First test your code with '/h' type in command window which shall take you to
debug or by putting break points with F8. You test your program from code and
then go to se30 performance analysis transaction and there you can know what are
the drawbacks. Then go to SLIN transaction and do extended syntax check or from
code in menu options where you have debugging -> extended check and the program
id ready without error.
Testing your code.
As mentioned above after doing syntax check and extended syntax check you
have to create a TEST PLAN. You have to test all possible Postive & Negative
Test for division by zero if it involves calculation or code accordingly.
Try to test for field overflows. If it involves sap script or smart forms
try to print outputs which have single page and also multiple page and which
does not have any output at all.
Test by leaving all parameters in selection screen blank.
Test by entering wrong values in selection screen and display a pop-up if
the user enters wrong selection screen values.
You can also do ABAP trace and SQL trace to make sure that your program is
As mentioned above type /h in command line and try to execute the program.
Another way is to set break-point at the function module or the required line
and do single step execute or execute. Once you finished debugging, you can
select Delete to clear all the break points.
Third option in certain cases is to check for sy-subrc <> 0 and proceed
from there by making it 0 by updating the sy-subrc in the debug editor and
see how the program behaves if the value is what you enterd in the debug
screen. For certain case try to use WATCH POINT feature in debug editor.