diff --git a/lib/liudesk_cmdb/model.rb b/lib/liudesk_cmdb/model.rb
index 95c18154f1bb11add7de7e5e53c955e3abe7e45b..b97fc9fb67a3065c7c955777968e172f835dced7 100644
--- a/lib/liudesk_cmdb/model.rb
+++ b/lib/liudesk_cmdb/model.rb
@@ -17,6 +17,7 @@ module LiudeskCMDB
       end
       @old_data = @data.deep_clone
       @unknown = nil
+      @retrieved = nil
     end
 
     def logger
@@ -39,6 +40,14 @@ module LiudeskCMDB
       !identifier.nil?
     end
 
+    def retrieved?
+      !@retrieved.nil?
+    end
+
+    def retrieved_at
+      @retrieved || Time.new(0)
+    end
+
     def renamed?
       old_identifier != identifier
     end
@@ -293,6 +302,7 @@ module LiudeskCMDB
         end
       end
 
+      @retrieved = Time.now
       self
     end
   end