Trigger , report program

Hi,

I am working on an interface which sends out Material Master data of materials of a particular plant.

The requirement consists of extracting data from many tables (like MARA MSEG KEPH) and after some calculations output the final data into a flat file, there on the middleware will take care of the rest.

The program has to be triggered as when there is a change in material master data of materials from that particular plant only.

I created the program to generate the flat file. But I dont know how to create a trigger such that whenever there are changes in the master data of the materials of this specific plant, this program will create the flat file on the application server.

Please provide me an approach to solve this problem.

Thanks

pratyusha