diff --git a/README.md b/README.md
index 0a77c5e..0cf72ce 100644
--- a/README.md
+++ b/README.md
@@ -122,6 +122,7 @@ classDiagram
         class SiteGroupSQL{
         + site_group_uuid : UUID ≪ PK ≫
         + site_group_name : String(255) ≪ U ≫
+        + service_level : Integer ≪ U ≫
     }
 
     class SiteGroupSiteSQL{