diff --git a/MetricUpdater.cpp b/MetricUpdater.cpp
index 19f6623..ce090c9 100644
--- a/MetricUpdater.cpp
+++ b/MetricUpdater.cpp
@@ -41,17 +41,22 @@ namespace NebulOuS
 void MetricUpdater::AddMetricSubscription( const MetricTopic & TheMetrics,
                                            const Address OptimiserController )
 {
-    if( TheMetrics.is_object() )
-      for( const auto & [MetricName, TopicName] : TheMetrics.items() )
+    if( TheMetrics.is_object() && 
+        TheMetrics.at( NebulOuS::MetricList ).is_object() )
       {
-        auto [ MetricRecord, NewMetric ] = MetricValues.try_emplace( 
-                                           TopicName, MetricName, JSON() );
+        JSON MetricList = TheMetrics.at( NebulOuS::MetricList );
 
-        if( NewMetric )
-          Send( Theron::AMQ::NetworkLayer::TopicSubscription( 
-                Theron::AMQ::NetworkLayer::TopicSubscription::Action::Subscription,
-                TopicName ), 
-                Theron::AMQ::Network::GetAddress( Theron::Network::Layer::Session) );
+        for( const JSON MetricDefinition : MetricList.items() )      
+        {
+          auto [ MetricRecord, NewMetric ] = MetricValues.try_emplace( 
+                MetricDefinition.at( NebulOuS::MetricName ), JSON() );
+
+          if( NewMetric )
+            Send( Theron::AMQ::NetworkLayer::TopicSubscription( 
+                  Theron::AMQ::NetworkLayer::TopicSubscription::Action::Subscription,
+                  MetricRecord->first ), 
+                  Theron::AMQ::Network::GetAddress( Theron::Network::Layer::Session) );
+        }
       }
     else
     {
@@ -62,7 +67,7 @@ void MetricUpdater::AddMetricSubscription( const MetricTopic & TheMetrics,
                   << "in function " << Location.function_name() <<"] " 
                   << "The message to define a new metric subscription is given as "
                   << std::endl << TheMetrics.dump(2) << std::endl
-                  << "this is not a JSON object!";
+                  << "this is not as expected!";
 
       throw std::invalid_argument( ErrorMessage.str() );
     }
@@ -98,11 +103,12 @@ void MetricUpdater::UpdateMetricValue(
      const MetricValueUpdate & TheMetricValue, const Address TheMetricTopic)
 {
   Theron::AMQ::TopicName TheTopic 
-          = TheMetricTopic.AsString().erase(0, MetricValueRootString.size() );
+          = TheMetricTopic.AsString().erase( 0, 
+                                      NebulOuS::MetricValueRootString.size() );
         
   if( MetricValues.contains( TheTopic ) )
   {
-    MetricValues.at( TheTopic ).Value = TheMetricValue[ NebulOuS::ValueLabel ];
+    MetricValues.at( TheTopic ) = TheMetricValue[ NebulOuS::ValueLabel ];
     
     ValidityTime = std::max( ValidityTime, 
       TheMetricValue[ NebulOuS::TimePoint ].get< Solver::TimePointType >() );
@@ -135,10 +141,9 @@ void MetricUpdater::SLOViolationHandler(
 
   Solver::MetricValueType TheApplicationExecutionContext;
 
-  for( const auto & [_, MetricRecord ] : MetricValues )
-    if( !MetricRecord.Value.is_null() )
-      TheApplicationExecutionContext.emplace( MetricRecord.OptimisationName,
-                                              MetricRecord.Value );
+  for( const auto & [ MetricName, MetricValue ] : MetricValues )
+    if( !MetricValue.is_null() )
+      TheApplicationExecutionContext.emplace( MetricName, MetricValue );
 
   // The application context can then be sent to the solution manager 
   // using the corresponding message, and the time stamp of the severity 
diff --git a/MetricUpdater.hpp b/MetricUpdater.hpp
index d4fcf1c..db2b7ca 100644
--- a/MetricUpdater.hpp
+++ b/MetricUpdater.hpp
@@ -88,7 +88,15 @@ constexpr std::string_view TimePoint  = "predictionTime";
 // defined next.
 
 constexpr std::string_view MetricSubscriptions 
-          = "eu.nebulouscloud.optimiser.solver.metrics";
+          = "eu.nebulouscloud.monitoring.metric_lists";
+
+// The JSON message attribute for the list of metrics is another JSON object
+// stored under the following key, see the Event type III defined in 
+// https://158.39.75.54/projects/nebulous-collaboration-hub/wiki/slo-severity-based-violation-detector
+// where the name of the metric is defined under as sub-key.
+
+constexpr std::string_view MetricList = "metric_list";
+constexpr std::string_view MetricName = "name";
 
 // The metric value messages will be published on different topics and to 
 // check if an inbound message is from a metric value topic, it is necessary 
@@ -154,33 +162,11 @@ private:
   // --------------------------------------------------------------------------
   //
   // The metric values are stored essentially as a JSON values where the 
-  // attributes are the metric names and the values are JSON values because 
-  // they are polymorphic with respect to different variable types, and as 
-  // they arrive as JSON values this avoids converting the values on input and
-  // output. The metric optimisation name is just a string.
+  // attributes are the metric names and the values are JSON values. It is 
+  // assumed that same metric name is used both for the optimisation model 
+  // and for the metric topic.
 
-  class MetricValueRecord
-  {
-  public:
-    const std::string OptimisationName;
-    JSON              Value;
-
-    MetricValueRecord( const std::string & TheName, const JSON InitialValue )
-    : OptimisationName( TheName ), Value( InitialValue )
-    {}
-
-    MetricValueRecord( const MetricValueRecord & Other )
-    : OptimisationName( Other.OptimisationName ), Value( Other.Value )
-    {}
-
-    MetricValueRecord()  = delete;
-    ~MetricValueRecord() = default;
-  };
-
-  // This value record is used in the map where the subscribed topic name is 
-  // the key so that values can quickly be updated when messages arrives.
-
-  std::unordered_map< Theron::AMQ::TopicName, MetricValueRecord > MetricValues;
+  std::unordered_map< Theron::AMQ::TopicName, JSON > MetricValues;
 
   // The metric values should ideally be forecasted for the same future time
   // point, but this may not be assured, and as such a zero-order hold is