diff --git a/app/models/grader_configuration.rb b/app/models/grader_configuration.rb
--- a/app/models/grader_configuration.rb
+++ b/app/models/grader_configuration.rb
@@ -12,6 +12,7 @@
   MULTIPLE_IP_LOGIN_KEY = 'right.multiple_ip_login'
   VIEW_TESTCASE = 'right.view_testcase'
   SINGLE_USER_KEY = 'system.single_user_mode'
+  SYSTEM_USE_PROBLEM_GROUP = 'system.use_problem_group'
 
   cattr_accessor :config_cache
   cattr_accessor :task_grading_info_cache
@@ -119,6 +120,10 @@
   def self.analysis_mode?
     return get(SYSTEM_MODE_CONF_KEY) == 'analysis'
   end
+
+  def self.use_problem_group?
+    return get(SYSTEM_USE_PROBLEM_GROUP)
+  end
   
   def self.contest_time_limit
     contest_time_str = GraderConfiguration[CONTEST_TIME_LIMIT_KEY]