use the isntrument will determine when to service. The usage can start to increase as the unit get used more frquently, but the standard maintennace design period was for 12 months.
Let me know if you need help on where to find the data in the Console.