Trigger Programs: Improve performance, Reduce Application Code, after triggers replace end of day, month, and year processing resulting in data that is up to date in real time.
Improve performance: Because they run in the operating system storage pool.
Reduce Application Code: By attaching trigger programs to the file, the validation logic is consolidated into one place negating the need to do so in every application program that updates the file
Reduce Batch processing: After triggers are commonly used to replace End of Day, Month and Year processing which will keep your database up-to-date in real-time.