Your own operator's manual is a very simplified and easy to use for your periodic maintenance on the machine. This is a very simple to use and maintain machine.
The most important aspects would be:
a) Turbo Blower Oil Replaced every 1000 Hours
b) Vacuum Pump Oil Replaced every 1500 Hours
c) Vacuum Pump Oil Filter Replaced every 3000 Hours
d) Clean and Lubricate the machine once a month
e) Double check Z-Axis Mirror for damages
f) Clean the focusing lens once every shift
g) Replace Chiller Water once a year (Don't forget to add Isoguard)
As far as optics (internal/external) this will vary depending on laser power, and materials processed. Usually, machines with 2000 Watt resonators will last long, long hours if properly cared for. Make sure you get the highest purity possible in your lasergas mix. This will eliminate contamination of your internals.
Your dust collector must work at all times, if it doesn't, all the smoke and dust particles will end up sticking to your Y-Axis ballscrew and with time it will wear. And also clean-up and lubricate the X-Axis rollers as these will stick with time if not properly cared for.
You may want to contact your service department at Amada just to double check but like I said earlier, this is a very simple machine to maintain.
Good Luck