If you want to know how much the run time of your program by insert ABAP statement, you can insert command "GET RUN TIME" in the top and bottom of program block and minus two times.

Example

DATA: time1 TYPE I,
      time2 TYPE I,
      runtime TYPE I.
GET RUN TIME FIELD time1.
          .....
  ...program statement...
          .....
GET RUN TIME FIELD time2.
runtime = time2 - time1.