diff --git a/lib/update_database.py b/lib/update_database.py
index 02619d9..33b1e93 100644
--- a/lib/update_database.py
+++ b/lib/update_database.py
@@ -82,7 +82,7 @@ def get_sivas_dbase(sivas_id, out_dir):
         print(f"Can't execute SIVAS-database query. Check VPN connection and check the path of %SIVAS_DATABASE_QUERY% in cremig_setenv.bat")
         return False
 
-def get_sivas_teilestamm(sivas_ids, out_dir):
+def get_sivas_teilestamm(sivas_ids, out_dir, overwrite=True):
     """call the sivas exe for getting all csv files with the item data for the given sivas ids"""
 
     sivas_teilestamm_exe = os.environ.get('SIVAS_TEILESTAMM')
@@ -92,9 +92,13 @@ def get_sivas_teilestamm(sivas_ids, out_dir):
     
     ids_to_generate = []
     for id in sivas_ids:
-        id = id.replace(" ", "")
-        out_file = os.path.join(out_dir, id + ".csv")
-        if not os.path.isfile(out_file):
+        id = id.replace(" ", "") 
+        if not overwrite:
+            out_file = os.path.join(out_dir, id + ".csv")
+            if not os.path.isfile(out_file):
+                ids_to_generate.append(id)
+                continue
+        else:
             ids_to_generate.append(id)
         
         if not id.isnumeric():
@@ -127,6 +131,7 @@ if __name__ == '__main__':
     parser.add_argument('-r', '--rd', action='store_true', help='fetch list of existing parts from network drive')
     parser.add_argument('-b', '--blacklist', action='store_true', help='fetch list of not allowed parts from network drive')
     parser.add_argument('-t', '--teilestamm', action='store_true', help='fetch teilestamm-data for given partnumbers as csv')
+    parser.add_argument('-w', '--overwrite', action='store_true', help='vorhandene CSV-Dateien werden nicht erneut aus SIVAS abgefragt')
 
     args = parser.parse_args()
 
@@ -138,8 +143,13 @@ if __name__ == '__main__':
     elif args.sivasid:
 
         if args.teilestamm:
-            get_sivas_teilestamm(args.sivasid, out_dir)
         
+            overwrite = args.overwrite
+            if overwrite:
+                get_sivas_teilestamm(args.sivasid, out_dir, overwrite = True)
+            else:
+                get_sivas_teilestamm(args.sivasid, out_dir, overwrite = False)
+
         else:
             get_sivas_dbase(args.sivasid, out_dir)