diff --git a/ApplicationCode/Application/Tools/RiaSummaryTools.cpp b/ApplicationCode/Application/Tools/RiaSummaryTools.cpp
index c5ef426e7a..0d528c82c3 100644
--- a/ApplicationCode/Application/Tools/RiaSummaryTools.cpp
+++ b/ApplicationCode/Application/Tools/RiaSummaryTools.cpp
@@ -58,8 +58,7 @@ RimSummaryCaseMainCollection* RiaSummaryTools::summaryCaseMainCollection()
 //--------------------------------------------------------------------------------------------------
 /// Update the summary curves referencing this curve, as the curve is identified by the name
 //--------------------------------------------------------------------------------------------------
-void RiaSummaryTools::notifyCalculatedCurveNameHasChanged( const QString& previousCurveName,
-                                                           const QString& currentCurveName )
+void RiaSummaryTools::notifyCalculatedCurveNameHasChanged( int calculationId, const QString& currentCurveName )
 {
     RimSummaryPlotCollection* summaryPlotColl = RiaSummaryTools::summaryPlotCollection();
 
@@ -68,14 +67,11 @@ void RiaSummaryTools::notifyCalculatedCurveNameHasChanged( const QString& previo
         for ( RimSummaryCurve* curve : plot->summaryCurves() )
         {
             RifEclipseSummaryAddress adr = curve->summaryAddressY();
-            if ( adr.category() == RifEclipseSummaryAddress::SUMMARY_CALCULATED )
+            if ( adr.category() == RifEclipseSummaryAddress::SUMMARY_CALCULATED && adr.id() == calculationId )
             {
-                if ( adr.quantityName() == previousCurveName.toStdString() )
-                {
-                    RifEclipseSummaryAddress updatedAdr = RifEclipseSummaryAddress::calculatedAddress(
-                        currentCurveName.toStdString() );
-                    curve->setSummaryAddressYAndApplyInterpolation( updatedAdr );
-                }
+                RifEclipseSummaryAddress updatedAdr =
+                    RifEclipseSummaryAddress::calculatedAddress( currentCurveName.toStdString(), calculationId );
+                curve->setSummaryAddressYAndApplyInterpolation( updatedAdr );
             }
         }
     }
diff --git a/ApplicationCode/Application/Tools/RiaSummaryTools.h b/ApplicationCode/Application/Tools/RiaSummaryTools.h
index 047e54f340..3b5cdfd923 100644
--- a/ApplicationCode/Application/Tools/RiaSummaryTools.h
+++ b/ApplicationCode/Application/Tools/RiaSummaryTools.h
@@ -39,7 +39,8 @@ class RiaSummaryTools
 public:
     static RimSummaryPlotCollection*     summaryPlotCollection();
     static RimSummaryCaseMainCollection* summaryCaseMainCollection();
-    static void notifyCalculatedCurveNameHasChanged( const QString& previousCurveName, const QString& currentCurveName );
+
+    static void notifyCalculatedCurveNameHasChanged( int calculationId, const QString& currentCurveName );
 
     static RimSummaryPlot*           parentSummaryPlot( caf::PdmObject* object );
     static RimSummaryPlotCollection* parentSummaryPlotCollection( caf::PdmObject* object );
diff --git a/ApplicationCode/Commands/FlowCommands/RicPlotProductionRateFeature.cpp b/ApplicationCode/Commands/FlowCommands/RicPlotProductionRateFeature.cpp
index f396511b06..2c1fae6022 100644
--- a/ApplicationCode/Commands/FlowCommands/RicPlotProductionRateFeature.cpp
+++ b/ApplicationCode/Commands/FlowCommands/RicPlotProductionRateFeature.cpp
@@ -322,7 +322,8 @@ RimSummaryCurve* RicPlotProductionRateFeature::addSummaryCurve( RimSummaryPlot*
                                    -1,
                                    -1,
                                    -1,
-                                   false );
+                                   false,
+                                   -1 );
 
     if ( !gridSummaryCase->summaryReader()->hasAddress( addr ) )
     {
diff --git a/ApplicationCode/Commands/RicReplaceSummaryCaseFeature.cpp b/ApplicationCode/Commands/RicReplaceSummaryCaseFeature.cpp
index cc7abf8ab3..2b34a9c187 100644
--- a/ApplicationCode/Commands/RicReplaceSummaryCaseFeature.cpp
+++ b/ApplicationCode/Commands/RicReplaceSummaryCaseFeature.cpp
@@ -18,15 +18,23 @@
 
 #include "RicReplaceSummaryCaseFeature.h"
 
+#include "RiaApplication.h"
 #include "RiaLogging.h"
 #include "RiaSummaryTools.h"
 
 #include "RicImportGeneralDataFeature.h"
 
+#include "RimCalculatedSummaryCase.h"
 #include "RimFileSummaryCase.h"
+#include "RimProject.h"
+#include "RimSummaryAddress.h"
+#include "RimSummaryCalculation.h"
+#include "RimSummaryCalculationCollection.h"
+#include "RimSummaryCalculationVariable.h"
 #include "RimSummaryCase.h"
 #include "RimSummaryCaseCollection.h"
 #include "RimSummaryCaseMainCollection.h"
+#include "RimSummaryCurve.h"
 #include "RimSummaryPlot.h"
 #include "RimSummaryPlotCollection.h"
 
@@ -65,9 +73,44 @@ void RicReplaceSummaryCaseFeature::onActionTriggered( bool isChecked )
     summaryCase->createRftReaderInterface();
     RiaLogging::info( QString( "Replaced summary data for %1" ).arg( oldSummaryHeaderFilename ) );
 
+    RimSummaryCalculationCollection* calcColl = RiaApplication::instance()->project()->calculationCollection();
+
+    // Find and update all changed calculations
+    std::set<int> ids;
+    for ( RimSummaryCalculation* summaryCalculation : calcColl->calculations() )
+    {
+        bool needsUpdate = checkIfCalculationNeedsUpdate( summaryCalculation, summaryCase );
+        if ( needsUpdate )
+        {
+            ids.insert( summaryCalculation->id() );
+            summaryCalculation->parseExpression();
+            summaryCalculation->calculate();
+            summaryCalculation->updateDependentCurvesAndPlots();
+        }
+    }
+
     RimSummaryPlotCollection* summaryPlotColl = RiaSummaryTools::summaryPlotCollection();
     for ( RimSummaryPlot* summaryPlot : summaryPlotColl->summaryPlots )
     {
+        // Update summary curves on calculated data
+        std::vector<RimSummaryCurve*> summaryCurves = summaryPlot->summaryCurves();
+        for ( RimSummaryCurve* summaryCurve : summaryCurves )
+        {
+            RifEclipseSummaryAddress summaryAddressY = summaryCurve->summaryAddressY();
+            if ( summaryAddressY.category() == RifEclipseSummaryAddress::SUMMARY_CALCULATED &&
+                 ids.find( summaryAddressY.id() ) != ids.end() )
+            {
+                RifCalculatedSummaryCurveReader reader( calcColl );
+                RimSummaryCalculation*          calculation = reader.findCalculationByName( summaryAddressY );
+                QString                         description = calculation->description();
+
+                RifEclipseSummaryAddress updatedAdr =
+                    RifEclipseSummaryAddress::calculatedAddress( description.toStdString(), calculation->id() );
+                summaryCurve->setSummaryAddressYAndApplyInterpolation( updatedAdr );
+                summaryCurve->loadDataAndUpdate( true );
+            }
+        }
+
         summaryPlot->loadDataAndUpdate();
     }
 }
@@ -80,3 +123,21 @@ void RicReplaceSummaryCaseFeature::setupActionLook( QAction* actionToSetup )
     actionToSetup->setText( "Replace" );
     actionToSetup->setIcon( QIcon( ":/ReplaceCase16x16.png" ) );
 }
+
+//--------------------------------------------------------------------------------------------------
+///
+//--------------------------------------------------------------------------------------------------
+bool RicReplaceSummaryCaseFeature::checkIfCalculationNeedsUpdate( const RimSummaryCalculation* summaryCalculation,
+                                                                  const RimFileSummaryCase*    summaryCase )
+{
+    std::vector<RimSummaryCalculationVariable*> variables = summaryCalculation->allVariables();
+    for ( RimSummaryCalculationVariable* variable : variables )
+    {
+        if ( variable->summaryCase() == summaryCase )
+        {
+            return true;
+        }
+    }
+
+    return false;
+}
diff --git a/ApplicationCode/Commands/RicReplaceSummaryCaseFeature.h b/ApplicationCode/Commands/RicReplaceSummaryCaseFeature.h
index 767588a430..0d60497cb1 100644
--- a/ApplicationCode/Commands/RicReplaceSummaryCaseFeature.h
+++ b/ApplicationCode/Commands/RicReplaceSummaryCaseFeature.h
@@ -20,6 +20,9 @@
 
 #include "cafCmdFeature.h"
 
+class RimSummaryCalculation;
+class RimFileSummaryCase;
+
 class RicReplaceSummaryCaseFeature : public caf::CmdFeature
 {
     CAF_CMD_HEADER_INIT;
@@ -28,4 +31,7 @@ protected:
     bool isCommandEnabled() override;
     void onActionTriggered( bool isChecked ) override;
     void setupActionLook( QAction* actionToSetup ) override;
+
+    bool checkIfCalculationNeedsUpdate( const RimSummaryCalculation* summaryCalculation,
+                                        const RimFileSummaryCase*    summaryCase );
 };
diff --git a/ApplicationCode/Commands/SummaryPlotCommands/RicSummaryCurveCalculator.cpp b/ApplicationCode/Commands/SummaryPlotCommands/RicSummaryCurveCalculator.cpp
index c17062a0eb..98e3640088 100644
--- a/ApplicationCode/Commands/SummaryPlotCommands/RicSummaryCurveCalculator.cpp
+++ b/ApplicationCode/Commands/SummaryPlotCommands/RicSummaryCurveCalculator.cpp
@@ -101,7 +101,7 @@ bool RicSummaryCurveCalculator::parseExpression() const
         QString currentCurveName = m_currentCalculation->description();
         if ( previousCurveName != currentCurveName )
         {
-            RiaSummaryTools::notifyCalculatedCurveNameHasChanged( previousCurveName, currentCurveName );
+            RiaSummaryTools::notifyCalculatedCurveNameHasChanged( m_currentCalculation()->id(), currentCurveName );
         }
 
         m_currentCalculation()->updateDependentCurvesAndPlots();
@@ -122,7 +122,8 @@ void RicSummaryCurveCalculator::fieldChangedByUi( const caf::PdmFieldHandle* cha
         m_newCalculation = false;
 
         RimSummaryCalculation* rimCalc = calculationCollection()->addCalculation();
-        m_currentCalculation           = rimCalc;
+        RiaApplication::instance()->project()->assignCalculationIdToCalculation( rimCalc );
+        m_currentCalculation = rimCalc;
 
         this->updateConnectedEditors();
     }
@@ -246,7 +247,7 @@ bool RicSummaryCurveCalculator::calculate() const
         QString currentCurveName = m_currentCalculation->description();
         if ( previousCurveName != currentCurveName )
         {
-            RiaSummaryTools::notifyCalculatedCurveNameHasChanged( previousCurveName, currentCurveName );
+            RiaSummaryTools::notifyCalculatedCurveNameHasChanged( m_currentCalculation()->id(), currentCurveName );
         }
 
         if ( !m_currentCalculation()->calculate() )
diff --git a/ApplicationCode/FileInterface/RifEclipseSummaryAddress.cpp b/ApplicationCode/FileInterface/RifEclipseSummaryAddress.cpp
index 7db8a19a51..b3bf81b632 100644
--- a/ApplicationCode/FileInterface/RifEclipseSummaryAddress.cpp
+++ b/ApplicationCode/FileInterface/RifEclipseSummaryAddress.cpp
@@ -41,6 +41,7 @@ RifEclipseSummaryAddress::RifEclipseSummaryAddress( SummaryVarCategory
     , m_cellK( -1 )
     , m_aquiferNumber( -1 )
     , m_isErrorResult( false )
+    , m_id( -1 )
 {
     std::tuple<int32_t, int32_t, int32_t> ijkTuple;
     std::pair<int16_t, int16_t>           reg2regPair;
@@ -98,6 +99,9 @@ RifEclipseSummaryAddress::RifEclipseSummaryAddress( SummaryVarCategory
         case SUMMARY_AQUIFER:
             m_aquiferNumber = RiaStdStringTools::toInt( identifiers[INPUT_AQUIFER_NUMBER] );
             break;
+        case SUMMARY_CALCULATED:
+            m_id = RiaStdStringTools::toInt( identifiers[INPUT_ID] );
+            break;
     }
 
     // Set quantity for all categories
@@ -252,7 +256,7 @@ RifEclipseSummaryAddress RifEclipseSummaryAddress::fromEclipseTextAddress( const
             break;
 
         case SUMMARY_CALCULATED:
-            address = calculatedAddress( quantityName );
+            address = calculatedAddress( quantityName, RiaStdStringTools::toInt( names[0].toStdString() ) );
             break;
 
         case SUMMARY_IMPORTED:
@@ -503,11 +507,12 @@ RifEclipseSummaryAddress RifEclipseSummaryAddress::blockLgrAddress( const std::s
 //--------------------------------------------------------------------------------------------------
 ///
 //--------------------------------------------------------------------------------------------------
-RifEclipseSummaryAddress RifEclipseSummaryAddress::calculatedAddress( const std::string& quantityName )
+RifEclipseSummaryAddress RifEclipseSummaryAddress::calculatedAddress( const std::string& quantityName, int id )
 {
     RifEclipseSummaryAddress addr;
     addr.m_variableCategory = SUMMARY_CALCULATED;
     addr.m_quantityName     = quantityName;
+    addr.m_id               = id;
     return addr;
 }
 
@@ -646,6 +651,11 @@ std::string RifEclipseSummaryAddress::uiText() const
             text += ":" + std::to_string( this->aquiferNumber() );
         }
         break;
+        case SUMMARY_CALCULATED:
+        {
+            text += ":" + std::to_string( this->id() );
+        }
+        break;
     }
 
     return text;
@@ -676,6 +686,8 @@ std::string RifEclipseSummaryAddress::uiText( RifEclipseSummaryAddress::SummaryI
             return std::to_string( aquiferNumber() );
         case INPUT_VECTOR_NAME:
             return quantityName();
+        case INPUT_ID:
+            return std::to_string( id() );
     }
     return "";
 }
@@ -967,6 +979,11 @@ bool operator==( const RifEclipseSummaryAddress& first, const RifEclipseSummaryA
             if ( first.aquiferNumber() != second.aquiferNumber() ) return false;
         }
         break;
+        case RifEclipseSummaryAddress::SUMMARY_CALCULATED:
+        {
+            if ( first.id() != second.id() ) return false;
+        }
+        break;
     }
     if ( first.isErrorResult() != second.isErrorResult() ) return false;
     return true;
diff --git a/ApplicationCode/FileInterface/RifEclipseSummaryAddress.h b/ApplicationCode/FileInterface/RifEclipseSummaryAddress.h
index cd40fbc4f5..ef422a25f0 100644
--- a/ApplicationCode/FileInterface/RifEclipseSummaryAddress.h
+++ b/ApplicationCode/FileInterface/RifEclipseSummaryAddress.h
@@ -71,6 +71,7 @@ public:
         INPUT_SEGMENT_NUMBER,
         INPUT_AQUIFER_NUMBER,
         INPUT_VECTOR_NAME,
+        INPUT_ID
     };
 
 public:
@@ -84,6 +85,7 @@ public:
         , m_cellK( -1 )
         , m_aquiferNumber( -1 )
         , m_isErrorResult( false )
+        , m_id( -1 )
     {
     }
 
@@ -99,7 +101,8 @@ public:
                               int32_t            cellJ,
                               int32_t            cellK,
                               int16_t            aquiferNumber,
-                              bool               isErrorResult )
+                              bool               isErrorResult,
+                              int32_t            id )
         : m_variableCategory( category )
         , m_quantityName( quantityName )
         , m_regionNumber( regionNumber )
@@ -113,6 +116,7 @@ public:
         , m_cellK( cellK )
         , m_aquiferNumber( aquiferNumber )
         , m_isErrorResult( isErrorResult )
+        , m_id( id )
     {
     }
 
@@ -147,7 +151,7 @@ public:
     static RifEclipseSummaryAddress blockAddress( const std::string& quantityName, int i, int j, int k );
     static RifEclipseSummaryAddress
                                     blockLgrAddress( const std::string& quantityName, const std::string& lgrName, int i, int j, int k );
-    static RifEclipseSummaryAddress calculatedAddress( const std::string& quantityName );
+    static RifEclipseSummaryAddress calculatedAddress( const std::string& quantityName, int id );
     static RifEclipseSummaryAddress importedAddress( const std::string& quantityName );
     static RifEclipseSummaryAddress ensembleStatisticsAddress( const std::string& quantityName,
                                                                const std::string& dataQuantityName );
@@ -207,6 +211,10 @@ public:
     {
         return m_aquiferNumber;
     }
+    int id() const
+    {
+        return m_id;
+    }
     std::string blockAsString() const;
 
     const std::string ensembleStatisticsQuantityName() const;
@@ -252,6 +260,12 @@ public:
     {
         return m_isErrorResult;
     }
+
+    void setId( int id )
+    {
+        m_id = id;
+    }
+
     bool hasAccumulatedData() const;
 
 private:
@@ -274,6 +288,7 @@ private:
     int16_t            m_aquiferNumber;
     SummaryVarCategory m_variableCategory;
     bool               m_isErrorResult;
+    int32_t            m_id;
 };
 
 bool operator==( const RifEclipseSummaryAddress& first, const RifEclipseSummaryAddress& second );
diff --git a/ApplicationCode/FileInterface/RifEclipseUserDataKeywordTools.cpp b/ApplicationCode/FileInterface/RifEclipseUserDataKeywordTools.cpp
index e72030d685..585174ebb1 100644
--- a/ApplicationCode/FileInterface/RifEclipseUserDataKeywordTools.cpp
+++ b/ApplicationCode/FileInterface/RifEclipseUserDataKeywordTools.cpp
@@ -183,6 +183,7 @@ RifEclipseSummaryAddress
     int         cellK             = -1;
     int         aquiferNumber     = -1;
     bool        isErrorResult     = false;
+    int         id                = -1;
 
     switch ( category )
     {
@@ -292,7 +293,8 @@ RifEclipseSummaryAddress
                                      cellJ,
                                      cellK,
                                      aquiferNumber,
-                                     isErrorResult );
+                                     isErrorResult,
+                                     id );
 }
 
 //--------------------------------------------------------------------------------------------------
diff --git a/ApplicationCode/FileInterface/RifKeywordVectorUserData.cpp b/ApplicationCode/FileInterface/RifKeywordVectorUserData.cpp
index afd37e8c50..3b4b12ffa5 100644
--- a/ApplicationCode/FileInterface/RifKeywordVectorUserData.cpp
+++ b/ApplicationCode/FileInterface/RifKeywordVectorUserData.cpp
@@ -168,7 +168,8 @@ bool RifKeywordVectorUserData::parse( const QString& data, const QString& custom
                                                    -1,
                                                    -1,
                                                    -1,
-                                                   false );
+                                                   false,
+                                                   -1 );
 
                     m_allResultAddresses.insert( addr );
 
diff --git a/ApplicationCode/FileInterface/RifReaderEclipseSummary.cpp b/ApplicationCode/FileInterface/RifReaderEclipseSummary.cpp
index fabe412630..202779b3ea 100644
--- a/ApplicationCode/FileInterface/RifReaderEclipseSummary.cpp
+++ b/ApplicationCode/FileInterface/RifReaderEclipseSummary.cpp
@@ -288,6 +288,7 @@ RifEclipseSummaryAddress addressFromErtSmSpecNode( const ecl::smspec_node& ertSu
     int                                          cellK( -1 );
     int                                          aquiferNumber( -1 );
     bool                                         isErrorResult( false );
+    int                                          id( -1 );
 
     quantityName = stringFromPointer( ertSumVarNode.get_keyword() );
 
@@ -414,7 +415,8 @@ RifEclipseSummaryAddress addressFromErtSmSpecNode( const ecl::smspec_node& ertSu
                                      cellJ,
                                      cellK,
                                      aquiferNumber,
-                                     isErrorResult );
+                                     isErrorResult,
+                                     id );
 }
 
 //--------------------------------------------------------------------------------------------------
diff --git a/ApplicationCode/FileInterface/RifReaderObservedData.cpp b/ApplicationCode/FileInterface/RifReaderObservedData.cpp
index aabb196ebf..edee985544 100644
--- a/ApplicationCode/FileInterface/RifReaderObservedData.cpp
+++ b/ApplicationCode/FileInterface/RifReaderObservedData.cpp
@@ -164,6 +164,7 @@ RifEclipseSummaryAddress RifReaderObservedData::address( const QString&
     int         cellK( -1 );
     int         aquiferNumber( -1 );
     bool        isErrorResult( false );
+    int         id( -1 );
 
     switch ( summaryCategory )
     {
@@ -192,7 +193,8 @@ RifEclipseSummaryAddress RifReaderObservedData::address( const QString&
                                      cellJ,
                                      cellK,
                                      aquiferNumber,
-                                     isErrorResult );
+                                     isErrorResult,
+                                     id );
 }
 
 //--------------------------------------------------------------------------------------------------
diff --git a/ApplicationCode/ProjectDataModel/RimProject.cpp b/ApplicationCode/ProjectDataModel/RimProject.cpp
index 2f2e2f5e97..71d7f64797 100644
--- a/ApplicationCode/ProjectDataModel/RimProject.cpp
+++ b/ApplicationCode/ProjectDataModel/RimProject.cpp
@@ -65,6 +65,7 @@
 #include "RimRftPlotCollection.h"
 #include "RimSaturationPressurePlotCollection.h"
 #include "RimScriptCollection.h"
+#include "RimSummaryCalculation.h"
 #include "RimSummaryCalculationCollection.h"
 #include "RimSummaryCaseMainCollection.h"
 #include "RimSummaryCrossPlotCollection.h"
@@ -106,6 +107,7 @@ RimProject::RimProject( void )
     , m_nextValidCaseGroupId( 0 )
     , m_nextValidViewId( 1 )
     , m_nextValidPlotId( 1 )
+    , m_nextValidCalculationId( 1 )
 {
     CAF_PDM_InitObject( "Project", "", "", "" );
 
@@ -243,10 +245,11 @@ void RimProject::close()
     plotWindowCurrentModelIndexPath = "";
     plotWindowTreeViewState         = "";
 
-    m_nextValidCaseId      = 0;
-    m_nextValidCaseGroupId = 0;
-    m_nextValidViewId      = 1;
-    m_nextValidPlotId      = 1;
+    m_nextValidCaseId        = 0;
+    m_nextValidCaseGroupId   = 0;
+    m_nextValidViewId        = 1;
+    m_nextValidPlotId        = 1;
+    m_nextValidCalculationId = 1;
 }
 
 //--------------------------------------------------------------------------------------------------
@@ -539,6 +542,22 @@ void RimProject::assignPlotIdToPlotWindow( RimPlotWindow* plotWindow )
     }
 }
 
+//--------------------------------------------------------------------------------------------------
+///
+//--------------------------------------------------------------------------------------------------
+void RimProject::assignCalculationIdToCalculation( RimSummaryCalculation* calculation )
+{
+    if ( calculation )
+    {
+        for ( RimSummaryCalculation* existingCalculation : calculationCollection->calculations() )
+        {
+            m_nextValidCalculationId = std::max( m_nextValidCalculationId, existingCalculation->id() + 1 );
+        }
+
+        calculation->setId( m_nextValidCalculationId++ );
+    }
+}
+
 //--------------------------------------------------------------------------------------------------
 ///
 //--------------------------------------------------------------------------------------------------
diff --git a/ApplicationCode/ProjectDataModel/RimProject.h b/ApplicationCode/ProjectDataModel/RimProject.h
index 302851a3a9..dcbbd53068 100644
--- a/ApplicationCode/ProjectDataModel/RimProject.h
+++ b/ApplicationCode/ProjectDataModel/RimProject.h
@@ -39,6 +39,7 @@ class RimTextAnnotation;
 class RimReachCircleAnnotation;
 class RimPolylinesAnnotation;
 class RimSummaryCalculationCollection;
+class RimSummaryCalculation;
 class RimCase;
 class RimCommandObject;
 class RimCommandObject;
@@ -119,6 +120,7 @@ public:
     void assignIdToCaseGroup( RimIdenticalGridCaseGroup* caseGroup );
     void assignViewIdToView( Rim3dView* view );
     void assignPlotIdToPlotWindow( RimPlotWindow* plotWindow );
+    void assignCalculationIdToCalculation( RimSummaryCalculation* calculation );
 
     void allCases( std::vector<RimCase*>& cases ) const;
 
@@ -207,6 +209,7 @@ private:
     int m_nextValidCaseGroupId;
     int m_nextValidViewId;
     int m_nextValidPlotId;
+    int m_nextValidCalculationId;
 
     caf::PdmChildArrayField<RimEclipseCase*>            casesObsolete; // obsolete
     caf::PdmChildArrayField<RimIdenticalGridCaseGroup*> caseGroupsObsolete; // obsolete
diff --git a/ApplicationCode/ProjectDataModel/RimSummaryCalculation.cpp b/ApplicationCode/ProjectDataModel/RimSummaryCalculation.cpp
index d6f91c7a62..429b2c027e 100644
--- a/ApplicationCode/ProjectDataModel/RimSummaryCalculation.cpp
+++ b/ApplicationCode/ProjectDataModel/RimSummaryCalculation.cpp
@@ -64,6 +64,8 @@ RimSummaryCalculation::RimSummaryCalculation()
     CAF_PDM_InitFieldNoDefault( &m_calculatedValues, "CalculatedValues", "Calculated Values", "", "", "" );
 
     CAF_PDM_InitFieldNoDefault( &m_timesteps, "TimeSteps", "Time Steps", "", "", "" );
+    CAF_PDM_InitField( &m_id, "Id", -1, "Id", "", "", "" );
+    m_id.uiCapability()->setUiHidden( true );
 
     m_exprContextMenuMgr = std::unique_ptr<RiuExpressionContextMenuManager>( new RiuExpressionContextMenuManager() );
 
@@ -86,6 +88,22 @@ QString RimSummaryCalculation::description() const
     return m_description;
 }
 
+//--------------------------------------------------------------------------------------------------
+///
+//--------------------------------------------------------------------------------------------------
+void RimSummaryCalculation::setId( int id )
+{
+    m_id = id;
+}
+
+//--------------------------------------------------------------------------------------------------
+///
+//--------------------------------------------------------------------------------------------------
+int RimSummaryCalculation::id() const
+{
+    return m_id;
+}
+
 //--------------------------------------------------------------------------------------------------
 ///
 //--------------------------------------------------------------------------------------------------
@@ -478,3 +496,15 @@ void RimSummaryCalculation::updateDependentCurvesAndPlots()
         }
     }
 }
+
+//--------------------------------------------------------------------------------------------------
+///
+//--------------------------------------------------------------------------------------------------
+std::vector<RimSummaryCalculationVariable*> RimSummaryCalculation::allVariables() const
+{
+    std::vector<RimSummaryCalculationVariable*> outVariables;
+    for ( RimSummaryCalculationVariable* v : m_variables )
+        outVariables.push_back( v );
+
+    return outVariables;
+}
diff --git a/ApplicationCode/ProjectDataModel/RimSummaryCalculation.h b/ApplicationCode/ProjectDataModel/RimSummaryCalculation.h
index 8a98540468..8e3b4a5de9 100644
--- a/ApplicationCode/ProjectDataModel/RimSummaryCalculation.h
+++ b/ApplicationCode/ProjectDataModel/RimSummaryCalculation.h
@@ -42,10 +42,15 @@ public:
     void    setDescription( const QString& description );
     QString description() const;
 
+    void setId( int id );
+    int  id() const;
+
     bool isDirty() const;
 
     caf::PdmChildArrayFieldHandle* variables();
 
+    std::vector<RimSummaryCalculationVariable*> allVariables() const;
+
     const std::vector<double>& values() const;
     const std::vector<time_t>& timeSteps() const;
 
@@ -85,6 +90,7 @@ private:
 
     caf::PdmField<std::vector<double>> m_calculatedValues;
     caf::PdmField<std::vector<time_t>> m_timesteps;
+    caf::PdmField<int>                 m_id;
 
     std::unique_ptr<RiuExpressionContextMenuManager> m_exprContextMenuMgr;
 
diff --git a/ApplicationCode/ProjectDataModel/RimSummaryCalculationCollection.cpp b/ApplicationCode/ProjectDataModel/RimSummaryCalculationCollection.cpp
index d7ecbad5cb..e053c7336d 100644
--- a/ApplicationCode/ProjectDataModel/RimSummaryCalculationCollection.cpp
+++ b/ApplicationCode/ProjectDataModel/RimSummaryCalculationCollection.cpp
@@ -18,7 +18,10 @@
 
 #include "RimSummaryCalculationCollection.h"
 
+#include "RiaApplication.h"
+
 #include "RimCalculatedSummaryCase.h"
+#include "RimProject.h"
 #include "RimSummaryCalculation.h"
 
 #include "cafPdmUiGroup.h"
@@ -46,8 +49,9 @@ RimSummaryCalculationCollection::RimSummaryCalculationCollection()
 RimSummaryCalculation* RimSummaryCalculationCollection::addCalculation()
 {
     RimSummaryCalculation* calculation = new RimSummaryCalculation;
+    RiaApplication::instance()->project()->assignCalculationIdToCalculation( calculation );
 
-    QString varName = QString( "Calculation_%1" ).arg( m_calcuations.size() + 1 );
+    QString varName = QString( "Calculation_%1" ).arg( calculation->id() );
     calculation->setDescription( varName );
     calculation->setExpression( varName + " := x + y" );
     calculation->parseExpression();
diff --git a/ApplicationCode/ProjectDataModel/Summary/RimCalculatedSummaryCurveReader.cpp b/ApplicationCode/ProjectDataModel/Summary/RimCalculatedSummaryCurveReader.cpp
index cc10cd052f..9d66565d41 100644
--- a/ApplicationCode/ProjectDataModel/Summary/RimCalculatedSummaryCurveReader.cpp
+++ b/ApplicationCode/ProjectDataModel/Summary/RimCalculatedSummaryCurveReader.cpp
@@ -85,7 +85,8 @@ void RifCalculatedSummaryCurveReader::buildMetaData()
 
     for ( RimSummaryCalculation* calc : m_calculationCollection->calculations() )
     {
-        m_allResultAddresses.insert( RifEclipseSummaryAddress::calculatedAddress( calc->description().toStdString() ) );
+        m_allResultAddresses.insert(
+            RifEclipseSummaryAddress::calculatedAddress( calc->description().toStdString(), calc->id() ) );
     }
 }
 
@@ -97,11 +98,10 @@ RimSummaryCalculation*
 {
     if ( m_calculationCollection && resultAddress.category() == RifEclipseSummaryAddress::SUMMARY_CALCULATED )
     {
-        QString calculatedName = QString::fromStdString( resultAddress.quantityName() );
-
+        int id = resultAddress.id();
         for ( RimSummaryCalculation* calc : m_calculationCollection->calculations() )
         {
-            if ( calc->description() == calculatedName )
+            if ( calc->id() == id )
             {
                 return calc;
             }
diff --git a/ApplicationCode/ProjectDataModel/Summary/RimSummaryAddress.cpp b/ApplicationCode/ProjectDataModel/Summary/RimSummaryAddress.cpp
index 152f72d413..53e85fe058 100644
--- a/ApplicationCode/ProjectDataModel/Summary/RimSummaryAddress.cpp
+++ b/ApplicationCode/ProjectDataModel/Summary/RimSummaryAddress.cpp
@@ -65,6 +65,7 @@ RimSummaryAddress::RimSummaryAddress()
     CAF_PDM_InitFieldNoDefault( &m_cellK, "SummaryCellK", "K", "", "", "" );
     CAF_PDM_InitFieldNoDefault( &m_aquiferNumber, "SummaryAquifer", "Aquifer", "", "", "" );
     CAF_PDM_InitFieldNoDefault( &m_isErrorResult, "IsErrorResult", "Is Error Result", "", "", "" );
+    CAF_PDM_InitFieldNoDefault( &m_calculationId, "CalculationId", "Calculation Id", "", "", "" );
 
     m_category          = RifEclipseSummaryAddress::SUMMARY_INVALID;
     m_regionNumber      = -1;
@@ -75,6 +76,7 @@ RimSummaryAddress::RimSummaryAddress()
     m_cellK             = -1;
     m_aquiferNumber     = -1;
     m_isErrorResult     = false;
+    m_calculationId     = -1;
 }
 
 //--------------------------------------------------------------------------------------------------
@@ -98,9 +100,10 @@ void RimSummaryAddress::setAddress( const RifEclipseSummaryAddress& addr )
     m_aquiferNumber     = addr.aquiferNumber();
     m_isErrorResult     = addr.isErrorResult();
 
-    m_cellI = addr.cellI();
-    m_cellJ = addr.cellJ();
-    m_cellK = addr.cellK();
+    m_cellI         = addr.cellI();
+    m_cellJ         = addr.cellJ();
+    m_cellK         = addr.cellK();
+    m_calculationId = addr.id();
 }
 
 //--------------------------------------------------------------------------------------------------
@@ -120,5 +123,6 @@ RifEclipseSummaryAddress RimSummaryAddress::address()
                                      m_cellJ(),
                                      m_cellK(),
                                      m_aquiferNumber,
-                                     m_isErrorResult );
+                                     m_isErrorResult,
+                                     m_calculationId );
 }
diff --git a/ApplicationCode/ProjectDataModel/Summary/RimSummaryAddress.h b/ApplicationCode/ProjectDataModel/Summary/RimSummaryAddress.h
index 5552a35aca..549e8dd40f 100644
--- a/ApplicationCode/ProjectDataModel/Summary/RimSummaryAddress.h
+++ b/ApplicationCode/ProjectDataModel/Summary/RimSummaryAddress.h
@@ -62,4 +62,5 @@ private:
     caf::PdmField<int>                                                        m_cellK;
     caf::PdmField<int>                                                        m_aquiferNumber;
     caf::PdmField<bool>                                                       m_isErrorResult;
+    caf::PdmField<int>                                                        m_calculationId;
 };
diff --git a/ApplicationCode/UnitTests/ObservedDataParser-Test.cpp b/ApplicationCode/UnitTests/ObservedDataParser-Test.cpp
index ac693d07b0..5602ebd401 100644
--- a/ApplicationCode/UnitTests/ObservedDataParser-Test.cpp
+++ b/ApplicationCode/UnitTests/ObservedDataParser-Test.cpp
@@ -569,7 +569,7 @@ TEST( RifColumnBasedRsmspecParserTest, TestTableValues )
     userData.parse( data );
 
     RifEclipseSummaryAddress
-        adr( RifEclipseSummaryAddress::SUMMARY_WELL, "WOPR", -1, -1, "", "P-15P", -1, "", -1, -1, -1, -1, false );
+        adr( RifEclipseSummaryAddress::SUMMARY_WELL, "WOPR", -1, -1, "", "P-15P", -1, "", -1, -1, -1, -1, false, -1 );
 
     QDateTime firstTimeStep = RiaQDateTimeTools::addDays( RiaQDateTimeTools::epoch(), 1.0 );
     auto      timeSteps     = userData.timeSteps( adr );
diff --git a/ApplicationCode/UserInterface/RiuSummaryCurveDefSelection.cpp b/ApplicationCode/UserInterface/RiuSummaryCurveDefSelection.cpp
index 9bd8b5ec5d..2a8af4ffda 100644
--- a/ApplicationCode/UserInterface/RiuSummaryCurveDefSelection.cpp
+++ b/ApplicationCode/UserInterface/RiuSummaryCurveDefSelection.cpp
@@ -138,7 +138,8 @@ RiuSummaryCurveDefSelection::RiuSummaryCurveDefSelection()
             {new SummaryIdentifierAndField( RifEclipseSummaryAddress::INPUT_CELL_IJK )},
             {new SummaryIdentifierAndField( RifEclipseSummaryAddress::INPUT_VECTOR_NAME )}}},
           {RifEclipseSummaryAddress::SUMMARY_CALCULATED,
-           {{new SummaryIdentifierAndField( RifEclipseSummaryAddress::INPUT_VECTOR_NAME )}}},
+           {{new SummaryIdentifierAndField( RifEclipseSummaryAddress::INPUT_ID )},
+            {new SummaryIdentifierAndField( RifEclipseSummaryAddress::INPUT_VECTOR_NAME )}}},
           {RifEclipseSummaryAddress::SUMMARY_IMPORTED,
            {{new SummaryIdentifierAndField( RifEclipseSummaryAddress::INPUT_VECTOR_NAME )}}},
       } )
@@ -350,6 +351,13 @@ RiuSummaryCurveDefSelection::RiuSummaryCurveDefSelection()
                                 "" );
 
     CAF_PDM_InitFieldNoDefault( m_identifierFieldsMap[RifEclipseSummaryAddress::SUMMARY_CALCULATED][0]->pdmField(),
+                                "CalculatedVectorsId",
+                                "Calculated Vectors Id",
+                                "",
+                                "",
+                                "" );
+
+    CAF_PDM_InitFieldNoDefault( m_identifierFieldsMap[RifEclipseSummaryAddress::SUMMARY_CALCULATED][1]->pdmField(),
                                 "CalculatedVectors",
                                 "Calculated Vectors",
                                 "",
@@ -940,7 +948,7 @@ void RiuSummaryCurveDefSelection::defineUiOrdering( QString uiConfigName, caf::P
     }
     else if ( sumCategory == RifEclipseSummaryAddress::SUMMARY_CALCULATED )
     {
-        summaryiesField = m_identifierFieldsMap[RifEclipseSummaryAddress::SUMMARY_CALCULATED][0]->pdmField();
+        summaryiesField = m_identifierFieldsMap[RifEclipseSummaryAddress::SUMMARY_CALCULATED][1]->pdmField();
     }
     else if ( sumCategory == RifEclipseSummaryAddress::SUMMARY_IMPORTED )
     {