diff --git a/lib/update_database.py b/lib/update_database.py
index db4da19..753f23b 100644
--- a/lib/update_database.py
+++ b/lib/update_database.py
@@ -90,43 +90,29 @@ def get_sivas_teilestamm(sivas_ids, out_dir=os.environ.get('CREMIG_DATA'), overw
     """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')
+    if not os.path.isfile(sivas_teilestamm_exe):
+        raise FileNotFoundError(f"Check VPN connection or path of %SIVAS_DATABASE_QUERY% in cremig_setenv.bat")
+    
+    if not os.path.isdir(out_dir):
+        raise NotADirectoryError(f"Output directory for .csv-file(s) ${out_dir} doesn't exist.")
 
     if isinstance(sivas_ids, str):
         sivas_ids = list(set(sivas_ids.strip().split(",")))
-    
+
     ids_to_generate = []
     for id in sivas_ids:
-        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():
-            print(f"Partnumber '{id}' contains invalid characters. Please check given partnumber. Multiple partnumbers have to be specified as comma separated values without space, e.g. 200000089,200000090")
-            
+        out_file = os.path.join(out_dir, id + ".csv")
+        if not overwrite and os.path.isfile(out_file):
+            continue
+        ids_to_generate.append(f'"{id}"') # Anführungszeichen erforderlich, damit Art.Nr. mit Leerzeichen, z.B. "TOS Auswahl ILS" funktionieren
 
-    if os.path.isfile(sivas_teilestamm_exe):
-        
-        if os.path.isdir(out_dir):
+    if len(ids_to_generate) == 0:
+        print("CSV-file(s) already exist or given partnumber(s) are migrated.")
+        return
 
-            if len(ids_to_generate) == 0:
-                print("CSV-file(s) already exist or given partnumber(s) are migrated.")
-                return
-
-            else:
-                print(f"Attempting to generate csv-file(s) for given partnumber(s)...")
-
-                ids_to_generate = ",".join(ids_to_generate)
-                os.environ["SIVAS_EXCEL_EXPORT_DIR"] = out_dir
-                subprocess.run(f"{sivas_teilestamm_exe} -teilenr={ids_to_generate} -open_target_dir=n")
-        else:
-            print(f"Output directory for .csv-file(s) ${out_dir} doesn't exist.")
-    else:
-        print(f"Can't execute SIVAS-database query. Check VPN connection or check the path of %SIVAS_DATABASE_QUERY% in cremig_setenv.bat")
+    ids_to_generate = ",".join(ids_to_generate)
+    os.environ["SIVAS_EXCEL_EXPORT_DIR"] = out_dir
+    subprocess.run(f'{sivas_teilestamm_exe} -teilenr={ids_to_generate} -open_target_dir=n')
 
 
 if __name__ == '__main__':