diff --git a/src/solver/modeler/dataSeries/CMakeLists.txt b/src/solver/modeler/dataSeries/CMakeLists.txt
index 180ab3dcbc..d3c6b21d5e 100644
--- a/src/solver/modeler/dataSeries/CMakeLists.txt
+++ b/src/solver/modeler/dataSeries/CMakeLists.txt
@@ -9,6 +9,8 @@ set(SRC_DATA_SERIES
 
         include/antares/solver/modeler/dataSeries/dataSeriesRepo.h
         dataSeriesRepo.cpp
+        include/antares/solver/modeler/dataSeries/dataSeriesRepoExceptions.h
+        dataSeriesRepoExceptions.cpp
 
         include/antares/solver/modeler/dataSeries/scenarioGroupRepo.h
         scenarioGroupRepo.cpp
diff --git a/src/solver/modeler/dataSeries/dataSeriesRepo.cpp b/src/solver/modeler/dataSeries/dataSeriesRepo.cpp
index c82e8fe64d..6be71f7479 100644
--- a/src/solver/modeler/dataSeries/dataSeriesRepo.cpp
+++ b/src/solver/modeler/dataSeries/dataSeriesRepo.cpp
@@ -2,26 +2,29 @@
 
 #include <stdexcept>
 
+#include "antares/solver/modeler/dataSeries/dataSeriesRepoExceptions.h"
+
 namespace Antares::Solver::Modeler::DataSeries
 {
 void DataSeriesRepository::addDataSeries(std::unique_ptr<IDataSeries> dataSeries)
 {
     std::string name = dataSeries->name();
+    if (dataSeries_.contains(name))
+    {
+        throw DataSeriesRepo_DSalreadyExists(name);
+    }
     dataSeries_[name] = std::move(dataSeries);
 }
 
 IDataSeries& DataSeriesRepository::getDataSeries(const std::string& setId)
 {
-    std::string error_message = err_prefix;
     if (dataSeries_.empty())
     {
-        error_message += "empty";
-        throw std::invalid_argument(error_message);
+        throw DataSeriesRepo_Empty();
     }
     if (!dataSeries_.contains(setId))
     {
-        error_message += "data series '" + setId + "' does not exist";
-        throw std::invalid_argument(error_message);
+        throw DataSeriesRepo_DataSeriesNotExist(setId);
     }
     return *(dataSeries_[setId]);
 }
diff --git a/src/solver/modeler/dataSeries/dataSeriesRepoExceptions.cpp b/src/solver/modeler/dataSeries/dataSeriesRepoExceptions.cpp
new file mode 100644
index 0000000000..9e7a1e5eef
--- /dev/null
+++ b/src/solver/modeler/dataSeries/dataSeriesRepoExceptions.cpp
@@ -0,0 +1,22 @@
+#include "antares/solver/modeler/dataSeries/dataSeriesRepoExceptions.h"
+
+#include <string>
+
+namespace Antares::Solver::Modeler::DataSeries
+{
+DataSeriesRepo_Empty::DataSeriesRepo_Empty():
+    std::invalid_argument("Data series repo is empty, and somebody requests data from it")
+{
+}
+
+DataSeriesRepo_DataSeriesNotExist::DataSeriesRepo_DataSeriesNotExist(const std::string setId):
+    std::invalid_argument("Data series repo : data series '" + setId + "' does not exist")
+{
+}
+
+DataSeriesRepo_DSalreadyExists::DataSeriesRepo_DSalreadyExists(const std::string setId):
+    std::invalid_argument("Data series repo : data series '" + setId + "' already exists")
+{
+}
+
+} // namespace Antares::Solver::Modeler::DataSeries
diff --git a/src/solver/modeler/dataSeries/include/antares/solver/modeler/dataSeries/dataSeriesRepo.h b/src/solver/modeler/dataSeries/include/antares/solver/modeler/dataSeries/dataSeriesRepo.h
index ab6bf12e0f..9eb8bc8a09 100644
--- a/src/solver/modeler/dataSeries/include/antares/solver/modeler/dataSeries/dataSeriesRepo.h
+++ b/src/solver/modeler/dataSeries/include/antares/solver/modeler/dataSeries/dataSeriesRepo.h
@@ -18,7 +18,6 @@ class DataSeriesRepository
 
 private:
     std::map<std::string, std::unique_ptr<IDataSeries>> dataSeries_;
-    std::string err_prefix = "Data series repo : ";
 };
 
 } // namespace Antares::Solver::Modeler::DataSeries
diff --git a/src/solver/modeler/dataSeries/include/antares/solver/modeler/dataSeries/dataSeriesRepoExceptions.h b/src/solver/modeler/dataSeries/include/antares/solver/modeler/dataSeries/dataSeriesRepoExceptions.h
new file mode 100644
index 0000000000..6512ea098a
--- /dev/null
+++ b/src/solver/modeler/dataSeries/include/antares/solver/modeler/dataSeries/dataSeriesRepoExceptions.h
@@ -0,0 +1,23 @@
+#pragma once
+#include <stdexcept>
+
+namespace Antares::Solver::Modeler::DataSeries
+{
+class DataSeriesRepo_Empty: public std::invalid_argument
+{
+public:
+    DataSeriesRepo_Empty();
+};
+
+class DataSeriesRepo_DataSeriesNotExist: public std::invalid_argument
+{
+public:
+    DataSeriesRepo_DataSeriesNotExist(const std::string setId);
+};
+
+class DataSeriesRepo_DSalreadyExists: public std::invalid_argument
+{
+public:
+    DataSeriesRepo_DSalreadyExists(const std::string setId);
+};
+} // namespace Antares::Solver::Modeler::DataSeries
diff --git a/src/tests/src/solver/modeler/dataSeries/testDataSeriesRepo.cpp b/src/tests/src/solver/modeler/dataSeries/testDataSeriesRepo.cpp
index 34e1006f99..2e960e6b1f 100644
--- a/src/tests/src/solver/modeler/dataSeries/testDataSeriesRepo.cpp
+++ b/src/tests/src/solver/modeler/dataSeries/testDataSeriesRepo.cpp
@@ -5,7 +5,9 @@
 #include <boost/test/unit_test.hpp>
 
 #include <antares/solver/modeler/dataSeries/dataSeriesRepo.h>
+#include "antares/solver/modeler/dataSeries/dataSeriesRepoExceptions.h"
 #include "antares/solver/modeler/dataSeries/timeSeriesSet.h"
+#include "antares/solver/modeler/dataSeries/timeSeriesSetExceptions.h"
 
 using namespace Antares::Solver::Modeler::DataSeries;
 
@@ -13,9 +15,24 @@ BOOST_AUTO_TEST_CASE(repo_is_empty__asking_any_data_series_raises_exception)
 {
     DataSeriesRepository dataSeriesRepository;
 
-    std::string expected_err_msg = "Data series repo : empty";
+    std::string expected_err_msg = "Data series repo is empty, and somebody requests data from it";
     BOOST_CHECK_EXCEPTION(dataSeriesRepository.getDataSeries("dummy name"),
-                          std::invalid_argument,
+                          DataSeriesRepo_Empty,
+                          checkMessage(expected_err_msg));
+}
+
+BOOST_AUTO_TEST_CASE(adding_to_repo_a_data_it_already_contains___exception_raised)
+{
+    DataSeriesRepository dataSeriesRepository;
+    auto some_TS_set = std::make_unique<TimeSeriesSet>("some TS set", 5);
+    dataSeriesRepository.addDataSeries(std::move(some_TS_set));
+
+    // This TS set wears the same name as the previous one
+    auto some_other_TS_set = std::make_unique<TimeSeriesSet>("some TS set", 7);
+
+    std::string expected_err_msg = "Data series repo : data series 'some TS set' already exists";
+    BOOST_CHECK_EXCEPTION(dataSeriesRepository.addDataSeries(std::move(some_other_TS_set)),
+                          DataSeriesRepo_DSalreadyExists,
                           checkMessage(expected_err_msg));
 }
 
@@ -27,7 +44,7 @@ BOOST_AUTO_TEST_CASE(repo_not_empty__asking_nonexistent_data_raises_exception)
 
     std::string expected_err_msg = "Data series repo : data series 'dummy name' does not exist";
     BOOST_CHECK_EXCEPTION(dataSeriesRepository.getDataSeries("dummy name"),
-                          std::invalid_argument,
+                          DataSeriesRepo_DataSeriesNotExist,
                           checkMessage(expected_err_msg));
 }
 
@@ -57,7 +74,7 @@ BOOST_AUTO_TEST_CASE(asking_repo_data_for_a_too_big_hour___exception_from_data_s
     unsigned hour = 100; // Hour too big
     std::string expected_err_msg = "TS set 'some TS set' : hour 100 exceeds TS set's height";
     BOOST_CHECK_EXCEPTION(dataSeriesRepository.getDataSeries("some TS set").getData(rank, hour),
-                          std::invalid_argument,
+                          TSset_HourTooBig,
                           checkMessage(expected_err_msg));
 }