Updating customer master using billing

Question

Hi ,
Let let me tell the business scenario
if you purchase something in supermarket, lifestyle etc
based on the amount u buy (say 2000,3000) they will give u points
say for 2000 - 5 points for 3000 - 10 points
so the first field is card type ie - master card, golden card, silver card etc
second field is card points - no. of points
see in business scenario, say after getting some points at one stage , customer can redeeme the points he got on the whole
ie he can get cash discount based on his points at certain stage
now my 50 points will be redeemed and next time i will have 0 points
now other fields are points redeemed, poiints in balance
now i got this screen working in customer master
data will be updated in ztable
now in billing , we have to write a user exit through which , we can update this points based on the amount of billing
ie updating customer master from billing user exit
can anyone tell what exit i have to use, what logic i have to write , and how to create project and all
Thanks,
Ratna

Answer 1

Hi,
User Exits are nothing but Customizing the SAP Standard prog. with out changing the exiting functionality.
Option, prepared by SAP to extend delivered standard-programs without modification of the original program at the customer. For potential customer requirements, which are not part of the standard, SAP installs blank containers, which can be filled with own functionalities by the customer. Customer-Exits are administered by SAP .
T-Codes are
SMOD - To find a Enahancement/User Exits
CMOD - To Create Enhancement/Project.
Follow the steps
1. Go to CMOD there you have to give the project name that project name should get from your Functional people, or if you know no problem.
2. Click on Create button it will asks save it local or Package.
3. In Enhancements it will give the All Exits Names then double click on your exit
4. It will take you into a Functional Module nothing but your Exit.
in that Exit you will find Include Program i.e. Eg: ZXQSMU01 where you are going to implement your logic.
5. Double Click on the Include program it will asks create object click enter
it will creates there you can write your logic save it local or any package and Activate it.
6. You need not to pass any values from Functional module/Exit to Include program that import/export values automatically program will access, you don't bother directly you can access the import/export etc. values in the program.
Finally your Exit and Project also Activate it. then check your requirement reached or not.
Following Exit try it.
1. V60F0001 - SD Billing plan (customer enhancement) diff. to billing
2. V60A0001 -  Customer functions in the billing document
3. V46H0001 - SD Customer functions for resource-related billing 
4. V05I0001  -  User exits for billing index   ETC...
     May be try these you can get or goto SMOD press F4 it will give a popup window there short text bill execute then you will get a list of exits check those.
if any clarifications reply me.
Regards
Ganesh