diff --git a/unit_tests/data/Test_TensorImpl.cpp b/unit_tests/data/Test_TensorImpl.cpp
index fd938f10a947d1520600a1d00022eeb970cd76e6..2bc1e7d4c6f8a7cfbae8807e3021f9c5dd89fff6 100644
--- a/unit_tests/data/Test_TensorImpl.cpp
+++ b/unit_tests/data/Test_TensorImpl.cpp
@@ -9,19 +9,23 @@
  *
  ********************************************************************************/
 
-#include <catch2/catch_test_macros.hpp>
-#include <cstddef>   // std::size_t
-#include <cstdint>   // std::uint16_t
-#include <chrono>
-#include <iostream>
+#include <chrono>      // std::micro, std::chrono::time_point,
+                       // std::chrono::system_clock
+#include <cstddef>     // std::size_t
+#include <cstdint>     // std::int32_t, std::uint16_t
 #include <memory>
-#include <numeric>   // std::accumulate
-#include <random>    // std::random_device, std::mt19937, std::uniform_real_distribution
+#include <random>      // std::random_device, std::mt19937
+                       // std::uniform_int_distribution, std::uniform_real_distribution
+#include <vector>
+
+#include <catch2/catch_test_macros.hpp>
+#include <fmt/core.h>
 
-#include "aidge/data/Tensor.hpp"
 #include "aidge/backend/cpu/data/TensorImpl.hpp"
-#include "aidge/operator/Add.hpp"
 #include "aidge/backend/cpu/operator/AddImpl.hpp"
+#include "aidge/data/Data.hpp"
+#include "aidge/operator/Add.hpp"
+#include "aidge/utils/ArrayHelpers.hpp"
 
 namespace Aidge {
 
@@ -35,8 +39,7 @@ TEST_CASE("Test addition of Tensors","[TensorImpl][Add][Data]") {
     std::uniform_int_distribution<int> boolDist(0,1);
 
     // Create MatMul Operator
-    std::shared_ptr<Node> mySub = Add();
-    auto op = std::static_pointer_cast<OperatorTensor>(mySub-> getOperator());
+    std::shared_ptr<Add_Op> op = std::make_shared<Add_Op>();
     op->setDataType(DataType::Float32);
     op->setBackend("cpu");
 
diff --git a/unit_tests/operator/Test_AddImpl.cpp b/unit_tests/operator/Test_AddImpl.cpp
index bca4025705cb1c851dcf3e9accbf016c4535120a..720c4ca2aa59ec3c265cc416871fa76c83dfc7fe 100644
--- a/unit_tests/operator/Test_AddImpl.cpp
+++ b/unit_tests/operator/Test_AddImpl.cpp
@@ -9,12 +9,16 @@
  *
  ********************************************************************************/
 
+#include <memory>
+
 #include <catch2/catch_test_macros.hpp>
 
+#include "aidge/backend/cpu/operator/AddImpl.hpp"
+#include "aidge/data/Data.hpp"
 #include "aidge/data/Tensor.hpp"
+#include "aidge/graph/Node.hpp"
 #include "aidge/operator/Add.hpp"
-
-#include "aidge/backend/cpu.hpp"
+#include "aidge/utils/ArrayHelpers.hpp"
 
 using namespace Aidge;
 
diff --git a/unit_tests/operator/Test_AndImpl.cpp b/unit_tests/operator/Test_AndImpl.cpp
index 053bb3ea4ed913bd388f3ae049c4d6402ad58d59..c2309dce5f32862ad9aeceaf98430b75ab7be6ef 100644
--- a/unit_tests/operator/Test_AndImpl.cpp
+++ b/unit_tests/operator/Test_AndImpl.cpp
@@ -9,13 +9,19 @@
  *
  ********************************************************************************/
 
+#include <cstddef> // std::size_t
+#include <cstdint> // std::uint16_t
+#include <memory>
+#include <random>  // std::random_device, std::mt19937, std::uniform_int_distribution, std::uniform_real_distribution
+
 #include <catch2/catch_test_macros.hpp>
-#include <random>    // std::random_device, std::mt19937, std::uniform_real_distribution
 
+#include "aidge/backend/cpu/operator/AndImpl.hpp"
+#include "aidge/data/Data.hpp"
 #include "aidge/data/Tensor.hpp"
+#include "aidge/graph/Node.hpp"
 #include "aidge/operator/And.hpp"
-
-#include "aidge/backend/cpu.hpp"
+#include "aidge/utils/ArrayHelpers.hpp"
 
 using namespace Aidge;
 
@@ -180,7 +186,7 @@ TEST_CASE("[cpu/operator] And(forward)", "[And][CPU]") {
         }                                       //
         });                                     //
 
-        std::shared_ptr<Tensor> input_2 = std::make_shared<Tensor>(Array1D<int,2> {{10, 20}});  
+        std::shared_ptr<Tensor> input_2 = std::make_shared<Tensor>(Array1D<int,2> {{10, 20}});
         std::shared_ptr<Tensor> expectedOutput = std::make_shared<Tensor>(Array4D<int,1,3,3,2> {
             {                                   //
                 {                               //
diff --git a/unit_tests/operator/Test_ArgMaxImpl.cpp b/unit_tests/operator/Test_ArgMaxImpl.cpp
index 9915d90423e976db1bdd2a694a2cfd7beb380cee..894697f65a6f73af27a568b994c1dd2dc6b118f3 100644
--- a/unit_tests/operator/Test_ArgMaxImpl.cpp
+++ b/unit_tests/operator/Test_ArgMaxImpl.cpp
@@ -9,17 +9,20 @@
  *
  ********************************************************************************/
 
-#include <catch2/catch_test_macros.hpp>
+#include <cstddef> // std::size_t
+#include <cstdint> // std::uint16_t
 #include <memory>
-#include <numeric>   // std::accumulate
-#include <random>    // std::random_device, std::mt19937, std::uniform_real_distribution
+#include <random>  // std::random_device, std::mt19937, std::uniform_int_distribution, std::uniform_real_distribution
+
+#include <catch2/catch_test_macros.hpp>
+#include <fmt/core.h>
 
+#include "aidge/backend/cpu/operator/ArgMaxImpl.hpp"
+#include "aidge/data/Data.hpp"
 #include "aidge/data/Tensor.hpp"
+#include "aidge/graph/Node.hpp"
 #include "aidge/operator/ArgMax.hpp"
-#include "aidge/operator/Conv.hpp"
-
-#include "aidge/backend/cpu.hpp"
-#include "aidge/utils/TensorUtils.hpp"
+#include "aidge/utils/ArrayHelpers.hpp"
 
 using namespace Aidge;
 
@@ -118,8 +121,8 @@ TEST_CASE("[cpu/operator] ArgMax(forward)", "[ArgMax][CPU]") {
         SECTION("Axis 2") {
 
             Tensor myOutput = Tensor(Array3D<float,2,3, 1> {
-               { 
-                    { 
+               {
+                    {
                         {3.0},
                         {2.0},
                         {1.0}
@@ -144,7 +147,7 @@ TEST_CASE("[cpu/operator] ArgMax(forward)", "[ArgMax][CPU]") {
         SECTION("Axis 2 with keep_dims false") {
 
             Tensor myOutput = Tensor(Array2D<float,2,3> {
-               { 
+               {
                     { 3.0, 2.0, 1.0 },
                     { 2.0, 1.0, 0.0 }
                }
@@ -196,10 +199,11 @@ TEST_CASE("[cpu/operator] ArgMax(forward)", "[ArgMax][CPU]") {
             op->associateInput(0,myInput);
             op->setDataType(DataType::Float32);
             op->setBackend("cpu");
-            std::cout << " ...............  "<< std::endl;
+            fmt::print("{:.^20}\n", "forward");
             myArgMax->forward();
+            fmt::print("{:.^20}\n", "result");
             op->getOutput(0)->print();
-            std::cout <<"------"<<std::endl;
+            fmt::print("{:.^20}\n", "truth");
             myOutput.print();
 
             REQUIRE(*(op->getOutput(0)) == myOutput);
diff --git a/unit_tests/operator/Test_Atan.cpp b/unit_tests/operator/Test_Atan.cpp
index 9548e35d81b0423125424a4198d82558c4e57df4..b9438db0b38642e8c49e46451544a68714ac4de6 100644
--- a/unit_tests/operator/Test_Atan.cpp
+++ b/unit_tests/operator/Test_Atan.cpp
@@ -9,14 +9,18 @@
  *
  ********************************************************************************/
 
+#include <cmath>    // std::abs
+#include <cstddef>  // std::size_t
+#include <memory>
+
 #include <catch2/catch_test_macros.hpp>
 
+#include "aidge/backend/cpu/operator/AtanImpl.hpp"
+#include "aidge/data/Data.hpp"
 #include "aidge/data/Tensor.hpp"
+#include "aidge/graph/Node.hpp"
 #include "aidge/operator/Atan.hpp"
-
-#include "aidge/backend/cpu.hpp"
-
-#include <memory>
+#include "aidge/utils/ArrayHelpers.hpp"
 
 using namespace Aidge;
 
@@ -32,7 +36,7 @@ TEST_CASE("[cpu/operator] Atan(forward)") {
              0.09486303, 0.16007232, 0.40421187, 0.4102045, 0.39055911}});
 
     std::shared_ptr<Node> myAtan = Atan();
-    auto op = std::static_pointer_cast<OperatorTensor>(myAtan->getOperator());
+    auto op = std::static_pointer_cast<Atan_Op>(myAtan->getOperator());
     op->associateInput(0, input0);
     op->setDataType(DataType::Float32);
     op->setBackend("cpu");
@@ -61,7 +65,7 @@ TEST_CASE("[cpu/operator] Atan(forward)") {
                                   {0.75377332, 0.77411225, 0.32928031}}}});
 
     std::shared_ptr<Node> myAtan = Atan();
-    auto op = std::static_pointer_cast<OperatorTensor>(myAtan->getOperator());
+    auto op = std::static_pointer_cast<Atan_Op>(myAtan->getOperator());
     op->associateInput(0, input0);
     op->setDataType(DataType::Float32);
     op->setBackend("cpu");
diff --git a/unit_tests/operator/Test_AvgPoolingImpl.cpp b/unit_tests/operator/Test_AvgPoolingImpl.cpp
index aaa2757830c245275d02792a7a5a2eb1db32d7b8..372febc61d04c2ba983dd33f009fe5bf1d2908a0 100644
--- a/unit_tests/operator/Test_AvgPoolingImpl.cpp
+++ b/unit_tests/operator/Test_AvgPoolingImpl.cpp
@@ -9,14 +9,18 @@
  *
  ********************************************************************************/
 
-#include <catch2/catch_test_macros.hpp>
+#include <cmath>    // std::abs
+#include <cstddef>  // std::size_t
 #include <memory>
-#include <cstdlib>
 
+#include <catch2/catch_test_macros.hpp>
+
+#include "aidge/backend/cpu/operator/AvgPoolingImpl.hpp"
+#include "aidge/data/Data.hpp"
 #include "aidge/data/Tensor.hpp"
+#include "aidge/graph/Node.hpp"
 #include "aidge/operator/AvgPooling.hpp"
-
-#include "aidge/backend/cpu.hpp"
+#include "aidge/utils/ArrayHelpers.hpp"
 
 using namespace Aidge;
 
@@ -53,7 +57,7 @@ TEST_CASE("[cpu/operator] AvgPooling(forward)", "[AvgPooling][CPU]") {
     });
     SECTION("Stride") {
         std::shared_ptr<Node> myAvgPool = AvgPooling({2,2}, "mycdw", {2,2});
-        auto op = std::static_pointer_cast<OperatorTensor>(myAvgPool -> getOperator());
+        auto op = std::static_pointer_cast<AvgPooling_Op<2>>(myAvgPool -> getOperator());
 
         std::shared_ptr<Tensor> myOutput = std::make_shared<Tensor>(Array4D<float,2,2,2,2> {
             {
@@ -90,7 +94,7 @@ TEST_CASE("[cpu/operator] AvgPooling(forward)", "[AvgPooling][CPU]") {
         }
         });
         std::shared_ptr<Node> myAvgPool = AvgPooling({3,3}, "mycdw", {3,3});
-        auto op = std::static_pointer_cast<OperatorTensor>(myAvgPool -> getOperator());
+        auto op = std::static_pointer_cast<AvgPooling_Op<2>>(myAvgPool -> getOperator());
 
         Tensor myOutput = Array4D<float,1,1,1,1> {
             {{{{(0.3745 + 0.9507 + 0.7320 + 0.5987 + 0.1560 + 0.1560 + 0.0581 + 0.8662 + 0.6011)/9.0}}}}
diff --git a/unit_tests/operator/Test_BatchNormImpl.cpp b/unit_tests/operator/Test_BatchNormImpl.cpp
index 1b42c90dd09d63cd319f19bd29751da816db06c0..26e964f9386e19a6070d75a4106b6b46a29e455d 100644
--- a/unit_tests/operator/Test_BatchNormImpl.cpp
+++ b/unit_tests/operator/Test_BatchNormImpl.cpp
@@ -9,20 +9,24 @@
  *
  ********************************************************************************/
 
-#include <catch2/catch_test_macros.hpp>
+#include <cmath>    // std::abs
+#include <cstddef>  // std::size_t
 #include <memory>
 
+#include <catch2/catch_test_macros.hpp>
+
+#include "aidge/backend/cpu/operator/BatchNormImpl.hpp"
+#include "aidge/data/Data.hpp"
 #include "aidge/data/Tensor.hpp"
+#include "aidge/graph/Node.hpp"
 #include "aidge/operator/BatchNorm.hpp"
-#include "aidge/scheduler/SequentialScheduler.hpp"
-
-#include "aidge/backend/cpu.hpp"
+#include "aidge/utils/ArrayHelpers.hpp"
 
 using namespace Aidge;
 
 TEST_CASE("[cpu/operator] BatchNorm(forward)", "[BatchNorm][CPU]") {
     std::shared_ptr<Node> myBatchNorm = BatchNorm<2>(3, 0.00001F, 0.1F, "mybatchnorm");
-    auto op = std::static_pointer_cast<OperatorTensor>(myBatchNorm -> getOperator());
+    auto op = std::static_pointer_cast<BatchNorm_Op<2>>(myBatchNorm -> getOperator());
     std::shared_ptr<Tensor> myWeights = std::make_shared<Tensor>(Array1D<float,3> {{0.9044, 0.3028, 0.0218}});
     std::shared_ptr<Tensor> myBias = std::make_shared<Tensor>(Array1D<float,3> {{0.1332, 0.7503, 0.0878}});
     std::shared_ptr<Tensor> myMean = std::make_shared<Tensor>(Array1D<float,3> {{0.9931, 0.8421, 0.9936}});
diff --git a/unit_tests/operator/Test_BitShift.cpp b/unit_tests/operator/Test_BitShift.cpp
index a52990bc7991a325ce151cf6634b0d5a831992c8..db97e8d30b5e7121b096f99f8722a69e6d4e367c 100644
--- a/unit_tests/operator/Test_BitShift.cpp
+++ b/unit_tests/operator/Test_BitShift.cpp
@@ -9,15 +9,20 @@
  *
  ********************************************************************************/
 
-#include <catch2/catch_test_macros.hpp>
+#include <chrono>      // std::micro, std::chrono::time_point,
+                       // std::chrono::system_clock
 #include <cstddef>   // std::size_t
 #include <cstdint>   // std::uint16_t
 #include <chrono>
-#include <iostream>
 #include <memory>
-#include <numeric>   
+#include <numeric>
 #include <random>    // std::random_device, std::mt19937, std::uniform_real_distribution
-#include <iomanip>
+
+#include <catch2/catch_test_macros.hpp>
+#include <fmt/core.h>
+
+#include "aidge/backend/cpu/data/TensorImpl.hpp"
+#include "aidge/backend/cpu/operator/BitShiftImpl.hpp"
 #include "aidge/data/Tensor.hpp"
 #include "aidge/operator/BitShift.hpp"
 #include "aidge/utils/TensorUtils.hpp"
@@ -29,7 +34,7 @@ TEST_CASE("[cpu/operator] BitShift_TEST", "[BitShift][CPU]") {
     // Create a random number generator
     std::random_device rd;
     std::mt19937 gen(rd());
-    std::uniform_int_distribution<int> valueDist(-15, 15); 
+    std::uniform_int_distribution<int> valueDist(-15, 15);
     std::uniform_int_distribution<std::size_t> dimSizeDist(std::size_t(2), std::size_t(5));
     std::uniform_int_distribution<std::size_t> nbDimsDist(std::size_t(1), std::size_t(3));
     std::uniform_int_distribution<int> boolDist(0,1);
@@ -131,8 +136,8 @@ TEST_CASE("[cpu/operator] BitShift_TEST", "[BitShift][CPU]") {
 
 
             }
-            std::cout << "number of elements over time spent: " << (number_of_operation / duration.count())<< std::endl;
-            std::cout << "total time: " << duration.count() << "μs" << std::endl;
+            fmt::print("INFO: number of elements over time spent: {}\n", (number_of_operation / duration.count()));
+            fmt::print("INFO: total time: {}μs\n", duration.count());
         }
         SECTION("Test BitShift kernels with Broadcasting") {
             std::size_t number_of_operation = 0;
@@ -194,7 +199,7 @@ TEST_CASE("[cpu/operator] BitShift_TEST", "[BitShift][CPU]") {
                                 }
                                 else
                                 {
-                                    result[idx_out + d] = array0[idx0] >> array1[idx1];                               
+                                    result[idx_out + d] = array0[idx0] >> array1[idx1];
                                 }
                             }
                         }
@@ -222,12 +227,7 @@ TEST_CASE("[cpu/operator] BitShift_TEST", "[BitShift][CPU]") {
                 duration += std::chrono::duration_cast<std::chrono::microseconds>(end - start);
 
                 // comparison between truth and computed result
-                bool equiv = (approxEq<int>(*(op->getOutput(0)), *Tres));
-                if(equiv == false)
-                {
-                    std::cout << "Problem\n";
-                }
-                REQUIRE(equiv);
+                REQUIRE(approxEq<int>(*(op->getOutput(0)), *Tres));
 
                 delete[] array0;
                 delete[] array1;
@@ -236,8 +236,8 @@ TEST_CASE("[cpu/operator] BitShift_TEST", "[BitShift][CPU]") {
                 const std::size_t nb_elements = std::accumulate(dimsOut.cbegin(), dimsOut.cend(), std::size_t(1), std::multiplies<std::size_t>());
                 number_of_operation += nb_elements;
             }
-            std::cout << "number of elements over time spent: " << (number_of_operation / duration.count())<< std::endl;
-            std::cout << "total time: " << duration.count() << "μs" << std::endl;
+            fmt::print("INFO: number of elements over time spent: {}\n", (number_of_operation / duration.count()));
+            fmt::print("INFO: total time: {}μs\n", duration.count());
         }
 
 }
diff --git a/unit_tests/operator/Test_ClipImpl.cpp b/unit_tests/operator/Test_ClipImpl.cpp
index 45c8da5bf7ecc84fad6b3e694fe204540f579af3..1a7aa5e548a4e6b93c0052758fb9210fd8b14818 100644
--- a/unit_tests/operator/Test_ClipImpl.cpp
+++ b/unit_tests/operator/Test_ClipImpl.cpp
@@ -9,36 +9,37 @@
  *
  ********************************************************************************/
 
-#include <catch2/catch_test_macros.hpp>
+#include <algorithm>  // std::max, std::min
+#include <chrono>
 #include <cstddef>  // std::size_t
 #include <cstdint>  // std::uint16_t
-#include <chrono>
-#include <iostream>
-#include <vector>
-#include <algorithm>
-#include <iomanip>
 #include <memory>
-#include <random>   // std::random_device, std::mt19937, std::uniform_real_distribution
+#include <random>      // std::random_device, std::mt19937
+                       // std::uniform_int_distribution, std::uniform_real_distribution
+#include <vector>
+
+#include <catch2/catch_test_macros.hpp>
+#include <fmt/core.h>
 
+#include "aidge/backend/cpu/operator/ClipImpl.hpp"
 #include "aidge/data/Tensor.hpp"
 #include "aidge/operator/Clip.hpp"
 #include "aidge/operator/OperatorTensor.hpp"
 #include "aidge/utils/TensorUtils.hpp"
-#include "aidge/backend/cpu.hpp"
 
 void ComputeClipBackward(const std::vector<float>& vec1, std::vector<float>& vec2, float min, float max) {
     if (vec1.size() != vec2.size()) {
-        std::cerr << "Vectors should have the same sizes." << std::endl;
+        fmt::print(stderr, "Vectors should have the same sizes.\n");
         return;
     }
 
-    for (size_t i = 0; i < vec1.size(); ++i) {
+    for (std::size_t i = 0; i < vec1.size(); ++i) {
         if (vec1[i] < min || vec1[i] > max) {
             vec2[i] = 0.0f;
         }
     }
 }
-namespace Aidge 
+namespace Aidge
 {
 TEST_CASE("[cpu/operator] Clip", "[Clip][CPU]")
  {
@@ -47,8 +48,8 @@ TEST_CASE("[cpu/operator] Clip", "[Clip][CPU]")
     std::random_device rd;
     std::mt19937 gen(rd());
     std::uniform_real_distribution<float> dis(0.0, 10.0);
-    std::uniform_real_distribution<float> dismin(0.0, 4.5); 
-    std::uniform_real_distribution<float> dismax(5.5, 10.0); 
+    std::uniform_real_distribution<float> dismin(0.0, 4.5);
+    std::uniform_real_distribution<float> dismax(5.5, 10.0);
     std::uniform_int_distribution<std::size_t> distDims(5,15);
     std::uniform_int_distribution<std::size_t> distNbMatrix(1, 5);
 
@@ -71,7 +72,7 @@ TEST_CASE("[cpu/operator] Clip", "[Clip][CPU]")
 
             // Create and populate the array with random float values
             float* Array = new float[dim0*dim1];
-            for (int i = 0; i < dim0*dim1; ++i) {
+            for (std::size_t i = 0; i < dim0*dim1; ++i) {
                 Array[i] = dis(gen); // Generate random float value
             }
 
@@ -80,7 +81,7 @@ TEST_CASE("[cpu/operator] Clip", "[Clip][CPU]")
             TInput -> resize({dim0,dim1});
             TInput -> setBackend("cpu");
             TInput -> getImpl() -> setRawPtr(Array, dim0*dim1);
-            
+
             float min = dismin(gen);
             std::shared_ptr<Tensor> Tmin = std::make_shared<Tensor>(DataType::Float32);
             Tmin -> resize({});
@@ -109,7 +110,7 @@ TEST_CASE("[cpu/operator] Clip", "[Clip][CPU]")
             op->setDataType(DataType::Float32);
             op->setBackend("cpu");
             op->forwardDims(true);
-            
+
             start = std::chrono::system_clock::now();
             myClip->forward();
             end = std::chrono::system_clock::now();
@@ -118,9 +119,9 @@ TEST_CASE("[cpu/operator] Clip", "[Clip][CPU]")
 
             REQUIRE(approxEq<float>(*(op->getOutput(0)), *Tres));
         }
-        std::cout << "multiplications over time spent: " << totalComputation/duration.count() << std::endl;
-        std::cout << "total time: " << duration.count() << std::endl;
-    } 
+        fmt::print("INFO: multiplications over time spent: {}\n", totalComputation/duration.count());
+        fmt::print("INFO: total time: {}\n", duration.count());
+    }
     SECTION("Clip test with min >= max [Forward]") {
         std::size_t totalComputation = 0;
         for (std::uint16_t trial = 0; trial < NBTRIALS; ++trial) {
@@ -131,7 +132,7 @@ TEST_CASE("[cpu/operator] Clip", "[Clip][CPU]")
 
             // Create and populate the array with random float values
             float* Array = new float[dim0*dim1];
-            for (int i = 0; i < dim0*dim1; ++i) {
+            for (std::size_t i = 0; i < dim0*dim1; ++i) {
                 Array[i] = dis(gen); // Generate random float value
             }
 
@@ -140,7 +141,7 @@ TEST_CASE("[cpu/operator] Clip", "[Clip][CPU]")
             TInput -> resize({dim0,dim1});
             TInput -> setBackend("cpu");
             TInput -> getImpl() -> setRawPtr(Array, dim0*dim1);
-            
+
             float min = dismax(gen);
             std::shared_ptr<Tensor> Tmin = std::make_shared<Tensor>(DataType::Float32);
             Tmin -> resize({});
@@ -169,7 +170,7 @@ TEST_CASE("[cpu/operator] Clip", "[Clip][CPU]")
             op->setDataType(DataType::Float32);
             op->setBackend("cpu");
             op->forwardDims(true);
-            
+
             start = std::chrono::system_clock::now();
             myClip->forward();
             end = std::chrono::system_clock::now();
@@ -178,13 +179,13 @@ TEST_CASE("[cpu/operator] Clip", "[Clip][CPU]")
 
             REQUIRE(approxEq<float>(*(op->getOutput(0)), *Tres));
         }
-        std::cout << "multiplications over time spent: " << totalComputation/duration.count() << std::endl;
-        std::cout << "total time: " << duration.count() << std::endl;
-    } 
+        fmt::print("INFO: multiplications over time spent: {}\n", totalComputation/duration.count());
+        fmt::print("INFO: total time: {}\n", duration.count());
+    }
     SECTION("Clip with Clip Attr [Forward]")
     {
         std::size_t totalComputation = 0;
-        for (std::uint16_t trial = 0; trial < NBTRIALS; ++trial) 
+        for (std::uint16_t trial = 0; trial < NBTRIALS; ++trial)
         {
 
             float min = dismin(gen);
@@ -200,7 +201,7 @@ TEST_CASE("[cpu/operator] Clip", "[Clip][CPU]")
 
             // Create and populate the array with random float values
             float* Array = new float[dim0*dim1];
-            for (int i = 0; i < dim0*dim1; ++i) {
+            for (std::size_t i = 0; i < dim0*dim1; ++i) {
                 Array[i] = dis(gen); // Generate random float value
             }
             // Convert Input to Tensor
@@ -231,8 +232,8 @@ TEST_CASE("[cpu/operator] Clip", "[Clip][CPU]")
 
             REQUIRE(approxEq<float>(*(op->getOutput(0)), *Tres));
         }
-        std::cout << "multiplications over time spent: " << totalComputation/duration.count() << std::endl;
-        std::cout << "total time: " << duration.count() << std::endl;
+        fmt::print("INFO: multiplications over time spent: {}\n", totalComputation/duration.count());
+        fmt::print("INFO: total time: {}\n", duration.count());
     }
     SECTION("Simple clip test [Backward]") {
         std::size_t totalComputation = 0;
@@ -243,13 +244,13 @@ TEST_CASE("[cpu/operator] Clip", "[Clip][CPU]")
             // generate Tensors dimensions
             const std::size_t dim0 = distDims(gen);
             const std::size_t dim1 = distDims(gen);
-  
+
             totalComputation += dim0*dim1;
 
             // Create and populate the array with random float values
             float* Array = new float[dim0*dim1];
             float* gradArray = new float[dim0*dim1];
-            for (int i = 0; i < dim0*dim1; ++i) {
+            for (std::size_t i = 0; i < dim0*dim1; ++i) {
                 Array[i] = dis(gen); // Generate random float value
                 gradArray[i] = dis(gen);
             }
@@ -264,7 +265,7 @@ TEST_CASE("[cpu/operator] Clip", "[Clip][CPU]")
             TInput -> resize({dim0,dim1});
             TInput -> setBackend("cpu");
             TInput -> getImpl() -> setRawPtr(Array, dim0*dim1);
-            
+
             float min = dismin(gen);
             std::shared_ptr<Tensor> Tmin = std::make_shared<Tensor>(DataType::Float32);
             Tmin -> resize({});
@@ -296,7 +297,7 @@ TEST_CASE("[cpu/operator] Clip", "[Clip][CPU]")
             myClip->forward();
 
             op->getOutput(0)->setGrad(TGrad);
-            
+
             start = std::chrono::system_clock::now();
             REQUIRE_NOTHROW(myClip->backward());
             end = std::chrono::system_clock::now();
@@ -310,9 +311,9 @@ TEST_CASE("[cpu/operator] Clip", "[Clip][CPU]")
             duration += std::chrono::duration_cast<std::chrono::microseconds>(end - start);
             REQUIRE(GT1 == BackwardTensorVec);
         }
-        std::cout << "multiplications over time spent: " << totalComputation/duration.count() << std::endl;
-        std::cout << "total time: " << duration.count() << std::endl;
+        fmt::print("INFO: multiplications over time spent: {}\n", totalComputation/duration.count());
+        fmt::print("INFO: total time: {}\n", duration.count());
     }
  }
-} // namespace Aidge 
+} // namespace Aidge
 }
\ No newline at end of file
diff --git a/unit_tests/operator/Test_GlobalAveragePoolingImpl.cpp b/unit_tests/operator/Test_GlobalAveragePoolingImpl.cpp
index 43af544871ad6c2ac319de09f3c6fce5065e60d5..63f8d3269cdb25a6d84c3e936d8f124b0964962d 100644
--- a/unit_tests/operator/Test_GlobalAveragePoolingImpl.cpp
+++ b/unit_tests/operator/Test_GlobalAveragePoolingImpl.cpp
@@ -9,34 +9,29 @@
  *
  ********************************************************************************/
 
-#include <aidge/utils/Types.h>
-#include <catch2/catch_test_macros.hpp>
 #include <chrono>
-#include <cmath>
 #include <cstddef> // std::size_t
 #include <cstdint> // std::uint16_t
-#include <iostream>
+#include <functional>  // std::multiplies
 #include <memory>
 #include <numeric> // std::accumulate
-#include <ostream>
-#include <random> // std::random_device, std::mt19937, std::uniform_real_distribution
+#include <random>      // std::random_device, std::mt19937
+                       // std::uniform_int_distribution, std::uniform_real_distribution
+#include <vector>
+
+#include <catch2/catch_test_macros.hpp>
+#include <fmt/core.h>
 
+#include "aidge/backend/cpu/data/TensorImpl.hpp"
+#include "aidge/backend/cpu/operator/GlobalAveragePoolingImpl.hpp"
+#include "aidge/data/Data.hpp"
 #include "aidge/data/Tensor.hpp"
 #include "aidge/operator/GlobalAveragePooling.hpp"
 #include "aidge/utils/TensorUtils.hpp"
-
-// debug print function
-void print_tensor(Aidge::Tensor &T) {
-  // Print tensors
-  std::cout << "Tensor : size =  [";
-  for (auto &dim : T.dims()) {
-    std::cout << dim << " , ";
-  }
-  std::cout << "]" << std::endl;
-  T.print();
-}
+#include "aidge/utils/Types.h"
 
 namespace Aidge {
+
 TEST_CASE("[cpu/operator] GlobalAveragePooling",
           "[GlobalAveragePooling][CPU]") {
   constexpr std::uint16_t NBTRIALS = 10;
@@ -54,9 +49,7 @@ TEST_CASE("[cpu/operator] GlobalAveragePooling",
                                                             std::size_t(7));
 
   // Create MatGlobalAveragePooling Operator
-  std::shared_ptr<Node> globAvgPool = GlobalAveragePooling();
-  auto op =
-      std::static_pointer_cast<OperatorTensor>(globAvgPool->getOperator());
+  std::shared_ptr<GlobalAveragePooling_Op> op = std::make_shared<GlobalAveragePooling_Op>();
   op->setDataType(DataType::Float32);
   op->setBackend("cpu");
 
@@ -99,7 +92,7 @@ TEST_CASE("[cpu/operator] GlobalAveragePooling",
       T0->resize(dims);
       T0->getImpl()->setRawPtr(array0, nb_elements);
 
-      REQUIRE_THROWS(globAvgPool->forward());
+      REQUIRE_THROWS(op->forward());
       delete[] array0;
     }
 
@@ -158,7 +151,7 @@ TEST_CASE("[cpu/operator] GlobalAveragePooling",
 
         op->forwardDims();
         start = std::chrono::system_clock::now();
-        REQUIRE_NOTHROW(globAvgPool->forward());
+        REQUIRE_NOTHROW(op->forward());
         end = std::chrono::system_clock::now();
         duration +=
             std::chrono::duration_cast<std::chrono::microseconds>(end - start);
@@ -231,7 +224,7 @@ TEST_CASE("[cpu/operator] GlobalAveragePooling",
 
           op->forwardDims();
           start = std::chrono::system_clock::now();
-          REQUIRE_NOTHROW(globAvgPool->forward());
+          REQUIRE_NOTHROW(op->forward());
           end = std::chrono::system_clock::now();
           duration += std::chrono::duration_cast<std::chrono::microseconds>(
               end - start);
@@ -358,7 +351,7 @@ TEST_CASE("[cpu/operator] GlobalAveragePooling",
           Tres->getImpl()->setRawPtr(result, out_nb_elems);
           op->forwardDims();
           start = std::chrono::system_clock::now();
-          REQUIRE_NOTHROW(globAvgPool->forward());
+          REQUIRE_NOTHROW(op->forward());
           end = std::chrono::system_clock::now();
           duration += std::chrono::duration_cast<std::chrono::microseconds>(
               end - start);
@@ -547,7 +540,7 @@ TEST_CASE("[cpu/operator] GlobalAveragePooling",
           Tres->getImpl()->setRawPtr(result, out_nb_elems);
           op->forwardDims();
           start = std::chrono::system_clock::now();
-          REQUIRE_NOTHROW(globAvgPool->forward());
+          REQUIRE_NOTHROW(op->forward());
           end = std::chrono::system_clock::now();
           duration += std::chrono::duration_cast<std::chrono::microseconds>(
               end - start);
@@ -561,12 +554,9 @@ TEST_CASE("[cpu/operator] GlobalAveragePooling",
           delete[] result;
         }
       }
-      std::cout << "GlobalAveragePooling total execution time : "
-                << duration.count() << "µs" << std::endl;
-      std::cout << "Number of operations : " << number_of_operation
-                << std::endl;
-      std::cout << "Operation / µs = " << number_of_operation / duration.count()
-                << std::endl;
+      fmt::print("INFO: GlobalAveragePooling total execution time: {}µs\n", duration.count());
+      fmt::print("INFO: Number of operations : {}\n", number_of_operation);
+      fmt::print("INFO: Operation / µs = {}\n", number_of_operation / duration.count());
     }
   }
 }