performance issue

Hi,

When I checked in ST22 I found that the below statement is causing TIME_OUT error.

LOOP AT t_data_ship.

CLEAR w_index.

w_index = sy-tabix.

CLEAR s_data_ship3.

s_data_ship3 = t_data_ship.

CLEAR w_wtyp.

w_wtyp = s_data_ship3-wtyp.

In the above statement time_out error is occuring at line CLEAR w_index.

w_index is declared like sy-tabix.

Is there any issue in clearing a variable inside the loop?

Please give me your suggestions