User Exit In computer software, a user exit is a place in a software program where a customer can arrange for their own tailor-made program to be called. In the R/3 system from SAP, a user exit is contrasted with a customer exit and allows a customer's developer to access program components and data objects within the R/3 system. In R/3, some user exits use
Debugging a User Exit or Program
1) Execute tcode SMOD to find available enhancement/modifications.
2) Create a project for the enhancement in tcode CMOD.
3) You must activate your project first in order to hit a break-point or get into debug mode for your existing enhancements/modifications, if you do not, the best you will be able to do is step through the main program until you hit the call for that particular customer enhancement.
4) To get into debug, you can enter a hard break-point in the enhancement itself, set a soft break-point with the stop sign, or the long way, before you execute your transaction or while you are in your transaction, you can place a /h in the ok code area (this is the area of your gui where you can type in a tcode). Once you have the /h, hit enter and that will take you into debug, from there, you can do many different things to find exactly what you are looking for.
1) Identify the main program you want to locate a user exit/debug.
2) For example, go to SE80 and do a search by program or dev class (SAPMV45A sales order or Dev Class VMOD, most SD user exits are in this dev class). In SE80 if you go by program, most user exit programs end in a 'Z' on a rare occasion 'X' or 'Y'.
3) If you are looking at including MV45AFZZ, you can see where there are different forms. These forms will get called at times within the program. If you are looking to fill the storage location on the sales order, you will probably want to take a look at the perform that fills in a field in vbap.
4) If this is what you are trying to accomplish, you will need to do the select against the config Table TVKOL based on the shipping point/plant and possibly storage condition based on your picking strategies.
5) For the debug part, you can do the same as in the enhancements/modifications but you will not need to activate any projects.