Automating a maintenance schedule

Automating a maintenance schedule

Hello,
 
I have created a database with creator where I have the following forms:
  • Equipment
  • Maintenance Providers
  • Recommended Maintenance Schedule
  • Equipment Use History (for example, the hours we put on our tractor each month)
I have keyed the unique equipment through the entire database so that it is cross referenced.
 
I would like to automate the process of informing our maintenance providers when a piece of our equipment is in need of maintenance by the hours criteria in the "recommended maintenance schedule" are met in the hours column in "Equipment Use History".  I'm assuming I could create some kind of script upon load and validate of new data in "equipment use history" but am currently a bit lost.
 
I would appreciate your help.
 
Many thanks,
 
Jeff Branco