diff --git a/ra-optimisation/search-tree-rao/src/main/java/com/powsybl/openrao/searchtreerao/linearoptimisation/algorithms/fillers/AbstractCoreProblemFiller.java b/ra-optimisation/search-tree-rao/src/main/java/com/powsybl/openrao/searchtreerao/linearoptimisation/algorithms/fillers/AbstractCoreProblemFiller.java
index e793940b3f..d57970a023 100644
--- a/ra-optimisation/search-tree-rao/src/main/java/com/powsybl/openrao/searchtreerao/linearoptimisation/algorithms/fillers/AbstractCoreProblemFiller.java
+++ b/ra-optimisation/search-tree-rao/src/main/java/com/powsybl/openrao/searchtreerao/linearoptimisation/algorithms/fillers/AbstractCoreProblemFiller.java
@@ -59,6 +59,7 @@ public abstract class AbstractCoreProblemFiller implements ProblemFiller {
     protected final boolean raRangeShrinking;
     protected final PstModel pstModel;
     protected final OffsetDateTime timestamp;
+    private final Map<RangeAction<?>, Set<RangeAction<?>>> memoizedSameRangeActions = new HashMap<>();
 
     protected AbstractCoreProblemFiller(OptimizationPerimeter optimizationContext,
                                         RangeActionSetpointResult prePerimeterRangeActionSetpoints,
@@ -409,6 +410,9 @@ protected static List<Double> getMinAndMaxAbsoluteAndRelativeSetpoints(RangeActi
     }
 
     private Set<RangeAction<?>> getAvailableRangeActionsOnSameAction(RangeAction<?> rangeAction) {
+        if (memoizedSameRangeActions.containsKey(rangeAction)) {
+            return memoizedSameRangeActions.get(rangeAction);
+        }
         Set<RangeAction<?>> rangeActions = new HashSet<>();
         optimizationContext.getRangeActionsPerState().forEach((state, raSet) ->
             raSet.forEach(ra -> {
@@ -417,6 +421,7 @@ private Set<RangeAction<?>> getAvailableRangeActionsOnSameAction(RangeAction<?>
                 }
             })
         );
+        memoizedSameRangeActions.put(rangeAction, rangeActions);
         return rangeActions;
     }
 
diff --git a/ra-optimisation/search-tree-rao/src/main/java/com/powsybl/openrao/searchtreerao/result/impl/RangeActionActivationResultImpl.java b/ra-optimisation/search-tree-rao/src/main/java/com/powsybl/openrao/searchtreerao/result/impl/RangeActionActivationResultImpl.java
index 81ac5cf8dc..37107a1d3e 100644
--- a/ra-optimisation/search-tree-rao/src/main/java/com/powsybl/openrao/searchtreerao/result/impl/RangeActionActivationResultImpl.java
+++ b/ra-optimisation/search-tree-rao/src/main/java/com/powsybl/openrao/searchtreerao/result/impl/RangeActionActivationResultImpl.java
@@ -27,9 +27,10 @@ public class RangeActionActivationResultImpl implements RangeActionActivationRes
 
     private final Map<RangeAction<?>, ElementaryResult> elementaryResultMap = new HashMap<>();
 
-    boolean shouldRecomputeSetpointsPerState = true;
+    boolean shouldRecomputeSetpointsPerState;
 
     private Map<String, Map<State, Double> > setpointPerStatePerPstId;
+    private Map<State, Optional<State>> memoizedPreviousState = new HashMap<>();
 
     private static class ElementaryResult {
         private final double refSetpoint;
@@ -81,6 +82,7 @@ public RangeActionActivationResultImpl(RangeActionSetpointResult rangeActionSetp
     public void putResult(RangeAction<?> rangeAction, State state, double setpoint) {
         shouldRecomputeSetpointsPerState = true;
         elementaryResultMap.get(rangeAction).put(state, setpoint);
+        memoizedPreviousState = new HashMap<>();
     }
 
     private synchronized void computeSetpointsPerStatePerPst() {
@@ -202,10 +204,15 @@ public int getTapVariation(PstRangeAction pstRangeAction, State state) {
     }
 
     private Optional<State> getPreviousState(State state) {
-        return elementaryResultMap.values().stream()
+        if (memoizedPreviousState.containsKey(state)) {
+            return memoizedPreviousState.get(state);
+        }
+        Optional<State> previousState = elementaryResultMap.values().stream()
             .flatMap(eR -> eR.getAllStatesWithActivation().stream())
             .filter(s -> s.getContingency().equals(state.getContingency()) || s.getContingency().isEmpty())
             .filter(s -> s.getInstant().comesBefore(state.getInstant()))
             .max(Comparator.comparingInt(s -> s.getInstant().getOrder()));
+        memoizedPreviousState.put(state, previousState);
+        return previousState;
     }
 }
diff --git a/tests/src/test/java/com/powsybl/openrao/tests/steps/InterTemporalRaoSteps.java b/tests/src/test/java/com/powsybl/openrao/tests/steps/InterTemporalRaoSteps.java
index e599fefeb0..16d262020f 100644
--- a/tests/src/test/java/com/powsybl/openrao/tests/steps/InterTemporalRaoSteps.java
+++ b/tests/src/test/java/com/powsybl/openrao/tests/steps/InterTemporalRaoSteps.java
@@ -103,4 +103,4 @@ public static void loadDataForInterTemporalRao(DataTable arg1) throws IOExceptio
     public static void iLaunchMarmot() {
         InterTemporalRao.run(interTemporalRaoInput, CommonTestData.getRaoParameters());
     }
-}
\ No newline at end of file
+}