diff --git a/src/backends/backendsCommon/test/OptimizeSubgraphViewTests.cpp b/src/backends/backendsCommon/test/OptimizeSubgraphViewTests.cpp
new file mode 100644
index 0000000..a6e8356
--- /dev/null
+++ b/src/backends/backendsCommon/test/OptimizeSubgraphViewTests.cpp
@@ -0,0 +1,1277 @@
+//
+// Copyright © 2017 Arm Ltd. All rights reserved.
+// SPDX-License-Identifier: MIT
+//
+
+#include "CommonTestUtils.hpp"
+#include "MockBackend.hpp"
+#include "MockBackendId.hpp"
+
+#include <Graph.hpp>
+#include <Network.hpp>
+
+#include <backendsCommon/BackendRegistry.hpp>
+
+#include <boost/test/unit_test.hpp>
+
+#include <unordered_map>
+
+using namespace armnn;
+
+namespace
+{
+
+// The expected number of layers, input and output slots in a subgraph after a test
+struct ExpectedSubgraphSize
+{
+    size_t m_NumInputSlots  = 0;
+    size_t m_NumOutputSlots = 0;
+    size_t m_NumLayers      = 0;
+};
+
+// Keep the layers organized by layer name
+using LayerNameToLayerMap = std::unordered_map<std::string, Layer*>;
+
+// Used to convert input and output slots from reference type (as stored in graphs) to
+// pointer type (as stored in subgraphs)
+template <typename SlotType>
+SlotType* ConvertReferenceTypeToPointerType(const SlotType& input)
+{
+    return const_cast<SlotType*>(&input);
+}
+
+// Used to convert input and output slots from reference type (as stored in graphs) to
+// pointer type (as stored in subgraphs), array version
+template <typename SlotType>
+std::vector<SlotType*> ConvertReferenceTypeToPointerType(const std::vector<SlotType>& input)
+{
+    std::vector<SlotType*> output;
+    std::transform(input.begin(),
+                   input.end(),
+                   std::back_inserter(output),
+                   [](const SlotType& inputItem)
+    {
+        return ConvertReferenceTypeToPointerType(inputItem);
+    });
+
+    return output;
+}
+
+// Convenience function to add an input layer to a graph
+Layer* AddInputLayer(Graph& graph,
+                     const std::string& layerName,
+                     const TensorInfo& inputInfo,
+                     LayerBindingId inputId = 0)
+{
+    Layer* const inputLayer = graph.AddLayer<InputLayer>(inputId, layerName.c_str());
+    BOOST_TEST(inputLayer);
+    inputLayer->GetOutputSlot(0).SetTensorInfo(inputInfo);
+    return inputLayer;
+}
+
+// Convenience function to add an output layer to a graph
+Layer* AddOutputLayer(Graph& graph,
+                      const std::string& layerName)
+{
+    Layer* const outputLayer = graph.AddLayer<OutputLayer>(0, layerName.c_str());
+    BOOST_TEST(outputLayer);
+    return outputLayer;
+}
+
+// Convenience function to add a convolution layer to a graph
+Convolution2dLayer* AddConvolutionLayer(Graph& graph,
+                                        LayerNameToLayerMap& layersInGraph,
+                                        const Convolution2dDescriptor& convolutionDescriptor,
+                                        const std::string& layerName,
+                                        const TensorInfo& weightInfo,
+                                        const TensorInfo& biasInfo,
+                                        const TensorInfo& outputInfo)
+{
+    Convolution2dLayer* const convLayer = graph.AddLayer<Convolution2dLayer>(convolutionDescriptor, layerName.c_str());
+    BOOST_TEST(convLayer);
+    SetWeightAndBias(convLayer, weightInfo, biasInfo);
+    convLayer->GetOutputSlot(0).SetTensorInfo(outputInfo);
+    layersInGraph.insert(std::make_pair(convLayer->GetName(), convLayer));
+    return convLayer;
+}
+
+// Convenience function to add a pooling layer to a graph
+Pooling2dLayer* AddPoolingLayer(Graph& graph,
+                                LayerNameToLayerMap& layersInGraph,
+                                const Pooling2dDescriptor& poolingDescriptor,
+                                const std::string& layerName,
+                                const TensorInfo& outputInfo)
+{
+    Pooling2dLayer* const poolingLayer = graph.AddLayer<Pooling2dLayer>(poolingDescriptor, layerName.c_str());
+    BOOST_TEST(poolingLayer);
+    poolingLayer->GetOutputSlot(0).SetTensorInfo(outputInfo);
+    layersInGraph.insert(std::make_pair(poolingLayer->GetName(), poolingLayer));
+    return poolingLayer;
+}
+
+// Convenience function to add an addition layer to a graph
+AdditionLayer* AddAdditionaLayer(Graph& graph,
+                                 LayerNameToLayerMap& layersInGraph,
+                                 const std::string& layerName,
+                                 const TensorInfo& outputInfo)
+{
+    AdditionLayer* const additionLayer = graph.AddLayer<AdditionLayer>(layerName.c_str());
+    BOOST_TEST(additionLayer);
+    additionLayer->GetOutputSlot(0).SetTensorInfo(outputInfo);
+    layersInGraph.insert(std::make_pair(additionLayer->GetName(), additionLayer));
+    return additionLayer;
+}
+
+// Convenience function to check that the given substitution matches the specified expected values
+void CheckSubstitution(const OptimizationViews::SubstitutionPair& substitution,
+                       const ExpectedSubgraphSize& expectedSubstitutableSubgraphSize,
+                       const ExpectedSubgraphSize& expectedReplacementSubgraphSize,
+                       const SubgraphView::InputSlots& expectedSubstitutableInputSlots,
+                       const SubgraphView::OutputSlots& expectedSubstitutableOutputSlots,
+                       const SubgraphView::Layers& expectedSubstitutableLayers)
+{
+    const SubgraphView&              substitutableSubgraph            = substitution.m_SubstitutableSubgraph;
+    const SubgraphView::InputSlots&  substitutableSubgraphInputSlots  = substitutableSubgraph.GetInputSlots();
+    const SubgraphView::OutputSlots& substitutableSubgraphOutputSlots = substitutableSubgraph.GetOutputSlots();
+    const SubgraphView::Layers&      substitutableSubgraphLayers      = substitutableSubgraph.GetLayers();
+
+    const SubgraphView&              replacementSubgraph            = substitution.m_ReplacementSubgraph;
+    const SubgraphView::InputSlots&  replacementSubgraphInputSlots  = replacementSubgraph.GetInputSlots();
+    const SubgraphView::OutputSlots& replacementSubgraphOutputSlots = replacementSubgraph.GetOutputSlots();
+    const SubgraphView::Layers&      replacementSubgraphLayers      = replacementSubgraph.GetLayers();
+
+    BOOST_TEST(substitutableSubgraphInputSlots.size()  == expectedSubstitutableSubgraphSize.m_NumInputSlots);
+    BOOST_TEST(substitutableSubgraphOutputSlots.size() == expectedSubstitutableSubgraphSize.m_NumOutputSlots);
+    BOOST_TEST(substitutableSubgraphLayers.size()      == expectedSubstitutableSubgraphSize.m_NumLayers);
+
+    BOOST_TEST(AreEqual(substitutableSubgraphInputSlots,  expectedSubstitutableInputSlots));
+    BOOST_TEST(AreEqual(substitutableSubgraphOutputSlots, expectedSubstitutableOutputSlots));
+    BOOST_TEST(AreEqual(substitutableSubgraphLayers,      expectedSubstitutableLayers));
+
+    BOOST_TEST(replacementSubgraphInputSlots.size()  == expectedReplacementSubgraphSize.m_NumInputSlots);
+    BOOST_TEST(replacementSubgraphOutputSlots.size() == expectedReplacementSubgraphSize.m_NumOutputSlots);
+    BOOST_TEST(replacementSubgraphLayers.size()      == expectedReplacementSubgraphSize.m_NumLayers);
+
+    BOOST_TEST(!AreEqual(replacementSubgraphInputSlots,  expectedSubstitutableInputSlots));
+    BOOST_TEST(!AreEqual(replacementSubgraphOutputSlots, expectedSubstitutableOutputSlots));
+    BOOST_TEST(!AreEqual(replacementSubgraphLayers,      expectedSubstitutableLayers));
+
+    BOOST_TEST(std::all_of(replacementSubgraphLayers.begin(),
+                           replacementSubgraphLayers.end(),
+                           [](const Layer* layer)
+    {
+        return layer->GetType() == LayerType::PreCompiled;
+    }));
+}
+
+// Convenience function to check that the given failed subgraph matches the specified expected values
+void CheckFailedSubgraph(const SubgraphView& failedSubgraph,
+                         const ExpectedSubgraphSize& expectedFailedSubgraphSize,
+                         const SubgraphView::InputSlots& expectedFailedInputSlots,
+                         const SubgraphView::OutputSlots& expectedFailedOutputSlots,
+                         const SubgraphView::Layers& expectedFailedLayers)
+{
+    const SubgraphView::InputSlots&  failedSubgraphInputSlots  = failedSubgraph.GetInputSlots();
+    const SubgraphView::OutputSlots& failedSubgraphOutputSlots = failedSubgraph.GetOutputSlots();
+    const SubgraphView::Layers&      failedSubgraphLayers      = failedSubgraph.GetLayers();
+
+    BOOST_TEST(failedSubgraphInputSlots.size()  == expectedFailedSubgraphSize.m_NumInputSlots);
+    BOOST_TEST(failedSubgraphOutputSlots.size() == expectedFailedSubgraphSize.m_NumOutputSlots);
+    BOOST_TEST(failedSubgraphLayers.size()      == expectedFailedSubgraphSize.m_NumLayers);
+
+    BOOST_TEST(AreEqual(failedSubgraphInputSlots,  expectedFailedInputSlots));
+    BOOST_TEST(AreEqual(failedSubgraphOutputSlots, expectedFailedOutputSlots));
+    BOOST_TEST(AreEqual(failedSubgraphLayers,      expectedFailedLayers));
+}
+
+// Convenience function to check that the given untouched subgraph matches the specified expected values
+void CheckUntouchedSubgraph(const SubgraphView& untouchedSubgraph,
+                            const ExpectedSubgraphSize& expectedUntouchedSubgraphSize,
+                            const SubgraphView::InputSlots& expectedUntouchedInputSlots,
+                            const SubgraphView::OutputSlots& expectedUntouchedOutputSlots,
+                            const SubgraphView::Layers& expectedUntouchedLayers)
+{
+    const SubgraphView::InputSlots&  untouchedSubgraphInputSlots  = untouchedSubgraph.GetInputSlots();
+    const SubgraphView::OutputSlots& untouchedSubgraphOutputSlots = untouchedSubgraph.GetOutputSlots();
+    const SubgraphView::Layers&      untouchedSubgraphLayers      = untouchedSubgraph.GetLayers();
+
+    BOOST_TEST(untouchedSubgraphInputSlots.size()  == expectedUntouchedSubgraphSize.m_NumInputSlots);
+    BOOST_TEST(untouchedSubgraphOutputSlots.size() == expectedUntouchedSubgraphSize.m_NumOutputSlots);
+    BOOST_TEST(untouchedSubgraphLayers.size()      == expectedUntouchedSubgraphSize.m_NumLayers);
+
+    BOOST_TEST(AreEqual(untouchedSubgraphInputSlots,  expectedUntouchedInputSlots));
+    BOOST_TEST(AreEqual(untouchedSubgraphOutputSlots, expectedUntouchedOutputSlots));
+    BOOST_TEST(AreEqual(untouchedSubgraphLayers,      expectedUntouchedLayers));
+}
+
+// Creates a subgraph containing only a single unsupported layer (only convolutions are unsupported by the mock backend)
+SubgraphView::SubgraphViewPtr BuildFullyUnsupportedSubgraph1(Graph& graph, LayerNameToLayerMap& layersInGraph)
+{
+    const TensorInfo inputInfo ({  1, 16, 16, 16 }, DataType::QuantisedAsymm8, 1.0f, 0);
+    const TensorInfo outputInfo({  1, 16, 16, 16 }, DataType::QuantisedAsymm8, 1.0f, 0);
+
+    Pooling2dDescriptor poolingDescriptor;
+    poolingDescriptor.m_PoolType      = armnn::PoolingAlgorithm::Average;
+    poolingDescriptor.m_PoolWidth     = 2;
+    poolingDescriptor.m_PoolHeight    = 2;
+    poolingDescriptor.m_StrideX       = 2;
+    poolingDescriptor.m_StrideY       = 2;
+    poolingDescriptor.m_PadLeft       = 1;
+    poolingDescriptor.m_PadRight      = 1;
+    poolingDescriptor.m_PadTop        = 1;
+    poolingDescriptor.m_PadBottom     = 1;
+    poolingDescriptor.m_PaddingMethod = armnn::PaddingMethod::Exclude;
+    poolingDescriptor.m_DataLayout    = DataLayout::NHWC;
+
+    // Construct the graph
+    Layer* const inputLayer = AddInputLayer(graph, "input layer", inputInfo);
+    Pooling2dLayer* const poolingLayer = AddPoolingLayer(graph, layersInGraph, poolingDescriptor,
+                                                         "pooling layer", outputInfo);
+    Layer* const outputLayer = AddOutputLayer(graph, "output layer");
+
+    // Connect the network
+    inputLayer->GetOutputSlot(0).Connect(poolingLayer->GetInputSlot(0));
+    poolingLayer->GetOutputSlot(0).Connect(outputLayer->GetInputSlot(0));
+
+    // Create the subgraph view for the whole network
+    return CreateSubgraphViewFrom(CreateInputsFrom({poolingLayer}),
+                                  CreateOutputsFrom({poolingLayer}),
+                                  {poolingLayer});
+}
+
+// Creates a subgraph containing only unsupported layers (only convolutions are unsupported by the mock backend)
+SubgraphView::SubgraphViewPtr BuildFullyUnsupportedSubgraph2(Graph& graph, LayerNameToLayerMap& layersInGraph)
+{
+    const TensorInfo inputInfo ({  1, 16, 16, 16 }, DataType::QuantisedAsymm8, 1.0f, 0);
+    const TensorInfo outputInfo({  1, 16, 16, 16 }, DataType::QuantisedAsymm8, 1.0f, 0);
+
+    Pooling2dDescriptor poolingDescriptor;
+    poolingDescriptor.m_PoolType      = armnn::PoolingAlgorithm::Average;
+    poolingDescriptor.m_PoolWidth     = 2;
+    poolingDescriptor.m_PoolHeight    = 2;
+    poolingDescriptor.m_StrideX       = 2;
+    poolingDescriptor.m_StrideY       = 2;
+    poolingDescriptor.m_PadLeft       = 1;
+    poolingDescriptor.m_PadRight      = 1;
+    poolingDescriptor.m_PadTop        = 1;
+    poolingDescriptor.m_PadBottom     = 1;
+    poolingDescriptor.m_PaddingMethod = armnn::PaddingMethod::Exclude;
+    poolingDescriptor.m_DataLayout    = DataLayout::NHWC;
+
+    // Construct the graph
+    Layer* const inputLayer = AddInputLayer(graph, "input layer", inputInfo);
+    Pooling2dLayer* const pooling1Layer = AddPoolingLayer(graph, layersInGraph, poolingDescriptor,
+                                                          "pooling1 layer", outputInfo);
+    Pooling2dLayer* const pooling2Layer = AddPoolingLayer(graph, layersInGraph, poolingDescriptor,
+                                                          "pooling2 layer", outputInfo);
+    Pooling2dLayer* const pooling3Layer = AddPoolingLayer(graph, layersInGraph, poolingDescriptor,
+                                                          "pooling3 layer", outputInfo);
+    Layer* const outputLayer = AddOutputLayer(graph, "output layer");
+
+    // Connect the network
+    inputLayer->GetOutputSlot(0).Connect(pooling1Layer->GetInputSlot(0));
+    pooling1Layer->GetOutputSlot(0).Connect(pooling2Layer->GetInputSlot(0));
+    pooling2Layer->GetOutputSlot(0).Connect(pooling3Layer->GetInputSlot(0));
+    pooling3Layer->GetOutputSlot(0).Connect(outputLayer->GetInputSlot(0));
+
+    // Create the subgraph view for the whole network
+    return CreateSubgraphViewFrom(CreateInputsFrom({pooling1Layer}),
+                                  CreateOutputsFrom({pooling3Layer}),
+                                  {pooling1Layer,
+                                   pooling2Layer,
+                                   pooling3Layer});
+}
+
+// Creates a simple subgraph with only one convolution layer, supported by the mock backend
+SubgraphView::SubgraphViewPtr BuildFullyOptimizableSubgraph1(Graph& graph, LayerNameToLayerMap& layersInGraph)
+{
+    const TensorInfo inputInfo ({  1, 16, 16, 16 }, DataType::QuantisedAsymm8, 1.0f, 0);
+    const TensorInfo outputInfo({  1, 16, 16, 16 }, DataType::QuantisedAsymm8, 1.0f, 0);
+    const TensorInfo weightInfo({ 16,  1,  1, 16 }, DataType::QuantisedAsymm8, 0.9f, 0);
+    const TensorInfo biasInfo  ({  1,  1,  1, 16 }, DataType::Signed32,        0.9f, 0);
+
+    Convolution2dDescriptor convolutionDescriptor;
+    convolutionDescriptor.m_StrideX     = 1;
+    convolutionDescriptor.m_StrideY     = 1;
+    convolutionDescriptor.m_BiasEnabled = true;
+    convolutionDescriptor.m_DataLayout  = DataLayout::NHWC;
+
+    // Construct the graph
+    Layer* const inputLayer = AddInputLayer(graph, "input layer", inputInfo);
+    Convolution2dLayer* const convLayer = AddConvolutionLayer(graph, layersInGraph, convolutionDescriptor,
+                                                              "conv layer", weightInfo, biasInfo, outputInfo);
+    Layer* const outputLayer = AddOutputLayer(graph, "output layer");
+
+    // Connect the network
+    inputLayer->GetOutputSlot(0).Connect(convLayer->GetInputSlot(0));
+    convLayer->GetOutputSlot(0).Connect(outputLayer->GetInputSlot(0));
+
+    // Create the subgraph view for the whole network
+    return CreateSubgraphViewFrom(CreateInputsFrom({convLayer}),
+                                  CreateOutputsFrom({convLayer}),
+                                  {convLayer});
+}
+
+// Creates a subgraph with five convolutions layers, all supported by the mock backend
+SubgraphView::SubgraphViewPtr BuildFullyOptimizableSubgraph2(Graph& graph, LayerNameToLayerMap& layersInGraph)
+{
+    const TensorInfo inputInfo ({  1, 16, 16, 16 }, DataType::QuantisedAsymm8, 1.0f, 0);
+    const TensorInfo outputInfo({  1, 16, 16, 16 }, DataType::QuantisedAsymm8, 1.0f, 0);
+    const TensorInfo weightInfo({ 16,  1,  1, 16 }, DataType::QuantisedAsymm8, 0.9f, 0);
+    const TensorInfo biasInfo  ({  1,  1,  1, 16 }, DataType::Signed32,        0.9f, 0);
+
+    Convolution2dDescriptor convolutionDescriptor;
+    convolutionDescriptor.m_StrideX     = 1;
+    convolutionDescriptor.m_StrideY     = 1;
+    convolutionDescriptor.m_BiasEnabled = true;
+    convolutionDescriptor.m_DataLayout  = DataLayout::NHWC;
+
+    // Construct the graph
+    Layer* const inputLayer = AddInputLayer(graph, "input layer", inputInfo);
+    Convolution2dLayer* const conv1Layer = AddConvolutionLayer(graph, layersInGraph, convolutionDescriptor,
+                                                               "conv1 layer", weightInfo, biasInfo, outputInfo);
+    Convolution2dLayer* const conv2Layer = AddConvolutionLayer(graph, layersInGraph, convolutionDescriptor,
+                                                               "conv2 layer", weightInfo, biasInfo, outputInfo);
+    Convolution2dLayer* const conv3Layer = AddConvolutionLayer(graph, layersInGraph, convolutionDescriptor,
+                                                               "conv3 layer", weightInfo, biasInfo, outputInfo);
+    Convolution2dLayer* const conv4Layer = AddConvolutionLayer(graph, layersInGraph, convolutionDescriptor,
+                                                               "conv4 layer", weightInfo, biasInfo, outputInfo);
+    Convolution2dLayer* const conv5Layer = AddConvolutionLayer(graph, layersInGraph, convolutionDescriptor,
+                                                               "conv5 layer", weightInfo, biasInfo, outputInfo);
+    Layer* const outputLayer = AddOutputLayer(graph, "output layer");
+
+    // Connect the network
+    inputLayer->GetOutputSlot(0).Connect(conv1Layer->GetInputSlot(0));
+    conv1Layer->GetOutputSlot(0).Connect(conv2Layer->GetInputSlot(0));
+    conv2Layer->GetOutputSlot(0).Connect(conv3Layer->GetInputSlot(0));
+    conv3Layer->GetOutputSlot(0).Connect(conv4Layer->GetInputSlot(0));
+    conv4Layer->GetOutputSlot(0).Connect(conv5Layer->GetInputSlot(0));
+    conv5Layer->GetOutputSlot(0).Connect(outputLayer->GetInputSlot(0));
+
+    // Create the subgraph view for the whole network
+    return CreateSubgraphViewFrom(CreateInputsFrom({conv1Layer}),
+                                  CreateOutputsFrom({conv5Layer}),
+                                  {conv1Layer,
+                                   conv2Layer,
+                                   conv3Layer,
+                                   conv4Layer,
+                                   conv5Layer});
+}
+
+// Creates a subgraph with both supported and unsupported layers
+// (only convolutions are unsupported by the mock backend)
+SubgraphView::SubgraphViewPtr BuildPartiallySupportedSubgraph(Graph& graph, LayerNameToLayerMap& layersInGraph)
+{
+    const TensorInfo inputInfo ({  1, 16, 16, 16 }, DataType::QuantisedAsymm8, 1.0f, 0);
+    const TensorInfo outputInfo({  1, 16, 16, 16 }, DataType::QuantisedAsymm8, 1.0f, 0);
+    const TensorInfo weightInfo({ 16,  1,  1, 16 }, DataType::QuantisedAsymm8, 0.9f, 0);
+    const TensorInfo biasInfo  ({  1,  1,  1, 16 }, DataType::Signed32,        0.9f, 0);
+
+    Convolution2dDescriptor convolutionDescriptor;
+    convolutionDescriptor.m_StrideX     = 1;
+    convolutionDescriptor.m_StrideY     = 1;
+    convolutionDescriptor.m_BiasEnabled = true;
+    convolutionDescriptor.m_DataLayout  = DataLayout::NHWC;
+
+    Pooling2dDescriptor poolingDescriptor;
+    poolingDescriptor.m_PoolType      = armnn::PoolingAlgorithm::Average;
+    poolingDescriptor.m_PoolWidth     = 2;
+    poolingDescriptor.m_PoolHeight    = 2;
+    poolingDescriptor.m_StrideX       = 2;
+    poolingDescriptor.m_StrideY       = 2;
+    poolingDescriptor.m_PadLeft       = 1;
+    poolingDescriptor.m_PadRight      = 1;
+    poolingDescriptor.m_PadTop        = 1;
+    poolingDescriptor.m_PadBottom     = 1;
+    poolingDescriptor.m_PaddingMethod = armnn::PaddingMethod::Exclude;
+    poolingDescriptor.m_DataLayout    = DataLayout::NHWC;
+
+    // Construct the graph
+    Layer* const inputLayer = AddInputLayer(graph, "input layer", inputInfo);
+    Convolution2dLayer* const conv1Layer = AddConvolutionLayer(graph, layersInGraph, convolutionDescriptor,
+                                                               "conv1 layer", weightInfo, biasInfo, outputInfo);
+    Pooling2dLayer* const pooling1Layer = AddPoolingLayer(graph, layersInGraph, poolingDescriptor,
+                                                          "pooling1 layer", outputInfo);
+    Pooling2dLayer* const pooling2Layer = AddPoolingLayer(graph, layersInGraph, poolingDescriptor,
+                                                          "pooling2 layer", outputInfo);
+    Convolution2dLayer* const conv2Layer = AddConvolutionLayer(graph, layersInGraph, convolutionDescriptor,
+                                                               "conv2 layer", weightInfo, biasInfo, outputInfo);
+    Pooling2dLayer* const pooling3Layer = AddPoolingLayer(graph, layersInGraph, poolingDescriptor,
+                                                          "pooling3 layer", outputInfo);
+    Layer* const outputLayer = AddOutputLayer(graph, "output layer");
+
+    // Connect the network
+    inputLayer->GetOutputSlot(0).Connect(conv1Layer->GetInputSlot(0));
+    conv1Layer->GetOutputSlot(0).Connect(pooling1Layer->GetInputSlot(0));
+    pooling1Layer->GetOutputSlot(0).Connect(pooling2Layer->GetInputSlot(0));
+    pooling2Layer->GetOutputSlot(0).Connect(conv2Layer->GetInputSlot(0));
+    conv2Layer->GetOutputSlot(0).Connect(pooling3Layer->GetInputSlot(0));
+    pooling3Layer->GetOutputSlot(0).Connect(outputLayer->GetInputSlot(0));
+
+    // Create the subgraph view for the whole network
+    return CreateSubgraphViewFrom(CreateInputsFrom({conv1Layer}),
+                                  CreateOutputsFrom({pooling3Layer}),
+                                  {conv1Layer,
+                                   pooling1Layer,
+                                   pooling2Layer,
+                                   conv2Layer,
+                                   pooling3Layer});
+}
+
+// Creates a subgraph with only unoptimizable layers ("unoptimizable" is added to the layer's name)
+SubgraphView::SubgraphViewPtr BuildFullyUnoptimizableSubgraph1(Graph& graph, LayerNameToLayerMap& layersInGraph)
+{
+    const TensorInfo inputInfo ({  1, 16, 16, 16 }, DataType::QuantisedAsymm8, 1.0f, 0);
+    const TensorInfo outputInfo({  1, 16, 16, 16 }, DataType::QuantisedAsymm8, 1.0f, 0);
+    const TensorInfo weightInfo({ 16,  1,  1, 16 }, DataType::QuantisedAsymm8, 0.9f, 0);
+    const TensorInfo biasInfo  ({  1,  1,  1, 16 }, DataType::Signed32,        0.9f, 0);
+
+    Convolution2dDescriptor convolutionDescriptor;
+    convolutionDescriptor.m_StrideX     = 1;
+    convolutionDescriptor.m_StrideY     = 1;
+    convolutionDescriptor.m_BiasEnabled = true;
+    convolutionDescriptor.m_DataLayout  = DataLayout::NHWC;
+
+    // Construct the graph
+    Layer* const inputLayer = AddInputLayer(graph, "input layer", inputInfo);
+    Convolution2dLayer* const convLayer = AddConvolutionLayer(graph, layersInGraph, convolutionDescriptor,
+                                                               "conv layer unoptimizable", weightInfo, biasInfo,
+                                                               outputInfo);
+    Layer* const outputLayer = AddOutputLayer(graph, "output layer");
+
+    // Connect the network
+    inputLayer->GetOutputSlot(0).Connect(convLayer->GetInputSlot(0));
+    convLayer->GetOutputSlot(0).Connect(outputLayer->GetInputSlot(0));
+
+    // Create the subgraph view for the whole network
+    return CreateSubgraphViewFrom(CreateInputsFrom({convLayer}),
+                                  CreateOutputsFrom({convLayer}),
+                                  {convLayer});
+}
+
+// Creates a subgraph with some unoptimizable layers ("unoptimizable" is added to the layer's name)
+SubgraphView::SubgraphViewPtr BuildPartiallyOptimizableSubgraph1(Graph& graph, LayerNameToLayerMap& layersInGraph)
+{
+    const TensorInfo inputInfo ({  1, 16, 16, 16 }, DataType::QuantisedAsymm8, 1.0f, 0);
+    const TensorInfo outputInfo({  1, 16, 16, 16 }, DataType::QuantisedAsymm8, 1.0f, 0);
+    const TensorInfo weightInfo({ 16,  1,  1, 16 }, DataType::QuantisedAsymm8, 0.9f, 0);
+    const TensorInfo biasInfo  ({  1,  1,  1, 16 }, DataType::Signed32,        0.9f, 0);
+
+    Convolution2dDescriptor convolutionDescriptor;
+    convolutionDescriptor.m_StrideX     = 1;
+    convolutionDescriptor.m_StrideY     = 1;
+    convolutionDescriptor.m_BiasEnabled = true;
+    convolutionDescriptor.m_DataLayout  = DataLayout::NHWC;
+
+    // Construct the graph
+    Layer* const inputLayer = AddInputLayer(graph, "input layer", inputInfo);
+    Convolution2dLayer* const conv1Layer = AddConvolutionLayer(graph, layersInGraph, convolutionDescriptor,
+                                                               "conv1 layer", weightInfo, biasInfo, outputInfo);
+    Convolution2dLayer* const conv2Layer = AddConvolutionLayer(graph, layersInGraph, convolutionDescriptor,
+                                                               "conv2 layer unoptimizable", weightInfo, biasInfo,
+                                                               outputInfo);
+    Convolution2dLayer* const conv3Layer = AddConvolutionLayer(graph, layersInGraph, convolutionDescriptor,
+                                                               "conv3 layer", weightInfo, biasInfo, outputInfo);
+    Convolution2dLayer* const conv4Layer = AddConvolutionLayer(graph, layersInGraph, convolutionDescriptor,
+                                                               "conv4 layer unoptimizable", weightInfo, biasInfo,
+                                                               outputInfo);
+    Convolution2dLayer* const conv5Layer = AddConvolutionLayer(graph, layersInGraph, convolutionDescriptor,
+                                                               "conv5 layer", weightInfo, biasInfo, outputInfo);
+    Layer* const outputLayer = AddOutputLayer(graph, "output layer");
+
+    // Connect the network
+    inputLayer->GetOutputSlot(0).Connect(conv1Layer->GetInputSlot(0));
+    conv1Layer->GetOutputSlot(0).Connect(conv2Layer->GetInputSlot(0));
+    conv2Layer->GetOutputSlot(0).Connect(conv3Layer->GetInputSlot(0));
+    conv3Layer->GetOutputSlot(0).Connect(conv4Layer->GetInputSlot(0));
+    conv4Layer->GetOutputSlot(0).Connect(conv5Layer->GetInputSlot(0));
+    conv5Layer->GetOutputSlot(0).Connect(outputLayer->GetInputSlot(0));
+
+    // Create the subgraph view for the whole network
+    return CreateSubgraphViewFrom(CreateInputsFrom({conv1Layer}),
+                                  CreateOutputsFrom({conv5Layer}),
+                                  {conv1Layer,
+                                   conv2Layer,
+                                   conv3Layer,
+                                   conv4Layer,
+                                   conv5Layer});
+}
+
+// Creates a subgraph with some input unoptimizable layers ("unoptimizable" is added to the layer's name),
+// this is meant to test input slots coming from different layers
+SubgraphView::SubgraphViewPtr BuildPartiallyOptimizableSubgraph2(Graph& graph, LayerNameToLayerMap& layersInGraph)
+{
+    const TensorInfo inputInfo ({  1, 16, 16, 16 }, DataType::QuantisedAsymm8, 1.0f, 0);
+    const TensorInfo outputInfo({  1, 16, 16, 16 }, DataType::QuantisedAsymm8, 1.0f, 0);
+    const TensorInfo weightInfo({ 16,  1,  1, 16 }, DataType::QuantisedAsymm8, 0.9f, 0);
+    const TensorInfo biasInfo  ({  1,  1,  1, 16 }, DataType::Signed32,        0.9f, 0);
+
+    Convolution2dDescriptor convolutionDescriptor;
+    convolutionDescriptor.m_StrideX     = 1;
+    convolutionDescriptor.m_StrideY     = 1;
+    convolutionDescriptor.m_BiasEnabled = true;
+    convolutionDescriptor.m_DataLayout  = DataLayout::NHWC;
+
+    // Construct the graph
+    Layer* const input1Layer = AddInputLayer(graph, "input1 layer", inputInfo, 0);
+    Layer* const input2Layer = AddInputLayer(graph, "input2 layer", inputInfo, 1);
+    Convolution2dLayer* const conv1Layer = AddConvolutionLayer(graph, layersInGraph, convolutionDescriptor,
+                                                               "conv1 layer", weightInfo, biasInfo, outputInfo);
+    Convolution2dLayer* const conv2Layer = AddConvolutionLayer(graph, layersInGraph, convolutionDescriptor,
+                                                               "conv2 layer unoptimizable", weightInfo, biasInfo,
+                                                               outputInfo);
+    Convolution2dLayer* const conv3Layer = AddConvolutionLayer(graph, layersInGraph, convolutionDescriptor,
+                                                               "conv3 layer", weightInfo, biasInfo, outputInfo);
+    AdditionLayer* const addLayer = AddAdditionaLayer(graph, layersInGraph, "add layer", outputInfo);
+    Layer* const outputLayer = AddOutputLayer(graph, "output layer");
+
+    // Connect the network
+    input1Layer->GetOutputSlot(0).Connect(conv1Layer->GetInputSlot(0));
+    input2Layer->GetOutputSlot(0).Connect(conv2Layer->GetInputSlot(0));
+    conv1Layer->GetOutputSlot(0).Connect(addLayer->GetInputSlot(0));
+    conv2Layer->GetOutputSlot(0).Connect(conv3Layer->GetInputSlot(0));
+    conv3Layer->GetOutputSlot(0).Connect(addLayer->GetInputSlot(1));
+    addLayer->GetOutputSlot(0).Connect(outputLayer->GetInputSlot(0));
+
+    // Create the subgraph view for the whole network
+    return CreateSubgraphViewFrom(CreateInputsFrom({conv1Layer,
+                                                    conv2Layer}),
+                                  CreateOutputsFrom({addLayer}),
+                                  {conv1Layer,
+                                   conv2Layer,
+                                   conv3Layer,
+                                   addLayer});
+}
+
+// The input subgraph contains only a single unsupported layer (only convolutions are unsupported by the mock backend)
+void FullyUnsupporteSubgraphTestImpl1()
+{
+    Graph graph;
+    LayerNameToLayerMap layersInGraph;
+
+    // Create an unsupported subgraph
+    SubgraphView::SubgraphViewPtr subgraphPtr = BuildFullyUnsupportedSubgraph1(graph, layersInGraph);
+    BOOST_TEST((subgraphPtr != nullptr));
+
+    const SubgraphView::InputSlots&  subgraphInputSlots  = subgraphPtr->GetInputSlots();
+    const SubgraphView::OutputSlots& subgraphOutputSlots = subgraphPtr->GetOutputSlots();
+    const SubgraphView::Layers&      subgraphLayers      = subgraphPtr->GetLayers();
+
+    BOOST_TEST(subgraphInputSlots.size()  == 1);
+    BOOST_TEST(subgraphOutputSlots.size() == 1);
+    BOOST_TEST(subgraphLayers.size()      == 1);
+
+    BOOST_TEST(Contains(layersInGraph, "pooling layer"));
+
+    // Create a mock backend object
+    auto backendObjPtr = CreateBackendObject(MockBackendId());
+    BOOST_TEST((backendObjPtr != nullptr));
+
+    // Optimize the subgraph
+    OptimizationViews optimizationViews;
+
+    // Check that the optimization is carried out correctly, but no optimization is performed
+    BOOST_CHECK_NO_THROW(optimizationViews = backendObjPtr->OptimizeSubgraphView(*subgraphPtr));
+
+    // =======================================================================
+    // The expected results are:
+    //  - No substitutions
+    //  - Exactly one failed subgraph, corresponding to the whole original one
+    //  - No untouched subgraphs
+    // =======================================================================
+
+    // -----------------------
+    // Check the substitutions
+    // -----------------------
+
+    BOOST_TEST(optimizationViews.GetSubstitutions().empty());
+
+    // --------------------------
+    // Check the failed subgraphs
+    // --------------------------
+
+    const OptimizationViews::Subgraphs& failedSubgraphs = optimizationViews.GetFailedSubgraphs();
+    BOOST_TEST(failedSubgraphs.size() == 1);
+
+    CheckFailedSubgraph(failedSubgraphs.at(0),
+                        { subgraphInputSlots.size(), subgraphOutputSlots.size(), subgraphLayers.size() },
+                        subgraphInputSlots,
+                        subgraphOutputSlots,
+                        subgraphLayers);
+
+    // -----------------------------
+    // Check the untouched subgraphs
+    // -----------------------------
+
+    BOOST_TEST(optimizationViews.GetUntouchedSubgraphs().empty());
+}
+
+// The input subgraph contains only unsupported layers (only convolutions are unsupported by the mock backend)
+void FullyUnsupporteSubgraphTestImpl2()
+{
+    Graph graph;
+    LayerNameToLayerMap layersInGraph;
+
+    // Create an unsupported subgraph
+    SubgraphView::SubgraphViewPtr subgraphPtr = BuildFullyUnsupportedSubgraph2(graph, layersInGraph);
+    BOOST_TEST((subgraphPtr != nullptr));
+
+    const SubgraphView::InputSlots&  subgraphInputSlots  = subgraphPtr->GetInputSlots();
+    const SubgraphView::OutputSlots& subgraphOutputSlots = subgraphPtr->GetOutputSlots();
+    const SubgraphView::Layers&      subgraphLayers      = subgraphPtr->GetLayers();
+
+    BOOST_TEST(subgraphInputSlots.size()  == 1);
+    BOOST_TEST(subgraphOutputSlots.size() == 1);
+    BOOST_TEST(subgraphLayers.size()      == 3);
+
+    BOOST_TEST(Contains(layersInGraph, "pooling1 layer"));
+    BOOST_TEST(Contains(layersInGraph, "pooling2 layer"));
+    BOOST_TEST(Contains(layersInGraph, "pooling3 layer"));
+
+    // Create a mock backend object
+    auto backendObjPtr = CreateBackendObject(MockBackendId());
+    BOOST_TEST((backendObjPtr != nullptr));
+
+    // Optimize the subgraph
+    OptimizationViews optimizationViews;
+
+    // Check that the optimization is carried out correctly, but no optimization is performed
+    BOOST_CHECK_NO_THROW(optimizationViews = backendObjPtr->OptimizeSubgraphView(*subgraphPtr));
+
+    // =======================================================================
+    // The expected results are:
+    //  - No substitutions
+    //  - Exactly one failed subgraph, corresponding to the whole original one
+    //  - No untouched subgraphs
+    // =======================================================================
+
+    // -----------------------
+    // Check the substitutions
+    // -----------------------
+
+    BOOST_TEST(optimizationViews.GetSubstitutions().empty());
+
+    // --------------------------
+    // Check the failed subgraphs
+    // --------------------------
+
+    const OptimizationViews::Subgraphs& failedSubgraphs = optimizationViews.GetFailedSubgraphs();
+    BOOST_TEST(failedSubgraphs.size() == 1);
+
+    std::vector<Layer*> expectedFailedLayers{ layersInGraph.at("pooling1 layer"),
+                                              layersInGraph.at("pooling2 layer"),
+                                              layersInGraph.at("pooling3 layer") };
+
+    const SubgraphView& failedSubgraph = failedSubgraphs.at(0);
+
+    CheckFailedSubgraph(failedSubgraph,
+                        { subgraphInputSlots.size(), subgraphOutputSlots.size(), subgraphLayers.size() },
+                        subgraphInputSlots,
+                        subgraphOutputSlots,
+                        subgraphLayers);
+
+    const SubgraphView::Layers& failedSubgraphLayers = failedSubgraph.GetLayers();
+
+    BOOST_TEST(failedSubgraphLayers.front() + 0, expectedFailedLayers.at(0));
+    BOOST_TEST(failedSubgraphLayers.front() + 1, expectedFailedLayers.at(1));
+    BOOST_TEST(failedSubgraphLayers.front() + 2, expectedFailedLayers.at(2));
+
+    // -----------------------------
+    // Check the untouched subgraphs
+    // -----------------------------
+
+    BOOST_TEST(optimizationViews.GetUntouchedSubgraphs().empty());
+}
+
+// A simple case with only one layer (convolution) to optimize, supported by the mock backend
+void FullyOptimizableSubgraphTestImpl1()
+{
+    Graph graph;
+    LayerNameToLayerMap layersInGraph;
+
+    // Create a fully optimizable subgraph
+    SubgraphViewSelector::SubgraphViewPtr subgraphPtr = BuildFullyOptimizableSubgraph1(graph, layersInGraph);
+    BOOST_TEST((subgraphPtr != nullptr));
+
+    const SubgraphView::InputSlots&  subgraphInputSlots  = subgraphPtr->GetInputSlots();
+    const SubgraphView::OutputSlots& subgraphOutputSlots = subgraphPtr->GetOutputSlots();
+    const SubgraphView::Layers&      subgraphLayers      = subgraphPtr->GetLayers();
+
+    BOOST_TEST(subgraphInputSlots.size()  == 1);
+    BOOST_TEST(subgraphOutputSlots.size() == 1);
+    BOOST_TEST(subgraphLayers.size()      == 1);
+
+    BOOST_TEST(Contains(layersInGraph, "conv layer"));
+
+    // Create a mock backend object
+    auto backendObjPtr = CreateBackendObject(MockBackendId());
+    BOOST_TEST((backendObjPtr != nullptr));
+
+    // Optimize the subgraph
+    OptimizationViews optimizationViews;
+
+    // Check that the optimization is carried out correctly
+    BOOST_CHECK_NO_THROW(optimizationViews = backendObjPtr->OptimizeSubgraphView(*subgraphPtr));
+
+    // ===========================================================================================
+    // The expected results are:
+    //  - Exactly one substitution, mapping the whole input subgraph to a new replacement subgraph
+    //  - No failed subgraphs
+    //  - No untouched subgraphs
+    // ===========================================================================================
+
+    // -----------------------
+    // Check the substitutions
+    // -----------------------
+
+    const OptimizationViews::Substitutions& substitutions = optimizationViews.GetSubstitutions();
+    BOOST_TEST(substitutions.size() == 1);
+
+    CheckSubstitution(substitutions.at(0),
+                      { subgraphInputSlots.size(), subgraphOutputSlots.size(), subgraphLayers.size() },
+                      { subgraphInputSlots.size(), subgraphOutputSlots.size(), 1 },
+                      subgraphInputSlots,
+                      subgraphOutputSlots,
+                      subgraphLayers);
+
+    // --------------------------
+    // Check the failed subgraphs
+    // --------------------------
+
+    BOOST_TEST(optimizationViews.GetFailedSubgraphs().empty());
+
+    // -----------------------------
+    // Check the untouched subgraphs
+    // -----------------------------
+
+    BOOST_TEST(optimizationViews.GetUntouchedSubgraphs().empty());
+}
+
+// A case with five layers (all convolutions) to optimize, all supported by the mock backend
+void FullyOptimizableSubgraphTestImpl2()
+{
+    Graph graph;
+    LayerNameToLayerMap layersInGraph;
+
+    // Create a fully optimizable subgraph
+    SubgraphViewSelector::SubgraphViewPtr subgraphPtr = BuildFullyOptimizableSubgraph2(graph, layersInGraph);
+    BOOST_TEST((subgraphPtr != nullptr));
+
+    const SubgraphView::InputSlots&  subgraphInputSlots  = subgraphPtr->GetInputSlots();
+    const SubgraphView::OutputSlots& subgraphOutputSlots = subgraphPtr->GetOutputSlots();
+    const SubgraphView::Layers&      subgraphLayers      = subgraphPtr->GetLayers();
+
+    BOOST_TEST(subgraphPtr->GetInputSlots().size()  == 1);
+    BOOST_TEST(subgraphPtr->GetOutputSlots().size() == 1);
+    BOOST_TEST(subgraphPtr->GetLayers().size()      == 5);
+
+    BOOST_TEST(Contains(layersInGraph, "conv1 layer"));
+    BOOST_TEST(Contains(layersInGraph, "conv2 layer"));
+    BOOST_TEST(Contains(layersInGraph, "conv3 layer"));
+    BOOST_TEST(Contains(layersInGraph, "conv4 layer"));
+    BOOST_TEST(Contains(layersInGraph, "conv5 layer"));
+
+    // Create a mock backend object
+    auto backendObjPtr = CreateBackendObject(MockBackendId());
+    BOOST_TEST((backendObjPtr != nullptr));
+
+    // Optimize the subgraph
+    OptimizationViews optimizationViews;
+
+    // Check that the optimization is carried out correctly
+    BOOST_CHECK_NO_THROW(optimizationViews = backendObjPtr->OptimizeSubgraphView(*subgraphPtr));
+
+    // ===========================================================================================
+    // The expected results are:
+    //  - Exactly one substitution, mapping the whole input subgraph to a new replacement subgraph
+    //  - No failed subgraphs
+    //  - No untouched subgraphs
+    // ===========================================================================================
+
+    // -----------------------
+    // Check the substitutions
+    // -----------------------
+
+    const OptimizationViews::Substitutions& substitutions = optimizationViews.GetSubstitutions();
+    BOOST_TEST(substitutions.size() == 1);
+
+    std::list<Layer*> expectedSubstitutableLayers{ layersInGraph.at("conv1 layer"),
+                                                   layersInGraph.at("conv2 layer"),
+                                                   layersInGraph.at("conv3 layer"),
+                                                   layersInGraph.at("conv4 layer"),
+                                                   layersInGraph.at("conv5 layer") };
+
+    const OptimizationViews::SubstitutionPair& substitution = substitutions.at(0);
+
+    CheckSubstitution(substitution,
+                      { subgraphInputSlots.size(), subgraphOutputSlots.size(), subgraphLayers.size() },
+                      { subgraphInputSlots.size(), subgraphOutputSlots.size(), 1 },
+                      subgraphInputSlots,
+                      subgraphOutputSlots,
+                      expectedSubstitutableLayers);
+
+    const SubgraphView::Layers& substitutableSubgraphLayers = substitution.m_SubstitutableSubgraph.GetLayers();
+
+    BOOST_TEST(substitutableSubgraphLayers.front() + 0, expectedSubstitutableLayers.front() + 0);
+    BOOST_TEST(substitutableSubgraphLayers.front() + 1, expectedSubstitutableLayers.front() + 1);
+    BOOST_TEST(substitutableSubgraphLayers.front() + 2, expectedSubstitutableLayers.front() + 2);
+    BOOST_TEST(substitutableSubgraphLayers.front() + 3, expectedSubstitutableLayers.front() + 3);
+    BOOST_TEST(substitutableSubgraphLayers.front() + 4, expectedSubstitutableLayers.front() + 4);
+
+    // --------------------------
+    // Check the failed subgraphs
+    // --------------------------
+
+    BOOST_TEST(optimizationViews.GetFailedSubgraphs().empty());
+
+    // -----------------------------
+    // Check the untouched subgraphs
+    // -----------------------------
+
+    BOOST_TEST(optimizationViews.GetUntouchedSubgraphs().empty());
+}
+
+// The input subgraph contaions both supported and unsupported layers
+// (but only convolutions are unsupported by the mock backend)
+void PartiallySupportedSubgraphTestImpl()
+{
+    Graph graph;
+    LayerNameToLayerMap layersInGraph;
+
+    // Create a fully optimizable subgraph
+    SubgraphViewSelector::SubgraphViewPtr subgraphPtr = BuildPartiallySupportedSubgraph(graph, layersInGraph);
+    BOOST_TEST((subgraphPtr != nullptr));
+
+    const SubgraphView::InputSlots&  subgraphInputSlots  = subgraphPtr->GetInputSlots();
+    const SubgraphView::OutputSlots& subgraphOutputSlots = subgraphPtr->GetOutputSlots();
+    const SubgraphView::Layers&      subgraphLayers      = subgraphPtr->GetLayers();
+
+    BOOST_TEST(subgraphInputSlots.size()  == 1);
+    BOOST_TEST(subgraphOutputSlots.size() == 1);
+    BOOST_TEST(subgraphLayers.size()      == 5);
+
+    BOOST_TEST(Contains(layersInGraph, "conv1 layer"));
+    BOOST_TEST(Contains(layersInGraph, "pooling1 layer"));
+    BOOST_TEST(Contains(layersInGraph, "pooling2 layer"));
+    BOOST_TEST(Contains(layersInGraph, "conv2 layer"));
+    BOOST_TEST(Contains(layersInGraph, "pooling3 layer"));
+
+    // Create a mock backend object
+    auto backendObjPtr = CreateBackendObject(MockBackendId());
+    BOOST_TEST((backendObjPtr != nullptr));
+
+    // Optimize the subgraph
+    OptimizationViews optimizationViews;
+
+    // Check that the optimization is carried out correctly
+    BOOST_CHECK_NO_THROW(optimizationViews = backendObjPtr->OptimizeSubgraphView(*subgraphPtr));
+
+    // ========================================================================
+    // The expected results are:
+    //  - Exactly two substitution, corresponding to the supported layers
+    //  - Exactly two failed subgraphs, corresponding to the unsupported layers
+    //  - No untouched subgraphs
+    // ========================================================================
+
+    // -----------------------
+    // Check the substitutions
+    // -----------------------
+
+    const OptimizationViews::Substitutions& substitutions = optimizationViews.GetSubstitutions();
+    BOOST_TEST(substitutions.size() == 2);
+
+    std::vector<ExpectedSubgraphSize> expectedSubstitutableSubgraphSizes{ { 1, 1, 1 },
+                                                                          { 1, 1, 1 } };
+    std::vector<ExpectedSubgraphSize> expectedReplacementSubgraphSizes{ { 1, 1, 1 },
+                                                                        { 1, 1, 1 } };
+    std::vector<SubgraphView::InputSlots> expectedSubstitutableInputSlots
+    {
+        ConvertReferenceTypeToPointerType(layersInGraph.at("conv1 layer")->GetInputSlots()),
+        ConvertReferenceTypeToPointerType(layersInGraph.at("conv2 layer")->GetInputSlots())
+    };
+    std::vector<SubgraphView::OutputSlots> expectedSubstitutableOutputSlots
+    {
+        ConvertReferenceTypeToPointerType(layersInGraph.at("conv1 layer")->GetOutputSlots()),
+        ConvertReferenceTypeToPointerType(layersInGraph.at("conv2 layer")->GetOutputSlots())
+    };
+    std::vector<SubgraphView::Layers> expectedSubstitutableLayers
+    {
+        { layersInGraph.at("conv1 layer") },
+        { layersInGraph.at("conv2 layer") }
+    };
+
+    for (size_t substitutionIndex = 0; substitutionIndex < substitutions.size(); substitutionIndex++)
+    {
+        CheckSubstitution(substitutions.at(substitutionIndex),
+                          expectedSubstitutableSubgraphSizes.at(substitutionIndex),
+                          expectedReplacementSubgraphSizes.at(substitutionIndex),
+                          expectedSubstitutableInputSlots.at(substitutionIndex),
+                          expectedSubstitutableOutputSlots.at(substitutionIndex),
+                          expectedSubstitutableLayers.at(substitutionIndex));
+    }
+
+    // --------------------------
+    // Check the failed subgraphs
+    // --------------------------
+
+    const OptimizationViews::Subgraphs& failedSubgraphs = optimizationViews.GetFailedSubgraphs();
+    BOOST_TEST(failedSubgraphs.size() == 2);
+
+    std::vector<ExpectedSubgraphSize> expectedFailedSubgraphSizes{ { 1, 1, 2 },
+                                                                   { 1, 1, 1 } };
+    std::vector<SubgraphView::InputSlots> expectedFailedInputSlots
+    {
+        ConvertReferenceTypeToPointerType(layersInGraph.at("pooling1 layer")->GetInputSlots()),
+        ConvertReferenceTypeToPointerType(layersInGraph.at("pooling3 layer")->GetInputSlots())
+    };
+    std::vector<SubgraphView::OutputSlots> expectedFailedOutputSlots
+    {
+        ConvertReferenceTypeToPointerType(layersInGraph.at("pooling2 layer")->GetOutputSlots()),
+        ConvertReferenceTypeToPointerType(layersInGraph.at("pooling3 layer")->GetOutputSlots())
+    };
+    std::vector<SubgraphView::Layers> expectedFailedLayers
+    {
+        { layersInGraph.at("pooling1 layer"),
+          layersInGraph.at("pooling2 layer") },
+        { layersInGraph.at("pooling3 layer") }
+    };
+
+    for (size_t failedIndex = 0; failedIndex < failedSubgraphs.size(); failedIndex++)
+    {
+        CheckFailedSubgraph(failedSubgraphs.at(failedIndex),
+                            expectedFailedSubgraphSizes.at(failedIndex),
+                            expectedFailedInputSlots.at(failedIndex),
+                            expectedFailedOutputSlots.at(failedIndex),
+                            expectedFailedLayers.at(failedIndex));
+    }
+
+    // -----------------------------
+    // Check the untouched subgraphs
+    // -----------------------------
+
+    BOOST_TEST(optimizationViews.GetUntouchedSubgraphs().empty());
+}
+
+// The input subgraph contains only unoptimizable layers ("unoptimizable" is added to the layer's name)
+void FullyUnoptimizableSubgraphTestImpl1()
+{
+    Graph graph;
+    LayerNameToLayerMap layersInGraph;
+
+    // Create a fully optimizable subgraph
+    SubgraphViewSelector::SubgraphViewPtr subgraphPtr = BuildFullyUnoptimizableSubgraph1(graph, layersInGraph);
+    BOOST_TEST((subgraphPtr != nullptr));
+
+    const SubgraphView::InputSlots&  subgraphInputSlots  = subgraphPtr->GetInputSlots();
+    const SubgraphView::OutputSlots& subgraphOutputSlots = subgraphPtr->GetOutputSlots();
+    const SubgraphView::Layers&      subgraphLayers      = subgraphPtr->GetLayers();
+
+    BOOST_TEST(subgraphInputSlots.size()  == 1);
+    BOOST_TEST(subgraphOutputSlots.size() == 1);
+    BOOST_TEST(subgraphLayers.size()      == 1);
+
+    BOOST_TEST(Contains(layersInGraph, "conv layer unoptimizable"));
+
+    // Create a mock backend object
+    auto backendObjPtr = CreateBackendObject(MockBackendId());
+    BOOST_TEST((backendObjPtr != nullptr));
+
+    // Optimize the subgraph
+    OptimizationViews optimizationViews;
+
+    // Check that the optimization is carried out correctly
+    BOOST_CHECK_NO_THROW(optimizationViews = backendObjPtr->OptimizeSubgraphView(*subgraphPtr));
+
+    // ============================================================================
+    // The expected results are:
+    //  - No substitutions
+    //  - No failed subgraphs
+    //  - Exactly one untouched subgraph, corresponding to the whole input subgraph
+    // ============================================================================
+
+    // -----------------------
+    // Check the substitutions
+    // -----------------------
+
+    BOOST_TEST(optimizationViews.GetSubstitutions().empty());
+
+    // --------------------------
+    // Check the failed subgraphs
+    // --------------------------
+
+    BOOST_TEST(optimizationViews.GetFailedSubgraphs().empty());
+
+    // -----------------------------
+    // Check the untouched subgraphs
+    // -----------------------------
+
+    const OptimizationViews::Subgraphs& untouchedSubgraphs = optimizationViews.GetUntouchedSubgraphs();
+    BOOST_TEST(untouchedSubgraphs.size() == 1);
+
+    CheckUntouchedSubgraph(untouchedSubgraphs.at(0),
+                           { subgraphInputSlots.size(), subgraphOutputSlots.size(), subgraphLayers.size() },
+                           subgraphInputSlots,
+                           subgraphOutputSlots,
+                           subgraphLayers);
+}
+
+// The input subgraph contains some unoptimizable layers ("unoptimizable" is added to the layer's name)
+void PartiallyOptimizableSubgraphTestImpl1()
+{
+    Graph graph;
+    LayerNameToLayerMap layersInGraph;
+
+    // Create a fully optimizable subgraph
+    SubgraphViewSelector::SubgraphViewPtr subgraphPtr = BuildPartiallyOptimizableSubgraph1(graph, layersInGraph);
+    BOOST_TEST((subgraphPtr != nullptr));
+
+    const SubgraphView::InputSlots&  subgraphInputSlots  = subgraphPtr->GetInputSlots();
+    const SubgraphView::OutputSlots& subgraphOutputSlots = subgraphPtr->GetOutputSlots();
+    const SubgraphView::Layers&      subgraphLayers      = subgraphPtr->GetLayers();
+
+    BOOST_TEST(subgraphInputSlots.size()  == 1);
+    BOOST_TEST(subgraphOutputSlots.size() == 1);
+    BOOST_TEST(subgraphLayers.size()      == 5);
+
+    BOOST_TEST(Contains(layersInGraph, "conv1 layer"));
+    BOOST_TEST(Contains(layersInGraph, "conv2 layer unoptimizable"));
+    BOOST_TEST(Contains(layersInGraph, "conv3 layer"));
+    BOOST_TEST(Contains(layersInGraph, "conv4 layer unoptimizable"));
+    BOOST_TEST(Contains(layersInGraph, "conv5 layer"));
+
+    // Create a mock backend object
+    auto backendObjPtr = CreateBackendObject(MockBackendId());
+    BOOST_TEST((backendObjPtr != nullptr));
+
+    // Optimize the subgraph
+    OptimizationViews optimizationViews;
+
+    // Check that the optimization is carried out correctly
+    BOOST_CHECK_NO_THROW(optimizationViews = backendObjPtr->OptimizeSubgraphView(*subgraphPtr));
+
+    // ===============================================================================
+    // The expected results are:
+    //  - Exactly three substitutions, corresponding to the optimizable layers
+    //  - No failed subgraphs
+    //  - Exactly two untouched subgraphs, corresponding to the non-optimizable layers
+    // ===============================================================================
+
+    // -----------------------
+    // Check the substitutions
+    // -----------------------
+
+    const OptimizationViews::Substitutions& substitutions = optimizationViews.GetSubstitutions();
+    BOOST_TEST(substitutions.size() == 3);
+
+    std::vector<ExpectedSubgraphSize> expectedSubstitutableSubgraphSizes{ { 1, 1, 1 },
+                                                                          { 1, 1, 1 },
+                                                                          { 1, 1, 1 } };
+    std::vector<ExpectedSubgraphSize> expectedReplacementSubgraphSizes{ { 1, 1, 1 },
+                                                                        { 1, 1, 1 },
+                                                                        { 1, 1, 1 } };
+    std::vector<SubgraphView::InputSlots> expectedSubstitutableInputSlots
+    {
+        ConvertReferenceTypeToPointerType(layersInGraph.at("conv1 layer")->GetInputSlots()),
+        ConvertReferenceTypeToPointerType(layersInGraph.at("conv3 layer")->GetInputSlots()),
+        ConvertReferenceTypeToPointerType(layersInGraph.at("conv5 layer")->GetInputSlots())
+    };
+    std::vector<SubgraphView::OutputSlots> expectedSubstitutableOutputSlots
+    {
+        ConvertReferenceTypeToPointerType(layersInGraph.at("conv1 layer")->GetOutputSlots()),
+        ConvertReferenceTypeToPointerType(layersInGraph.at("conv3 layer")->GetOutputSlots()),
+        ConvertReferenceTypeToPointerType(layersInGraph.at("conv5 layer")->GetOutputSlots())
+    };
+    std::vector<SubgraphView::Layers> expectedSubstitutableLayers
+    {
+        { layersInGraph.at("conv1 layer") },
+        { layersInGraph.at("conv3 layer") },
+        { layersInGraph.at("conv5 layer") }
+    };
+
+    for (size_t substitutionIndex = 0; substitutionIndex < substitutions.size(); substitutionIndex++)
+    {
+        CheckSubstitution(substitutions.at(substitutionIndex),
+                          expectedSubstitutableSubgraphSizes.at(substitutionIndex),
+                          expectedReplacementSubgraphSizes.at(substitutionIndex),
+                          expectedSubstitutableInputSlots.at(substitutionIndex),
+                          expectedSubstitutableOutputSlots.at(substitutionIndex),
+                          expectedSubstitutableLayers.at(substitutionIndex));
+    }
+
+    // --------------------------
+    // Check the failed subgraphs
+    // --------------------------
+
+    BOOST_TEST(optimizationViews.GetFailedSubgraphs().empty());
+
+    // -----------------------------
+    // Check the untouched subgraphs
+    // -----------------------------
+
+    const OptimizationViews::Subgraphs& untouchedSubgraphs = optimizationViews.GetUntouchedSubgraphs();
+    BOOST_TEST(untouchedSubgraphs.size() == 2);
+
+    std::vector<ExpectedSubgraphSize> expectedUntouchedSubgraphSizes{ { 1, 1, 1 },
+                                                                      { 1, 1, 1 } };
+    std::vector<SubgraphView::InputSlots> expectedUntouchedInputSlots
+    {
+        ConvertReferenceTypeToPointerType(layersInGraph.at("conv2 layer unoptimizable")->GetInputSlots()),
+        ConvertReferenceTypeToPointerType(layersInGraph.at("conv4 layer unoptimizable")->GetInputSlots())
+    };
+    std::vector<SubgraphView::OutputSlots> expectedUntouchedOutputSlots
+    {
+        ConvertReferenceTypeToPointerType(layersInGraph.at("conv2 layer unoptimizable")->GetOutputSlots()),
+        ConvertReferenceTypeToPointerType(layersInGraph.at("conv4 layer unoptimizable")->GetOutputSlots())
+    };
+    std::vector<SubgraphView::Layers> expectedUntouchedLayers
+    {
+        { layersInGraph.at("conv2 layer unoptimizable") },
+        { layersInGraph.at("conv4 layer unoptimizable") }
+    };
+
+    for (size_t untouchedIndex = 0; untouchedIndex < untouchedSubgraphs.size(); untouchedIndex++)
+    {
+        CheckUntouchedSubgraph(untouchedSubgraphs.at(untouchedIndex),
+                               expectedUntouchedSubgraphSizes.at(untouchedIndex),
+                               expectedUntouchedInputSlots.at(untouchedIndex),
+                               expectedUntouchedOutputSlots.at(untouchedIndex),
+                               expectedUntouchedLayers.at(untouchedIndex));
+    }
+}
+
+// The input subgraph contains some unoptimizable layers ("unoptimizable" is added to the layer's name),
+// this is meant to test input slots coming from different layers
+void PartiallyOptimizableSubgraphTestImpl2()
+{
+    Graph graph;
+    LayerNameToLayerMap layersInGraph;
+
+    // Create a fully optimizable subgraph
+    SubgraphViewSelector::SubgraphViewPtr subgraphPtr = BuildPartiallyOptimizableSubgraph2(graph, layersInGraph);
+    BOOST_TEST((subgraphPtr != nullptr));
+
+    const SubgraphView::InputSlots&  subgraphInputSlots  = subgraphPtr->GetInputSlots();
+    const SubgraphView::OutputSlots& subgraphOutputSlots = subgraphPtr->GetOutputSlots();
+    const SubgraphView::Layers&      subgraphLayers      = subgraphPtr->GetLayers();
+
+    BOOST_TEST(subgraphInputSlots.size()  == 2);
+    BOOST_TEST(subgraphOutputSlots.size() == 1);
+    BOOST_TEST(subgraphLayers.size()      == 4);
+
+    BOOST_TEST(Contains(layersInGraph, "conv1 layer"));
+    BOOST_TEST(Contains(layersInGraph, "conv2 layer unoptimizable"));
+    BOOST_TEST(Contains(layersInGraph, "conv3 layer"));
+    BOOST_TEST(Contains(layersInGraph, "add layer"));
+
+    // Create a mock backend object
+    auto backendObjPtr = CreateBackendObject(MockBackendId());
+    BOOST_TEST((backendObjPtr != nullptr));
+
+    // Optimize the subgraph
+    OptimizationViews optimizationViews;
+
+    // Check that the optimization is carried out correctly
+    BOOST_CHECK_NO_THROW(optimizationViews = backendObjPtr->OptimizeSubgraphView(*subgraphPtr));
+
+    // ==============================================================================
+    // The expected results are:
+    //  - Exactly one substitution, corresponding to the optimizable layers
+    //  - No failed subgraphs
+    //  - Exactly two untouched subgraphs, corresponding to the non-optimizable layer
+    // ==============================================================================
+
+    // -----------------------
+    // Check the substitutions
+    // -----------------------
+
+    const OptimizationViews::Substitutions& substitutions = optimizationViews.GetSubstitutions();
+    BOOST_TEST(substitutions.size() == 2);
+
+    std::vector<ExpectedSubgraphSize> expectedSubstitutableSubgraphSizes{ { 1, 1, 1 },
+                                                                          { 2, 1, 2 } };
+    std::vector<ExpectedSubgraphSize> expectedReplacementSubgraphSizes{ { 1, 1, 1 },
+                                                                        { 2, 1, 1 } };
+
+    SubgraphView::InputSlots expectedSubstitutableSubgraph2InputSlots =
+        ConvertReferenceTypeToPointerType(layersInGraph.at("conv3 layer")->GetInputSlots());
+    expectedSubstitutableSubgraph2InputSlots.push_back(
+        ConvertReferenceTypeToPointerType(layersInGraph.at("add layer")->GetInputSlot(0)));
+
+    std::vector<SubgraphView::InputSlots> expectedSubstitutableInputSlots
+    {
+        ConvertReferenceTypeToPointerType(layersInGraph.at("conv1 layer")->GetInputSlots()),
+        expectedSubstitutableSubgraph2InputSlots
+    };
+    std::vector<SubgraphView::OutputSlots> expectedSubstitutableOutputSlots
+    {
+        ConvertReferenceTypeToPointerType(layersInGraph.at("conv1 layer")->GetOutputSlots()),
+        ConvertReferenceTypeToPointerType(layersInGraph.at("add layer")->GetOutputSlots())
+    };
+    std::vector<SubgraphView::Layers> expectedSubstitutableLayers
+    {
+        { layersInGraph.at("conv1 layer") },
+        { layersInGraph.at("conv3 layer"),
+          layersInGraph.at("add layer") }
+    };
+
+    for (size_t substitutionIndex = 0; substitutionIndex < substitutions.size(); substitutionIndex++)
+    {
+        CheckSubstitution(substitutions.at(substitutionIndex),
+                          expectedSubstitutableSubgraphSizes.at(substitutionIndex),
+                          expectedReplacementSubgraphSizes.at(substitutionIndex),
+                          expectedSubstitutableInputSlots.at(substitutionIndex),
+                          expectedSubstitutableOutputSlots.at(substitutionIndex),
+                          expectedSubstitutableLayers.at(substitutionIndex));
+    }
+
+    // --------------------------
+    // Check the failed subgraphs
+    // --------------------------
+
+    BOOST_TEST(optimizationViews.GetFailedSubgraphs().empty());
+
+    // -----------------------------
+    // Check the untouched subgraphs
+    // -----------------------------
+
+    const OptimizationViews::Subgraphs& untouchedSubgraphs = optimizationViews.GetUntouchedSubgraphs();
+    BOOST_TEST(untouchedSubgraphs.size() == 1);
+
+    std::vector<ExpectedSubgraphSize> expectedUntouchedSubgraphSizes{ { 1, 1, 1 } };
+    std::vector<SubgraphView::InputSlots> expectedUntouchedInputSlots
+    {
+        ConvertReferenceTypeToPointerType(layersInGraph.at("conv2 layer unoptimizable")->GetInputSlots())
+    };
+    std::vector<SubgraphView::OutputSlots> expectedUntouchedOutputSlots
+    {
+        ConvertReferenceTypeToPointerType(layersInGraph.at("conv2 layer unoptimizable")->GetOutputSlots())
+    };
+    std::vector<SubgraphView::Layers> expectedUntouchedLayers
+    {
+        { layersInGraph.at("conv2 layer unoptimizable") }
+    };
+
+    for (size_t untouchedIndex = 0; untouchedIndex < untouchedSubgraphs.size(); untouchedIndex++)
+    {
+        CheckUntouchedSubgraph(untouchedSubgraphs.at(untouchedIndex),
+                               expectedUntouchedSubgraphSizes.at(untouchedIndex),
+                               expectedUntouchedInputSlots.at(untouchedIndex),
+                               expectedUntouchedOutputSlots.at(untouchedIndex),
+                               expectedUntouchedLayers.at(untouchedIndex));
+    }
+}
+
+} // Anonymous namespace
+
+BOOST_AUTO_TEST_SUITE(OptimizeSubGraph)
+
+BOOST_AUTO_TEST_CASE(FullyUnsupportedSubgraph1)     { FullyUnsupporteSubgraphTestImpl1();      }
+BOOST_AUTO_TEST_CASE(FullyUnsupportedSubgraph2)     { FullyUnsupporteSubgraphTestImpl2();      }
+BOOST_AUTO_TEST_CASE(FullyOptimizableSubgraph1)     { FullyOptimizableSubgraphTestImpl1();     }
+BOOST_AUTO_TEST_CASE(FullyOptimizableSubgraph2)     { FullyOptimizableSubgraphTestImpl2();     }
+BOOST_AUTO_TEST_CASE(PartiallySupportedSubgraph)    { PartiallySupportedSubgraphTestImpl();    }
+BOOST_AUTO_TEST_CASE(FullyUnoptimizableSubgraph)    { FullyUnoptimizableSubgraphTestImpl1();   }
+BOOST_AUTO_TEST_CASE(PartiallyOptimizableSubgraph1) { PartiallyOptimizableSubgraphTestImpl1(); }
+BOOST_AUTO_TEST_CASE(PartiallyOptimizableSubgraph2) { PartiallyOptimizableSubgraphTestImpl2(); }
+
+BOOST_AUTO_TEST_SUITE_END()