diff --git a/app/code/Magento/CatalogImportExport/Model/Import/Product.php b/app/code/Magento/CatalogImportExport/Model/Import/Product.php
index 57498355c51a6..2005eb49493e2 100644
--- a/app/code/Magento/CatalogImportExport/Model/Import/Product.php
+++ b/app/code/Magento/CatalogImportExport/Model/Import/Product.php
@@ -1963,7 +1963,7 @@ protected function _saveStockItem()
                 $productIdsToReindex[] = $row['product_id'];
 
                 $row['website_id'] = $this->stockConfiguration->getDefaultScopeId();
-                $row['stock_id'] = $this->stockRegistry->getStock()->getStockId();
+                $row['stock_id'] = $this->stockRegistry->getStock($row['website_id'])->getStockId();
 
                 $stockItemDo = $this->stockRegistry->getStockItem($row['product_id'], $row['website_id']);
                 $existStockData = $stockItemDo->getData();
diff --git a/app/code/Magento/CatalogInventory/Api/StockRegistryInterface.php b/app/code/Magento/CatalogInventory/Api/StockRegistryInterface.php
index 27b45dc677163..2566aff49b0dc 100644
--- a/app/code/Magento/CatalogInventory/Api/StockRegistryInterface.php
+++ b/app/code/Magento/CatalogInventory/Api/StockRegistryInterface.php
@@ -12,10 +12,10 @@
 interface StockRegistryInterface
 {
     /**
-     * @param int|null $stockId
+     * @param int $scopeId
      * @return \Magento\CatalogInventory\Api\Data\StockInterface
      */
-    public function getStock($stockId = null);
+    public function getStock($scopeId = null);
 
     /**
      * @param int $productId
diff --git a/app/code/Magento/CatalogInventory/Api/StockStatusCriteriaInterface.php b/app/code/Magento/CatalogInventory/Api/StockStatusCriteriaInterface.php
index 44d3c1be11fab..bb3d101e97f9f 100644
--- a/app/code/Magento/CatalogInventory/Api/StockStatusCriteriaInterface.php
+++ b/app/code/Magento/CatalogInventory/Api/StockStatusCriteriaInterface.php
@@ -15,7 +15,7 @@ interface StockStatusCriteriaInterface extends \Magento\Framework\Api\CriteriaIn
      * Add Criteria object
      *
      * @param \Magento\CatalogInventory\Api\StockStatusCriteriaInterface $criteria
-     * @return void
+     * @return bool
      */
     public function addCriteria(\Magento\CatalogInventory\Api\StockStatusCriteriaInterface $criteria);
 
@@ -23,7 +23,7 @@ public function addCriteria(\Magento\CatalogInventory\Api\StockStatusCriteriaInt
      * Filter by scope(s)
      *
      * @param int $scope
-     * @return void
+     * @return bool
      */
     public function setScopeFilter($scope);
 
@@ -31,7 +31,7 @@ public function setScopeFilter($scope);
      * Add product(s) filter
      *
      * @param int $products
-     * @return void
+     * @return bool
      */
     public function setProductsFilter($products);
 
@@ -39,7 +39,7 @@ public function setProductsFilter($products);
      * Add filter by quantity
      *
      * @param float $qty
-     * @return void
+     * @return bool
      */
     public function setQtyFilter($qty);
 }
diff --git a/app/code/Magento/CatalogInventory/Helper/Stock.php b/app/code/Magento/CatalogInventory/Helper/Stock.php
index 4706a60bf5250..0474515b954b7 100644
--- a/app/code/Magento/CatalogInventory/Helper/Stock.php
+++ b/app/code/Magento/CatalogInventory/Helper/Stock.php
@@ -6,7 +6,6 @@
 namespace Magento\CatalogInventory\Helper;
 
 use Magento\CatalogInventory\Model\Spi\StockRegistryProviderInterface;
-use Magento\CatalogInventory\Model\Spi\StockResolverInterface;
 use Magento\Store\Model\StoreManagerInterface;
 use Magento\Framework\App\Config\ScopeConfigInterface;
 use Magento\CatalogInventory\Model\ResourceModel\Stock\StatusFactory;
@@ -48,30 +47,22 @@ class Stock
      */
     private $stockRegistryProvider;
 
-    /**
-     * @var StockResolverInterface
-     */
-    protected $stockResolver;
-
     /**
      * @param StoreManagerInterface $storeManager
      * @param ScopeConfigInterface $scopeConfig
      * @param StatusFactory $stockStatusFactory
      * @param StockRegistryProviderInterface $stockRegistryProvider
-     * @param StockResolverInterface $stockResolver
      */
     public function __construct(
         StoreManagerInterface $storeManager,
         ScopeConfigInterface $scopeConfig,
         StatusFactory $stockStatusFactory,
-        StockRegistryProviderInterface $stockRegistryProvider,
-        StockResolverInterface $stockResolver
+        StockRegistryProviderInterface $stockRegistryProvider
     ) {
         $this->storeManager = $storeManager;
         $this->scopeConfig = $scopeConfig;
         $this->stockStatusFactory  = $stockStatusFactory;
         $this->stockRegistryProvider = $stockRegistryProvider;
-        $this->stockResolver = $stockResolver;
     }
 
     /**
@@ -84,9 +75,8 @@ public function __construct(
     public function assignStatusToProduct(Product $product, $stockStatus = null)
     {
         if ($stockStatus === null) {
-            $productId = $product->getId();
-            $stockId = $this->stockResolver->getStockId($productId, $product->getStore()->getWebsiteId());
-            $stockStatus = $this->stockRegistryProvider->getStockStatus($productId, $stockId);
+            $websiteId = $product->getStore()->getWebsiteId();
+            $stockStatus = $this->stockRegistryProvider->getStockStatus($product->getId(), $websiteId);
             $status = $stockStatus->getStockStatus();
         }
         $product->setIsSalable($status);
@@ -103,8 +93,7 @@ public function addStockStatusToProducts(AbstractCollection $productCollection)
         $websiteId = $this->storeManager->getStore($productCollection->getStoreId())->getWebsiteId();
         foreach ($productCollection as $product) {
             $productId = $product->getId();
-            $stockId = $this->stockResolver->getStockId($productId, $websiteId);
-            $stockStatus = $this->stockRegistryProvider->getStockStatus($productId, $stockId);
+            $stockStatus = $this->stockRegistryProvider->getStockStatus($productId, $websiteId);
             $status = $stockStatus->getStockStatus();
             $product->setIsSalable($status);
         }
diff --git a/app/code/Magento/CatalogInventory/Model/Spi/StockRegistryProviderInterface.php b/app/code/Magento/CatalogInventory/Model/Spi/StockRegistryProviderInterface.php
index a08aa33533301..8fb68a2c997be 100644
--- a/app/code/Magento/CatalogInventory/Model/Spi/StockRegistryProviderInterface.php
+++ b/app/code/Magento/CatalogInventory/Model/Spi/StockRegistryProviderInterface.php
@@ -11,22 +11,22 @@
 interface StockRegistryProviderInterface
 {
     /**
-     * @param int|null $stockId
+     * @param int $scopeId
      * @return \Magento\CatalogInventory\Api\Data\StockInterface
      */
-    public function getStock($stockId);
+    public function getStock($scopeId);
 
     /**
      * @param int $productId
-     * @param int $stockId
+     * @param int $scopeId
      * @return \Magento\CatalogInventory\Api\Data\StockItemInterface
      */
-    public function getStockItem($productId, $stockId);
+    public function getStockItem($productId, $scopeId);
 
     /**
      * @param int $productId
-     * @param int $stockId
+     * @param int $scopeId
      * @return \Magento\CatalogInventory\Api\Data\StockStatusInterface
      */
-    public function getStockStatus($productId, $stockId);
+    public function getStockStatus($productId, $scopeId);
 }
diff --git a/app/code/Magento/CatalogInventory/Model/Spi/StockResolverInterface.php b/app/code/Magento/CatalogInventory/Model/Spi/StockResolverInterface.php
deleted file mode 100644
index b4f9df8f079da..0000000000000
--- a/app/code/Magento/CatalogInventory/Model/Spi/StockResolverInterface.php
+++ /dev/null
@@ -1,19 +0,0 @@
-<?php
-/**
- * Copyright © 2015 Magento. All rights reserved.
- * See COPYING.txt for license details.
- */
-namespace Magento\CatalogInventory\Model\Spi;
-
-/**
- * Interface StockResolverInterface
- */
-interface StockResolverInterface
-{
-    /**
-     * @param int $productId
-     * @param int $websiteId
-     * @return int
-     */
-    public function getStockId($productId, $websiteId);
-}
diff --git a/app/code/Magento/CatalogInventory/Model/Stock/Item.php b/app/code/Magento/CatalogInventory/Model/Stock/Item.php
index b97977fd3c013..3c4c7bfdf143f 100644
--- a/app/code/Magento/CatalogInventory/Model/Stock/Item.php
+++ b/app/code/Magento/CatalogInventory/Model/Stock/Item.php
@@ -177,7 +177,7 @@ public function getStockId()
     {
         $stockId = $this->getData(static::STOCK_ID);
         if ($stockId === null) {
-            $stockId = $this->stockRegistry->getStock()->getStockId();
+            $stockId = $this->stockRegistry->getStock($this->getWebsiteId())->getStockId();
         }
         return (int) $stockId;
     }
diff --git a/app/code/Magento/CatalogInventory/Model/StockIndex.php b/app/code/Magento/CatalogInventory/Model/StockIndex.php
index d961f52ff519f..4c6f6521c9794 100644
--- a/app/code/Magento/CatalogInventory/Model/StockIndex.php
+++ b/app/code/Magento/CatalogInventory/Model/StockIndex.php
@@ -13,7 +13,6 @@
 use Magento\Catalog\Model\ProductFactory;
 use Magento\CatalogInventory\Api\StockIndexInterface;
 use Magento\CatalogInventory\Model\Spi\StockRegistryProviderInterface;
-use Magento\CatalogInventory\Model\Spi\StockResolverInterface;
 use Magento\Catalog\Api\ProductRepositoryInterface;
 
 /**
@@ -56,31 +55,22 @@ class StockIndex implements StockIndexInterface
      */
     protected $productTypes = [];
 
-
-    /**
-     * @var StockResolverInterface
-     */
-    protected $stockResolver;
-
     /**
      * @param StockRegistryProviderInterface $stockRegistryProvider
      * @param ProductRepositoryInterface $productRepository
      * @param ProductWebsite $productWebsite
      * @param ProductType $productType
-     * @param StockResolverInterface $stockResolver
      */
     public function __construct(
         StockRegistryProviderInterface $stockRegistryProvider,
         ProductRepositoryInterface $productRepository,
         ProductWebsite $productWebsite,
-        ProductType $productType,
-        StockResolverInterface $stockResolver
+        ProductType $productType
     ) {
         $this->stockRegistryProvider = $stockRegistryProvider;
         $this->productRepository = $productRepository;
         $this->productWebsite = $productWebsite;
         $this->productType = $productType;
-        $this->stockResolver = $stockResolver;
     }
 
     /**
@@ -122,8 +112,7 @@ public function rebuild($productId = null, $scopeId = null)
      */
     public function updateProductStockStatus($productId, $websiteId)
     {
-        $stockId = $this->stockResolver->getStockId($productId, $websiteId);
-        $item = $this->stockRegistryProvider->getStockItem($productId, $stockId);
+        $item = $this->stockRegistryProvider->getStockItem($productId, $websiteId);
 
         $status = \Magento\CatalogInventory\Model\Stock\Status::STATUS_IN_STOCK;
         $qty = 0;
@@ -242,8 +231,7 @@ protected function processParents($productId, $websiteId)
         }
 
         foreach ($parentIds as $parentId) {
-            $stockId = $this->stockResolver->getStockId($productId, $websiteId);
-            $item = $this->stockRegistryProvider->getStockItem($parentId, $stockId);
+            $item = $this->stockRegistryProvider->getStockItem($parentId, $websiteId);
             $status = \Magento\CatalogInventory\Model\Stock\Status::STATUS_IN_STOCK;
             $qty = 0;
             if ($item->getItemId()) {
diff --git a/app/code/Magento/CatalogInventory/Model/StockManagement.php b/app/code/Magento/CatalogInventory/Model/StockManagement.php
index 7b08d2a757ebc..9415c464c18c1 100644
--- a/app/code/Magento/CatalogInventory/Model/StockManagement.php
+++ b/app/code/Magento/CatalogInventory/Model/StockManagement.php
@@ -10,7 +10,6 @@
 use Magento\CatalogInventory\Api\StockManagementInterface;
 use Magento\CatalogInventory\Model\ResourceModel\QtyCounterInterface;
 use Magento\CatalogInventory\Model\Spi\StockRegistryProviderInterface;
-use Magento\CatalogInventory\Model\Spi\StockResolverInterface;
 use Magento\Catalog\Api\ProductRepositoryInterface;
 use Magento\CatalogInventory\Model\ResourceModel\Stock as ResourceStock;
 
@@ -49,11 +48,6 @@ class StockManagement implements StockManagementInterface
      */
     private $qtyCounter;
 
-    /**
-     * @var StockResolverInterface
-     */
-    protected $stockResolver;
-
     /**
      * @param ResourceStock $stockResource
      * @param StockRegistryProviderInterface $stockRegistryProvider
@@ -61,7 +55,6 @@ class StockManagement implements StockManagementInterface
      * @param StockConfigurationInterface $stockConfiguration
      * @param ProductRepositoryInterface $productRepository
      * @param QtyCounterInterface $qtyCounter
-     * @param StockResolverInterface $stockResolver
      */
     public function __construct(
         ResourceStock $stockResource,
@@ -69,8 +62,7 @@ public function __construct(
         StockState $stockState,
         StockConfigurationInterface $stockConfiguration,
         ProductRepositoryInterface $productRepository,
-        QtyCounterInterface $qtyCounter,
-        StockResolverInterface $stockResolver
+        QtyCounterInterface $qtyCounter
     ) {
         $this->stockRegistryProvider = $stockRegistryProvider;
         $this->stockState = $stockState;
@@ -78,7 +70,6 @@ public function __construct(
         $this->productRepository = $productRepository;
         $this->qtyCounter = $qtyCounter;
         $this->resource = $stockResource;
-        $this->stockResolver = $stockResolver;
     }
 
     /**
@@ -93,9 +84,9 @@ public function __construct(
      */
     public function registerProductsSale($items, $websiteId = null)
     {
-        if (!$websiteId) {
-                $websiteId = $this->stockConfiguration->getDefaultScopeId();
-        }
+        //if (!$websiteId) {
+            $websiteId = $this->stockConfiguration->getDefaultScopeId();
+        //}
         $this->getResource()->beginTransaction();
         $lockedItems = $this->getResource()->lockProductsStock(array_keys($items), $websiteId);
         $fullSaveItems = $registeredItems = [];
@@ -103,8 +94,7 @@ public function registerProductsSale($items, $websiteId = null)
             $productId = $lockedItemRecord['product_id'];
             /** @var StockItemInterface $stockItem */
             $orderedQty = $items[$productId];
-            $stockId = $this->stockResolver->getStockId($productId, $websiteId);
-            $stockItem = $this->stockRegistryProvider->getStockItem($productId, $stockId);
+            $stockItem = $this->stockRegistryProvider->getStockItem($productId, $websiteId);
             $canSubtractQty = $stockItem->getItemId() && $this->canSubtractQty($stockItem);
             if (!$canSubtractQty || !$this->stockConfiguration->isQty($lockedItemRecord['type_id'])) {
                 continue;
@@ -142,9 +132,9 @@ public function registerProductsSale($items, $websiteId = null)
      */
     public function revertProductsSale($items, $websiteId = null)
     {
-        if (!$websiteId) {
-            $websiteId = $this->stockConfiguration->getDefaultScopeId();
-        }
+        //if (!$websiteId) {
+        $websiteId = $this->stockConfiguration->getDefaultScopeId();
+        //}
         $this->qtyCounter->correctItemsQty($items, $websiteId, '+');
         return true;
     }
@@ -159,11 +149,10 @@ public function revertProductsSale($items, $websiteId = null)
      */
     public function backItemQty($productId, $qty, $scopeId = null)
     {
-        if (!$scopeId) {
-            $scopeId = $this->stockConfiguration->getDefaultScopeId();
-        }
-        $stockId = $this->stockResolver->getStockId($productId, $scopeId);
-        $stockItem = $this->stockRegistryProvider->getStockItem($productId, $stockId);
+        //if (!$scopeId) {
+        $scopeId = $this->stockConfiguration->getDefaultScopeId();
+        //}
+        $stockItem = $this->stockRegistryProvider->getStockItem($productId, $scopeId);
         if ($stockItem->getItemId() && $this->stockConfiguration->isQty($this->getProductType($productId))) {
             if ($this->canSubtractQty($stockItem)) {
                 $stockItem->setQty($stockItem->getQty() + $qty);
diff --git a/app/code/Magento/CatalogInventory/Model/StockRegistry.php b/app/code/Magento/CatalogInventory/Model/StockRegistry.php
index d72719fdb3a05..fda30523c39ab 100644
--- a/app/code/Magento/CatalogInventory/Model/StockRegistry.php
+++ b/app/code/Magento/CatalogInventory/Model/StockRegistry.php
@@ -11,9 +11,7 @@
 use Magento\CatalogInventory\Api\StockItemCriteriaInterfaceFactory;
 use Magento\CatalogInventory\Api\StockItemRepositoryInterface;
 use Magento\CatalogInventory\Api\StockRegistryInterface;
-use Magento\CatalogInventory\Model\Spi\StockResolverInterface;
 use Magento\CatalogInventory\Model\Spi\StockRegistryProviderInterface;
-use Magento\CatalogInventory\Model\Spi\StockStateProviderInterface;
 
 /**
  * Class StockRegistry
@@ -47,49 +45,37 @@ class StockRegistry implements StockRegistryInterface
      */
     protected $criteriaFactory;
 
-    /**
-     * @var \Magento\CatalogInventory\Model\Spi\StockResolverInterface
-     */
-    protected $stockResolver;
-
-    /**
-     * @var StockStateProviderInterface
-     */
-    protected $stockStateProvider;
-
     /**
      * @param StockConfigurationInterface $stockConfiguration
      * @param StockRegistryProviderInterface $stockRegistryProvider
      * @param StockItemRepositoryInterface $stockItemRepository
      * @param StockItemCriteriaInterfaceFactory $criteriaFactory
      * @param ProductFactory $productFactory
-     * @param StockResolverInterface $stockResolver
-     * @param StockStateProviderInterface $stockStateProvider
      */
     public function __construct(
         StockConfigurationInterface $stockConfiguration,
         StockRegistryProviderInterface $stockRegistryProvider,
         StockItemRepositoryInterface $stockItemRepository,
         StockItemCriteriaInterfaceFactory $criteriaFactory,
-        ProductFactory $productFactory,
-        StockResolverInterface $stockResolver,
-        StockStateProviderInterface $stockStateProvider
+        ProductFactory $productFactory
     ) {
         $this->stockConfiguration = $stockConfiguration;
         $this->stockRegistryProvider = $stockRegistryProvider;
         $this->stockItemRepository = $stockItemRepository;
         $this->criteriaFactory = $criteriaFactory;
         $this->productFactory = $productFactory;
-        $this->stockResolver = $stockResolver;
-        $this->stockStateProvider = $stockStateProvider;
     }
 
     /**
-     * @inheritdoc
+     * @param int $scopeId
+     * @return \Magento\CatalogInventory\Api\Data\StockInterface
      */
-    public function getStock($stockId = null)
+    public function getStock($scopeId = null)
     {
-        return $this->stockRegistryProvider->getStock($stockId);
+        //if (!$scopeId) {
+        $scopeId = $this->stockConfiguration->getDefaultScopeId();
+        //}
+        return $this->stockRegistryProvider->getStock($scopeId);
     }
 
     /**
@@ -99,12 +85,10 @@ public function getStock($stockId = null)
      */
     public function getStockItem($productId, $scopeId = null)
     {
-        if (!$scopeId) {
-            $scopeId = $this->stockConfiguration->getDefaultScopeId();
-        }
-        $stockId = $this->stockResolver->getStockId($productId, $scopeId);
-
-        return $this->stockRegistryProvider->getStockItem($productId, $stockId);
+        //if (!$scopeId) {
+        $scopeId = $this->stockConfiguration->getDefaultScopeId();
+        //}
+        return $this->stockRegistryProvider->getStockItem($productId, $scopeId);
     }
 
     /**
@@ -115,12 +99,11 @@ public function getStockItem($productId, $scopeId = null)
      */
     public function getStockItemBySku($productSku, $scopeId = null)
     {
-        if (!$scopeId) {
-            $scopeId = $this->stockConfiguration->getDefaultScopeId();
-        }
+        //if (!$scopeId) {
+        $scopeId = $this->stockConfiguration->getDefaultScopeId();
+        //}
         $productId = $this->resolveProductId($productSku);
-        $stockId = $this->stockResolver->getStockId($productId, $scopeId);
-        return $this->stockRegistryProvider->getStockItem($productId, $stockId);
+        return $this->stockRegistryProvider->getStockItem($productId, $scopeId);
     }
 
     /**
@@ -130,11 +113,10 @@ public function getStockItemBySku($productSku, $scopeId = null)
      */
     public function getStockStatus($productId, $scopeId = null)
     {
-        if (!$scopeId) {
-            $scopeId = $this->stockConfiguration->getDefaultScopeId();
-        }
-        $stockId = $this->stockResolver->getStockId($productId, $scopeId);
-        return $this->stockRegistryProvider->getStockStatus($productId, $stockId);
+        //if (!$scopeId) {
+        $scopeId = $this->stockConfiguration->getDefaultScopeId();
+        //}
+        return $this->stockRegistryProvider->getStockStatus($productId, $scopeId);
     }
 
     /**
@@ -145,12 +127,11 @@ public function getStockStatus($productId, $scopeId = null)
      */
     public function getStockStatusBySku($productSku, $scopeId = null)
     {
-        if (!$scopeId) {
-            $scopeId = $this->stockConfiguration->getDefaultScopeId();
-        }
+        //if (!$scopeId) {
+        $scopeId = $this->stockConfiguration->getDefaultScopeId();
+        //}
         $productId = $this->resolveProductId($productSku);
-        $stockId = $this->stockResolver->getStockId($productId, $scopeId);
-        return $this->getStockStatus($productId, $stockId);
+        return $this->getStockStatus($productId, $scopeId);
     }
 
     /**
@@ -161,11 +142,10 @@ public function getStockStatusBySku($productSku, $scopeId = null)
      */
     public function getProductStockStatus($productId, $scopeId = null)
     {
-        if (!$scopeId) {
-            $scopeId = $this->stockConfiguration->getDefaultScopeId();
-        }
-        $stockId = $this->stockResolver->getStockId($productId, $scopeId);
-        $stockStatus = $this->getStockStatus($productId, $stockId);
+        //if (!$scopeId) {
+        $scopeId = $this->stockConfiguration->getDefaultScopeId();
+        //}
+        $stockStatus = $this->getStockStatus($productId, $scopeId);
         return $stockStatus->getStockStatus();
     }
 
@@ -177,12 +157,11 @@ public function getProductStockStatus($productId, $scopeId = null)
      */
     public function getProductStockStatusBySku($productSku, $scopeId = null)
     {
-        if (!$scopeId) {
-            $scopeId = $this->stockConfiguration->getDefaultScopeId();
-        }
+        //if (!$scopeId) {
+        $scopeId = $this->stockConfiguration->getDefaultScopeId();
+        //}
         $productId = $this->resolveProductId($productSku);
-        $stockId = $this->stockResolver->getStockId($productId, $scopeId);
-        return $this->getProductStockStatus($productId, $stockId);
+        return $this->getProductStockStatus($productId, $scopeId);
     }
 
     /**
diff --git a/app/code/Magento/CatalogInventory/Model/StockRegistryProvider.php b/app/code/Magento/CatalogInventory/Model/StockRegistryProvider.php
index 0e103e2cddd14..e8f7ae5cc723f 100644
--- a/app/code/Magento/CatalogInventory/Model/StockRegistryProvider.php
+++ b/app/code/Magento/CatalogInventory/Model/StockRegistryProvider.php
@@ -15,13 +15,11 @@
 use Magento\CatalogInventory\Api\StockCriteriaInterfaceFactory;
 use Magento\CatalogInventory\Api\StockItemCriteriaInterfaceFactory;
 use Magento\CatalogInventory\Api\StockStatusCriteriaInterfaceFactory;
-use Magento\CatalogInventory\Api\StockConfigurationInterface;
 use Magento\Store\Model\StoreManagerInterface;
 
 /**
  * Class StockRegistryProvider
  * @SuppressWarnings(PHPMD.CouplingBetweenObjects)
- * @SuppressWarnings(PHPMD.ExcessiveParameterList)
  */
 class StockRegistryProvider implements StockRegistryProviderInterface
 {
@@ -70,11 +68,6 @@ class StockRegistryProvider implements StockRegistryProviderInterface
      */
     protected $stockStatusCriteriaFactory;
 
-    /**
-     * @var StockConfigurationInterface
-     */
-    protected $stockConfiguration;
-
     /**
      * @var array
      */
@@ -100,7 +93,6 @@ class StockRegistryProvider implements StockRegistryProviderInterface
      * @param StockCriteriaInterfaceFactory $stockCriteriaFactory
      * @param StockItemCriteriaInterfaceFactory $stockItemCriteriaFactory
      * @param StockStatusCriteriaInterfaceFactory $stockStatusCriteriaFactory
-     * @param StockConfigurationInterface $stockConfiguration
      */
     public function __construct(
         StockRepositoryInterface $stockRepository,
@@ -111,8 +103,7 @@ public function __construct(
         StockStatusInterfaceFactory $stockStatusFactory,
         StockCriteriaInterfaceFactory $stockCriteriaFactory,
         StockItemCriteriaInterfaceFactory $stockItemCriteriaFactory,
-        StockStatusCriteriaInterfaceFactory $stockStatusCriteriaFactory,
-        StockConfigurationInterface $stockConfiguration
+        StockStatusCriteriaInterfaceFactory $stockStatusCriteriaFactory
     ) {
         $this->stockRepository = $stockRepository;
         $this->stockFactory = $stockFactory;
@@ -120,49 +111,43 @@ public function __construct(
         $this->stockItemFactory = $stockItemFactory;
         $this->stockStatusRepository = $stockStatusRepository;
         $this->stockStatusFactory = $stockStatusFactory;
+
         $this->stockCriteriaFactory = $stockCriteriaFactory;
         $this->stockItemCriteriaFactory = $stockItemCriteriaFactory;
         $this->stockStatusCriteriaFactory = $stockStatusCriteriaFactory;
-        $this->stockConfiguration = $stockConfiguration;
     }
 
     /**
-     * @inheritdoc
+     * @param int|null $scopeId
+     * @return \Magento\CatalogInventory\Api\Data\StockInterface
      */
-    public function getStock($stockId)
+    public function getStock($scopeId)
     {
-        if (!isset($this->stocks[$stockId])) {
-            if ($stockId !== null) {
-                $stock = $this->stockRepository->get($stockId);
-            } else {
-                /** @var \Magento\CatalogInventory\Api\StockCriteriaInterface $criteria */
-                $criteria = $this->stockCriteriaFactory->create();
-                $criteria->setScopeFilter($this->stockConfiguration->getDefaultScopeId());
-                $collection = $this->stockRepository->getList($criteria);
-                $stock = current($collection->getItems());
-            }
+        if (!isset($this->stocks[$scopeId])) {
+            $criteria = $this->stockCriteriaFactory->create();
+            $criteria->setScopeFilter($scopeId);
+            $collection = $this->stockRepository->getList($criteria);
+            $stock = current($collection->getItems());
             if ($stock && $stock->getStockId()) {
-                $this->stocks[$stockId] = $stock;
+                $this->stocks[$scopeId] = $stock;
             } else {
                 return $this->stockFactory->create();
             }
         }
-        return $this->stocks[$stockId];
+        return $this->stocks[$scopeId];
     }
 
     /**
      * @param int $productId
-     * @param int $stockId
+     * @param int $scopeId
      * @return \Magento\CatalogInventory\Api\Data\StockItemInterface
      */
-    public function getStockItem($productId, $stockId)
+    public function getStockItem($productId, $scopeId)
     {
-        $key = $stockId . '/' . $productId;
+        $key = $scopeId . '/' . $productId;
         if (!isset($this->stockItems[$key])) {
-            /** @var \Magento\CatalogInventory\Api\StockItemCriteriaInterface $criteria */
             $criteria = $this->stockItemCriteriaFactory->create();
             $criteria->setProductsFilter($productId);
-            $criteria->setStockFilter($this->getStock($stockId));
             $collection = $this->stockItemRepository->getList($criteria);
             $stockItem = current($collection->getItems());
             if ($stockItem && $stockItem->getItemId()) {
@@ -176,17 +161,16 @@ public function getStockItem($productId, $stockId)
 
     /**
      * @param int $productId
-     * @param int $stockId
+     * @param int $scopeId
      * @return \Magento\CatalogInventory\Api\Data\StockStatusInterface
      */
-    public function getStockStatus($productId, $stockId)
+    public function getStockStatus($productId, $scopeId)
     {
-        $key = $stockId . '/' . $productId;
+        $key = $scopeId . '/' . $productId;
         if (!isset($this->stockStatuses[$key])) {
-            /** @var \Magento\CatalogInventory\Api\stockStatusCriteriaInterface $criteria */
             $criteria = $this->stockStatusCriteriaFactory->create();
             $criteria->setProductsFilter($productId);
-            $criteria->addFilter('stock', 'stock_id', $stockId);
+            $criteria->setScopeFilter($scopeId);
             $collection = $this->stockStatusRepository->getList($criteria);
             $stockStatus = current($collection->getItems());
             if ($stockStatus && $stockStatus->getProductId()) {
diff --git a/app/code/Magento/CatalogInventory/Model/StockResolver.php b/app/code/Magento/CatalogInventory/Model/StockResolver.php
deleted file mode 100644
index 8e7c096d37047..0000000000000
--- a/app/code/Magento/CatalogInventory/Model/StockResolver.php
+++ /dev/null
@@ -1,25 +0,0 @@
-<?php
-/**
- * Copyright © 2015 Magento. All rights reserved.
- * See COPYING.txt for license details.
- */
-namespace Magento\CatalogInventory\Model;
-
-use Magento\CatalogInventory\Model\Spi\StockResolverInterface;
-
-/**
- * Class StockResolver
- */
-class StockResolver implements StockResolverInterface
-{
-    const DEFAULT_STOCK_ID = 1;
-
-    /**
-     * @inheritdoc
-     */
-    public function getStockId($productId, $websiteId)
-    {
-        $stockId = self::DEFAULT_STOCK_ID;
-        return $stockId;
-    }
-}
diff --git a/app/code/Magento/CatalogInventory/Model/StockState.php b/app/code/Magento/CatalogInventory/Model/StockState.php
index e64906691ad79..c3d0dc9aef0fd 100644
--- a/app/code/Magento/CatalogInventory/Model/StockState.php
+++ b/app/code/Magento/CatalogInventory/Model/StockState.php
@@ -9,7 +9,6 @@
 use Magento\CatalogInventory\Api\StockStateInterface;
 use Magento\CatalogInventory\Model\Spi\StockRegistryProviderInterface;
 use Magento\CatalogInventory\Model\Spi\StockStateProviderInterface;
-use Magento\CatalogInventory\Model\Spi\StockResolverInterface;
 
 /**
  * Interface StockState
@@ -31,27 +30,19 @@ class StockState implements StockStateInterface
      */
     protected $stockConfiguration;
 
-    /**
-     * @var StockResolverInterface
-     */
-    protected $stockResolver;
-
     /**
      * @param StockStateProviderInterface $stockStateProvider
      * @param StockRegistryProviderInterface $stockRegistryProvider
      * @param StockConfigurationInterface $stockConfiguration
-     * @param StockResolverInterface $stockResolver
      */
     public function __construct(
         StockStateProviderInterface $stockStateProvider,
         StockRegistryProviderInterface $stockRegistryProvider,
-        StockConfigurationInterface $stockConfiguration,
-        StockResolverInterface $stockResolver
+        StockConfigurationInterface $stockConfiguration
     ) {
         $this->stockStateProvider = $stockStateProvider;
         $this->stockRegistryProvider = $stockRegistryProvider;
         $this->stockConfiguration = $stockConfiguration;
-        $this->stockResolver = $stockResolver;
     }
 
     /**
@@ -64,8 +55,7 @@ public function verifyStock($productId, $scopeId = null)
         if ($scopeId === null) {
             $scopeId = $this->stockConfiguration->getDefaultScopeId();
         }
-        $stockId = $this->stockResolver->getStockId($productId, $scopeId);
-        $stockItem = $this->stockRegistryProvider->getStockItem($productId, $stockId);
+        $stockItem = $this->stockRegistryProvider->getStockItem($productId, $scopeId);
         return $this->stockStateProvider->verifyStock($stockItem);
     }
 
@@ -79,8 +69,7 @@ public function verifyNotification($productId, $scopeId = null)
         if ($scopeId === null) {
             $scopeId = $this->stockConfiguration->getDefaultScopeId();
         }
-        $stockId = $this->stockResolver->getStockId($productId, $scopeId);
-        $stockItem = $this->stockRegistryProvider->getStockItem($productId, $stockId);
+        $stockItem = $this->stockRegistryProvider->getStockItem($productId, $scopeId);
         return $this->stockStateProvider->verifyNotification($stockItem);
     }
 
@@ -98,8 +87,7 @@ public function checkQty($productId, $qty, $scopeId = null)
         if ($scopeId === null) {
             $scopeId = $this->stockConfiguration->getDefaultScopeId();
         }
-        $stockId = $this->stockResolver->getStockId($productId, $scopeId);
-        $stockItem = $this->stockRegistryProvider->getStockItem($productId, $stockId);
+        $stockItem = $this->stockRegistryProvider->getStockItem($productId, $scopeId);
         return $this->stockStateProvider->checkQty($stockItem, $qty);
     }
 
@@ -117,8 +105,7 @@ public function suggestQty($productId, $qty, $scopeId = null)
         if ($scopeId === null) {
             $scopeId = $this->stockConfiguration->getDefaultScopeId();
         }
-        $stockId = $this->stockResolver->getStockId($productId, $scopeId);
-        $stockItem = $this->stockRegistryProvider->getStockItem($productId, $stockId);
+        $stockItem = $this->stockRegistryProvider->getStockItem($productId, $scopeId);
         return $this->stockStateProvider->suggestQty($stockItem, $qty);
     }
 
@@ -134,8 +121,7 @@ public function getStockQty($productId, $scopeId = null)
         if ($scopeId === null) {
             $scopeId = $this->stockConfiguration->getDefaultScopeId();
         }
-        $stockId = $this->stockResolver->getStockId($productId, $scopeId);
-        $stockItem = $this->stockRegistryProvider->getStockItem($productId, $stockId);
+        $stockItem = $this->stockRegistryProvider->getStockItem($productId, $scopeId);
         return $this->stockStateProvider->getStockQty($stockItem);
     }
 
@@ -150,8 +136,7 @@ public function checkQtyIncrements($productId, $qty, $websiteId = null)
         if ($websiteId === null) {
             $websiteId = $this->stockConfiguration->getDefaultScopeId();
         }
-        $stockId = $this->stockResolver->getStockId($productId, $websiteId);
-        $stockItem = $this->stockRegistryProvider->getStockItem($productId, $stockId);
+        $stockItem = $this->stockRegistryProvider->getStockItem($productId, $websiteId);
         return $this->stockStateProvider->checkQtyIncrements($stockItem, $qty);
     }
 
@@ -168,8 +153,7 @@ public function checkQuoteItemQty($productId, $itemQty, $qtyToCheck, $origQty, $
         if ($scopeId === null) {
             $scopeId = $this->stockConfiguration->getDefaultScopeId();
         }
-        $stockId = $this->stockResolver->getStockId($productId, $scopeId);
-        $stockItem = $this->stockRegistryProvider->getStockItem($productId, $stockId);
+        $stockItem = $this->stockRegistryProvider->getStockItem($productId, $scopeId);
         return $this->stockStateProvider->checkQuoteItemQty($stockItem, $itemQty, $qtyToCheck, $origQty);
     }
 }
diff --git a/app/code/Magento/CatalogInventory/Observer/SaveInventoryDataObserver.php b/app/code/Magento/CatalogInventory/Observer/SaveInventoryDataObserver.php
index 84c6e31dbac45..08bf961fb7278 100644
--- a/app/code/Magento/CatalogInventory/Observer/SaveInventoryDataObserver.php
+++ b/app/code/Magento/CatalogInventory/Observer/SaveInventoryDataObserver.php
@@ -11,7 +11,6 @@
 use Magento\CatalogInventory\Api\StockIndexInterface;
 use Magento\CatalogInventory\Api\StockItemRepositoryInterface;
 use Magento\CatalogInventory\Api\StockRegistryInterface;
-use Magento\CatalogInventory\Model\Spi\StockResolverInterface;
 use Magento\Framework\Event\Observer as EventObserver;
 
 class SaveInventoryDataObserver implements ObserverInterface
@@ -36,11 +35,6 @@ class SaveInventoryDataObserver implements ObserverInterface
      */
     protected $stockItemRepository;
 
-    /**
-     * @var StockResolverInterface
-     */
-    protected $stockResolver;
-
     /**
      * @var array
      */
@@ -80,20 +74,17 @@ class SaveInventoryDataObserver implements ObserverInterface
      * @param StockConfigurationInterface $stockConfiguration
      * @param StockRegistryInterface $stockRegistry
      * @param StockItemRepositoryInterface $stockItemRepository
-     * @param StockResolverInterface $stockResolver
      */
     public function __construct(
         StockIndexInterface $stockIndex,
         StockConfigurationInterface $stockConfiguration,
         StockRegistryInterface $stockRegistry,
-        StockItemRepositoryInterface $stockItemRepository,
-        StockResolverInterface $stockResolver
+        StockItemRepositoryInterface $stockItemRepository
     ) {
         $this->stockIndex = $stockIndex;
         $this->stockConfiguration = $stockConfiguration;
         $this->stockRegistry = $stockRegistry;
         $this->stockItemRepository = $stockItemRepository;
-        $this->stockResolver = $stockResolver;
     }
 
     /**
@@ -134,8 +125,7 @@ protected function saveStockItemData($product)
         if (!isset($stockItemData['website_id'])) {
             $stockItemData['website_id'] = $this->stockConfiguration->getDefaultScopeId();
         }
-        $stockItemData['stock_id'] = $this->stockResolver
-            ->getStockId($stockItemData['product_id'], $stockItemData['website_id']);
+        $stockItemData['stock_id'] = $this->stockRegistry->getStock($stockItemData['website_id'])->getStockId();
 
         foreach ($this->paramListToCheck as $dataKey => $configPath) {
             if (null !== $product->getData($configPath['item']) && null === $product->getData($configPath['config'])) {
diff --git a/app/code/Magento/CatalogInventory/Test/Unit/Api/StockRegistryTest.php b/app/code/Magento/CatalogInventory/Test/Unit/Api/StockRegistryTest.php
index 435defef554e5..02c631727a4b5 100644
--- a/app/code/Magento/CatalogInventory/Test/Unit/Api/StockRegistryTest.php
+++ b/app/code/Magento/CatalogInventory/Test/Unit/Api/StockRegistryTest.php
@@ -58,7 +58,6 @@ class StockRegistryTest extends \PHPUnit_Framework_TestCase
     protected $product;
 
     protected $productId = 111;
-    protected $stockId = 112;
     protected $productSku = 'simple';
     protected $websiteId = 111;
 
@@ -136,7 +135,7 @@ protected function tearDown()
 
     public function testGetStock()
     {
-        $this->assertEquals($this->stock, $this->stockRegistry->getStock($this->stockId));
+        $this->assertEquals($this->stock, $this->stockRegistry->getStock($this->websiteId));
     }
 
     public function testGetStockItem()
diff --git a/app/code/Magento/CatalogInventory/Test/Unit/Helper/StockTest.php b/app/code/Magento/CatalogInventory/Test/Unit/Helper/StockTest.php
index 65173103377f4..cb4209de616e7 100644
--- a/app/code/Magento/CatalogInventory/Test/Unit/Helper/StockTest.php
+++ b/app/code/Magento/CatalogInventory/Test/Unit/Helper/StockTest.php
@@ -37,11 +37,6 @@ class StockTest extends \PHPUnit_Framework_TestCase
      */
     protected $statusFactoryMock;
 
-    /**
-     * @var \Magento\CatalogInventory\Model\Spi\StockResolverInterface|\PHPUnit_Framework_MockObject_MockObject
-     */
-    protected $stockResolverMock;
-
     protected function setUp()
     {
         $this->stockRegistryProviderMock = $this->getMockBuilder(
@@ -60,26 +55,18 @@ protected function setUp()
             ->disableOriginalConstructor()
             ->setMethods(['create'])
             ->getMock();
-        $this->stockResolverMock =
-            $this->getMockBuilder('Magento\CatalogInventory\Model\Spi\StockResolverInterface')
-                ->disableOriginalConstructor()
-                ->setMethods(['getStockId'])
-                ->getMock();
         $this->stock = new Stock(
             $this->storeManagerMock,
             $this->scopeConfigMock,
             $this->statusFactoryMock,
-            $this->stockRegistryProviderMock,
-            $this->stockResolverMock
+            $this->stockRegistryProviderMock
         );
     }
 
     public function testAssignStatusToProduct()
     {
-        $websiteId = 0;
-        $productId = 2;
-        $stockId = 3;
-        $status = 1;
+        $websiteId = 1;
+        $status = 'test';
 
         $stockStatusMock = $this->getMockBuilder('Magento\CatalogInventory\Api\Data\StockStatusInterface')
             ->disableOriginalConstructor()
@@ -106,23 +93,15 @@ public function testAssignStatusToProduct()
         $productMock->expects($this->once())
             ->method('setIsSalable')
             ->with($status);
-        $productMock->expects($this->once())
-            ->method('getId')
-            ->willReturn($productId);
-        $this->stockResolverMock->expects($this->once())
-            ->method('getStockId')
-            ->with($productId, $websiteId)
-            ->willReturn($stockId);
         $this->assertNull($this->stock->assignStatusToProduct($productMock));
     }
 
     public function testAddStockStatusToProducts()
     {
         $storeId = 1;
-        $websiteId = 0;
         $productId = 2;
-        $stockId = 3;
-        $status = 1;
+        $status = 'test';
+
         $productMock = $this->getMockBuilder('Magento\Catalog\Model\Product')
             ->disableOriginalConstructor()
             ->setMethods(['setIsSalable', 'getId'])
@@ -158,21 +137,14 @@ public function testAddStockStatusToProducts()
         $storeMock = $this->getMockBuilder('Magento\Store\Model\Store')
             ->disableOriginalConstructor()
             ->getMock();
-        $storeMock->expects($this->once())
-            ->method('getWebsiteId')
-            ->willReturn($websiteId);
         $this->storeManagerMock->expects($this->once())
             ->method('getStore')
-            ->with($storeId)
             ->willReturn($storeMock);
         $this->stockRegistryProviderMock->expects($this->once())
             ->method('getStockStatus')
             ->withAnyParameters()
             ->willReturn($stockStatusMock);
-        $this->stockResolverMock->expects($this->once())
-            ->method('getStockId')
-            ->with($productId, $websiteId)
-            ->willReturn($stockId);
+
         $this->assertNull($this->stock->addStockStatusToProducts($productCollectionMock));
     }
 
diff --git a/app/code/Magento/CatalogInventory/Test/Unit/Model/Spi/StockRegistryProviderTest.php b/app/code/Magento/CatalogInventory/Test/Unit/Model/Spi/StockRegistryProviderTest.php
index 5cf08ca76f3a3..8328208440b80 100644
--- a/app/code/Magento/CatalogInventory/Test/Unit/Model/Spi/StockRegistryProviderTest.php
+++ b/app/code/Magento/CatalogInventory/Test/Unit/Model/Spi/StockRegistryProviderTest.php
@@ -9,20 +9,45 @@
 
 /**
  * Class StockRegistryProviderTest
+ *
  * @SuppressWarnings(PHPMD.CouplingBetweenObjects)
+ * @SuppressWarnings(PHPMD.TooManyFields)
  */
 class StockRegistryProviderTest extends \PHPUnit_Framework_TestCase
 {
+    /** @var ObjectManagerHelper */
+    protected $objectManagerHelper;
+
     /**
      * @var \Magento\CatalogInventory\Model\Spi\StockRegistryProviderInterface|\PHPUnit_Framework_MockObject_MockObject
      */
     protected $stockRegistryProvider;
 
+    /**
+     * @var \Magento\CatalogInventory\Api\Data\StockInterface|\PHPUnit_Framework_MockObject_MockObject
+     */
+    protected $stock;
+
+    /**
+     * @var \Magento\CatalogInventory\Api\Data\StockItemInterface|\PHPUnit_Framework_MockObject_MockObject
+     */
+    protected $stockItem;
+
     /**
      * @var \Magento\CatalogInventory\Api\Data\StockStatusInterface|\PHPUnit_Framework_MockObject_MockObject
      */
     protected $stockStatus;
 
+    /**
+     * @var \Magento\CatalogInventory\Api\Data\StockStatusInterfaceFactory|\PHPUnit_Framework_MockObject_MockObject
+     */
+    protected $stockStatusFactory;
+
+    /**
+     * @var \Magento\CatalogInventory\Api\Data\StockItemInterfaceFactory|\PHPUnit_Framework_MockObject_MockObject
+     */
+    protected $stockItemFactory;
+
     /**
      * @var \Magento\CatalogInventory\Api\Data\StockInterfaceFactory|\PHPUnit_Framework_MockObject_MockObject
      */
@@ -58,6 +83,11 @@ class StockRegistryProviderTest extends \PHPUnit_Framework_TestCase
      */
     protected $stockStatusCriteriaFactory;
 
+    /**
+     * @var \Magento\CatalogInventory\Api\StockCriteriaInterface|\PHPUnit_Framework_MockObject_MockObject
+     */
+    protected $stockCriteria;
+
     /**
      * @var \Magento\CatalogInventory\Api\StockItemCriteriaInterface|\PHPUnit_Framework_MockObject_MockObject
      */
@@ -68,88 +98,132 @@ class StockRegistryProviderTest extends \PHPUnit_Framework_TestCase
      */
     protected $stockStatusCriteria;
 
-    /**
-     * @var \Magento\CatalogInventory\Api\StockConfigurationInterface|\PHPUnit_Framework_MockObject_MockObject
-     */
-    protected $stockConfiguration;
+    protected $productId = 111;
+    protected $productSku = 'simple';
+    protected $scopeId = 111;
 
     /**
-     * @var array
+     * @SuppressWarnings(PHPMD.ExcessiveMethodLength)
      */
-    protected $productData = [
-        'stock_id' => 111,
-        'product_id' => 112,
-        'product_sku' => 'simple',
-        'scope_id' => 113
-    ];
-
     protected function setUp()
     {
-        $objectManagerHelper = new ObjectManagerHelper($this);
+        $this->objectManagerHelper = new ObjectManagerHelper($this);
 
-        $this->stockFactory = $this->getMockBuilder('\Magento\CatalogInventory\Api\Data\StockInterfaceFactory')
-            ->disableOriginalConstructor()
-            ->setMethods(['create'])
-            ->getMock();
-        $stockItemFactory = $this->getMockBuilder('\Magento\CatalogInventory\Api\Data\StockItemInterfaceFactory')
-            ->disableOriginalConstructor()
-            ->setMethods(['create'])
-            ->getMock();
-        $stockStatusFactory = $this->getMockBuilder(
-            '\Magento\CatalogInventory\Api\Data\StockStatusInterfaceFactory'
-        )
-            ->disableOriginalConstructor()
-            ->setMethods(['create'])
-            ->getMock();
-        $stockStatusFactory->expects($this->any())->method('create')->willReturn($this->stockStatus);
-        $this->stockCriteriaFactory = $this->getMockBuilder(
-            'Magento\CatalogInventory\Api\StockCriteriaInterfaceFactory'
-        )
-            ->disableOriginalConstructor()
-            ->setMethods(['create'])
-            ->getMock();
-        $this->stockItemCriteriaFactory = $this->getMockBuilder(
-            'Magento\CatalogInventory\Api\StockItemCriteriaInterfaceFactory'
-        )
-            ->disableOriginalConstructor()
-            ->setMethods(['create'])
-            ->getMock();
-        $this->stockStatusCriteriaFactory = $this->getMockBuilder(
-            'Magento\CatalogInventory\Api\StockStatusCriteriaInterfaceFactory'
-        )
-            ->disableOriginalConstructor()
-            ->setMethods(['create'])
-            ->getMock();
+        $this->stock = $this->getMockForAbstractClass(
+            'Magento\CatalogInventory\Api\Data\StockInterface',
+            ['__wakeup', 'getStockId'],
+            '',
+            false
+        );
+        $this->stockItem = $this->getMockForAbstractClass(
+            'Magento\CatalogInventory\Api\Data\StockItemInterface',
+            ['__wakeup', 'getItemId'],
+            '',
+            false
+        );
+        $this->stockStatus = $this->getMockForAbstractClass(
+            'Magento\CatalogInventory\Api\Data\StockStatusInterface',
+            ['__wakeup', 'getProductId'],
+            '',
+            false
+        );
+
+        $this->stockFactory = $this->getMock(
+            '\Magento\CatalogInventory\Api\Data\StockInterfaceFactory',
+            ['create'],
+            [],
+            '',
+            false
+        );
+        $this->stockFactory->expects($this->any())->method('create')->willReturn($this->stock);
+
+        $this->stockItemFactory = $this->getMock(
+            '\Magento\CatalogInventory\Api\Data\StockItemInterfaceFactory',
+            ['create'],
+            [],
+            '',
+            false
+        );
+        $this->stockItemFactory->expects($this->any())->method('create')->willReturn($this->stockItem);
+
+        $this->stockStatusFactory = $this->getMock(
+            '\Magento\CatalogInventory\Api\Data\StockStatusInterfaceFactory',
+            ['create'],
+            [],
+            '',
+            false
+        );
+        $this->stockStatusFactory->expects($this->any())->method('create')->willReturn($this->stockStatus);
 
         $this->stockRepository = $this->getMockBuilder('\Magento\CatalogInventory\Api\StockRepositoryInterface')
             ->disableOriginalConstructor()
             ->getMock();
+
         $this->stockItemRepository = $this->getMockBuilder('\Magento\CatalogInventory\Api\StockItemRepositoryInterface')
             ->disableOriginalConstructor()
             ->getMock();
+
         $this->stockStatusRepository = $this->getMockBuilder(
             '\Magento\CatalogInventory\Api\StockStatusRepositoryInterface'
         )
             ->disableOriginalConstructor()
             ->getMock();
-        $this->stockConfiguration = $this->getMockBuilder('Magento\CatalogInventory\Api\StockConfigurationInterface')
-            ->disableOriginalConstructor()
-            ->setMethods(['getDefaultScopeId'])
-            ->getMockForAbstractClass();
 
-        $this->stockRegistryProvider = $objectManagerHelper->getObject(
+        $this->stockCriteriaFactory = $this->getMock(
+            'Magento\CatalogInventory\Api\StockCriteriaInterfaceFactory',
+            ['create'],
+            [],
+            '',
+            false
+        );
+        $this->stockCriteria = $this->getMockForAbstractClass(
+            'Magento\CatalogInventory\Api\StockCriteriaInterface',
+            ['setScopeFilter'],
+            '',
+            false
+        );
+
+        $this->stockItemCriteriaFactory = $this->getMock(
+            'Magento\CatalogInventory\Api\StockItemCriteriaInterfaceFactory',
+            ['create'],
+            [],
+            '',
+            false
+        );
+        $this->stockItemCriteria = $this->getMockForAbstractClass(
+            'Magento\CatalogInventory\Api\StockItemCriteriaInterface',
+            ['setProductsFilter', 'setScopeFilter'],
+            '',
+            false
+        );
+
+        $this->stockStatusCriteriaFactory = $this->getMock(
+            'Magento\CatalogInventory\Api\StockStatusCriteriaInterfaceFactory',
+            ['create'],
+            [],
+            '',
+            false
+        );
+        $this->stockStatusCriteria = $this->getMockForAbstractClass(
+            'Magento\CatalogInventory\Api\StockStatusCriteriaInterface',
+            ['setProductsFilter', 'setScopeFilter'],
+            '',
+            false
+        );
+
+        $this->stockRegistryProvider = $this->objectManagerHelper->getObject(
             '\Magento\CatalogInventory\Model\StockRegistryProvider',
             [
                 'stockRepository' => $this->stockRepository,
                 'stockFactory' => $this->stockFactory,
                 'stockItemRepository' => $this->stockItemRepository,
-                'stockItemFactory' => $stockItemFactory,
+                'stockItemFactory' => $this->stockItemFactory,
                 'stockStatusRepository' => $this->stockStatusRepository,
-                'stockStatusFactory' => $stockStatusFactory,
+                'stockStatusFactory' => $this->stockStatusFactory,
+
                 'stockCriteriaFactory' => $this->stockCriteriaFactory,
                 'stockItemCriteriaFactory' => $this->stockItemCriteriaFactory,
-                'stockStatusCriteriaFactory' => $this->stockStatusCriteriaFactory,
-                'stockConfiguration' => $this->stockConfiguration
+                'stockStatusCriteriaFactory' => $this->stockStatusCriteriaFactory
             ]
         );
     }
@@ -159,114 +233,63 @@ protected function tearDown()
         $this->stockRegistryProvider = null;
     }
 
-    public function testGetStockWithStock()
+    public function testGetStock()
     {
-        $stock = $this->getMockBuilder('Magento\CatalogInventory\Api\Data\StockInterface')
-            ->disableOriginalConstructor()
-            ->setMethods(['getStockId'])
-            ->getMockForAbstractClass();
-        $this->stockFactory->expects($this->any())->method('create')->willReturn($stock);
-        $stock->expects($this->once())->method('getStockId')->willReturn($this->productData['stock_id']);
-        $this->stockRepository->expects($this->once())->method('get')->willReturn($stock);
-        $this->assertEquals($stock, $this->stockRegistryProvider->getStock($this->productData['stock_id']));
-    }
-
-    public function testGetStockWithoutStock()
-    {
-        $this->stockConfiguration->expects($this->once())->method('getDefaultScopeId')
-            ->willReturn($this->productData['scope_id']);
-        $stock = $this->getMockBuilder('Magento\CatalogInventory\Api\Data\StockInterface')
-            ->disableOriginalConstructor()
-            ->setMethods(['getStockId'])
-            ->getMockForAbstractClass();
-        $stock->expects($this->once())->method('getStockId')->willReturn($this->productData['stock_id']);
-        $stockCollection = $this->getMockBuilder('Magento\CatalogInventory\Api\Data\StockCollectionInterface')
-            ->disableOriginalConstructor()
-            ->setMethods(['getItems'])
-            ->getMockForAbstractClass();
-        $stockCriteria = $this->getMockBuilder('\Magento\CatalogInventory\Api\StockCriteriaInterface')
-            ->disableOriginalConstructor()
-            ->setMethods(['getItems'])
-            ->getMockForAbstractClass();
-        $stockCriteria->expects($this->once())->method('setScopeFilter')->with($this->productData['scope_id'])
-            ->willReturnSelf();
-        $this->stockCriteriaFactory->expects($this->once())->method('create')->willReturn($stockCriteria);
-        $this->stockRepository->expects($this->once())->method('getList')
-            ->with($stockCriteria)->willReturn($stockCollection);
-        $stockCollection->expects($this->once())->method('getItems')->willReturn([$stock]);
-        $this->assertEquals($stock, $this->stockRegistryProvider->getStock(null));
+        $this->stockCriteriaFactory->expects($this->once())->method('create')->willReturn($this->stockCriteria);
+        $this->stockCriteria->expects($this->once())->method('setScopeFilter')->willReturn(null);
+        $stockCollection = $this->getMock(
+            '\Magento\CatalogInventory\Model\ResourceModel\Stock\Collection',
+            ['getFirstItem', '__wakeup', 'getItems'],
+            [],
+            '',
+            false
+        );
+        $stockCollection->expects($this->once())->method('getItems')->willReturn([$this->stock]);
+        $this->stockRepository->expects($this->once())->method('getList')->willReturn($stockCollection);
+        $this->stock->expects($this->once())->method('getStockId')->willReturn(true);
+        $this->assertEquals($this->stock, $this->stockRegistryProvider->getStock($this->scopeId));
     }
 
     public function testGetStockItem()
     {
-        $stock = $this->getMockBuilder('Magento\CatalogInventory\Api\Data\StockInterface')
-            ->disableOriginalConstructor()
-            ->setMethods(['getStockId'])
-            ->getMockForAbstractClass();
-        $this->stockRepository->expects($this->once())->method('get')->willReturn($stock);
-        $stockItemCriteria = $this->getMockBuilder('Magento\CatalogInventory\Api\StockItemCriteriaInterface')
-            ->disableOriginalConstructor()
-            ->setMethods(['setProductsFilter', 'setStockFilter'])
-            ->getMockForAbstractClass();
-        $this->stockItemCriteriaFactory->expects($this->once())->method('create')->willReturn($stockItemCriteria);
-        $stockItemCriteria->expects($this->once())->method('setProductsFilter')->with($this->productData['product_id'])
-            ->willReturnSelf();
-        $stock->expects($this->once())->method('getStockId')->willReturn($this->productData['stock_id']);
-        $stockItemCriteria->expects($this->once())->method('setStockFilter')->with($stock)
-            ->willReturnSelf();
-        $stockItemCollection = $this->getMockBuilder(
-            '\Magento\CatalogInventory\Model\ResourceModel\Stock\Item\Collection'
-        )
-            ->disableOriginalConstructor()
-            ->setMethods(['getFirstItem', 'getItems'])
-            ->getMock();
-        $stockItem = $this->getMockBuilder('Magento\CatalogInventory\Api\Data\StockItemInterface')
-            ->disableOriginalConstructor()
-            ->setMethods(['getItemId'])
-            ->getMockForAbstractClass();
-        $stockItemCollection->expects($this->once())->method('getItems')->willReturn([$stockItem]);
+        $this->stockItemCriteriaFactory->expects($this->once())->method('create')->willReturn($this->stockItemCriteria);
+        $this->stockItemCriteria->expects($this->once())->method('setProductsFilter')->willReturn(null);
+        $stockItemCollection = $this->getMock(
+            '\Magento\CatalogInventory\Model\ResourceModel\Stock\Item\Collection',
+            ['getFirstItem', '__wakeup', 'getItems'],
+            [],
+            '',
+            false
+        );
+        $stockItemCollection->expects($this->once())->method('getItems')->willReturn([$this->stockItem]);
         $this->stockItemRepository->expects($this->once())->method('getList')->willReturn($stockItemCollection);
-        $stockItem->expects($this->once())->method('getItemId')->willReturn(true);
+        $this->stockItem->expects($this->once())->method('getItemId')->willReturn(true);
         $this->assertEquals(
-            $stockItem,
-            $this->stockRegistryProvider->getStockItem($this->productData['product_id'], $this->productData['stock_id'])
+            $this->stockItem,
+            $this->stockRegistryProvider->getStockItem($this->productId, $this->scopeId)
         );
     }
 
     public function testGetStockStatus()
     {
-        $stockStatusCriteria = $this->getMockBuilder('Magento\CatalogInventory\Api\StockStatusCriteriaInterface')
-            ->disableOriginalConstructor()
-            ->setMethods(['setProductsFilter', 'addFilter'])
-            ->getMockForAbstractClass();
         $this->stockStatusCriteriaFactory->expects($this->once())
             ->method('create')
-            ->willReturn($stockStatusCriteria);
-        $stockStatusCriteria->expects($this->once())->method('setProductsFilter')
-            ->with($this->productData['product_id'])
-            ->willReturnSelf();
-        $stockStatusCriteria->expects($this->once())->method('addFilter')
-            ->with('stock', 'stock_id', $this->productData['stock_id'])
-            ->willReturnSelf();
-        $stockStatusCollection = $this->getMockBuilder(
-            '\Magento\CatalogInventory\Model\ResourceModel\Stock\Status\Collection'
-        )
-            ->disableOriginalConstructor()
-            ->setMethods(['getFirstItem', 'getItems'])
-            ->getMock();
-        $stockStatus = $this->getMockBuilder('Magento\CatalogInventory\Api\Data\StockStatusInterface')
-            ->disableOriginalConstructor()
-            ->setMethods(['getProductId'])
-            ->getMockForAbstractClass();
-        $stockStatusCollection->expects($this->once())->method('getItems')->willReturn([$stockStatus]);
-        $stockStatus->expects($this->once())->method('getProductId')->willReturn($this->productData['product_id']);
+            ->willReturn($this->stockStatusCriteria);
+        $this->stockStatusCriteria->expects($this->once())->method('setScopeFilter')->willReturn(null);
+        $this->stockStatusCriteria->expects($this->once())->method('setProductsFilter')->willReturn(null);
+        $stockStatusCollection = $this->getMock(
+            '\Magento\CatalogInventory\Model\ResourceModel\Stock\Status\Collection',
+            ['getFirstItem', '__wakeup', 'getItems'],
+            [],
+            '',
+            false
+        );
+        $stockStatusCollection->expects($this->once())->method('getItems')->willReturn([$this->stockStatus]);
         $this->stockStatusRepository->expects($this->once())->method('getList')->willReturn($stockStatusCollection);
+        $this->stockStatus->expects($this->once())->method('getProductId')->willReturn($this->productId);
         $this->assertEquals(
-            $stockStatus,
-            $this->stockRegistryProvider->getStockStatus(
-                $this->productData['product_id'],
-                $this->productData['stock_id']
-            )
+            $this->stockStatus,
+            $this->stockRegistryProvider->getStockStatus($this->productId, $this->scopeId)
         );
     }
 }
diff --git a/app/code/Magento/CatalogInventory/Test/Unit/Model/Stock/ItemTest.php b/app/code/Magento/CatalogInventory/Test/Unit/Model/Stock/ItemTest.php
index a81f930ccb6ce..27188a0efd352 100644
--- a/app/code/Magento/CatalogInventory/Test/Unit/Model/Stock/ItemTest.php
+++ b/app/code/Magento/CatalogInventory/Test/Unit/Model/Stock/ItemTest.php
@@ -63,9 +63,9 @@ class ItemTest extends \PHPUnit_Framework_TestCase
     protected $resource;
 
     /**
-     * @var \Magento\CatalogInventory\Api\StockRegistryInterface|\PHPUnit_Framework_MockObject_MockObject
+     * @var \Magento\CatalogInventory\Model\ResourceModel\Stock\Item\Collection|\PHPUnit_Framework_MockObject_MockObject
      */
-    protected $stockRegistry;
+    protected $resourceCollection;
 
     /**
      * @var int
@@ -117,8 +117,13 @@ protected function setUp()
             false
         );
 
-        $this->stockRegistry = $this->getMockBuilder('Magento\CatalogInventory\Api\StockRegistryInterface')
-            ->getMockForAbstractClass();
+        $this->resourceCollection = $this->getMock(
+            'Magento\CatalogInventory\Model\ResourceModel\Stock\Item\Collection',
+            [],
+            [],
+            '',
+            false
+        );
 
         $this->objectManagerHelper = new ObjectManagerHelper($this);
 
@@ -132,7 +137,7 @@ protected function setUp()
                 'stockConfiguration' => $this->stockConfiguration,
                 'stockItemRepository' => $this->stockItemRepository,
                 'resource' => $this->resource,
-                'stockRegistry' => $this->stockRegistry
+                'stockItemRegistry' => $this->resourceCollection
             ]
         );
     }
@@ -452,14 +457,4 @@ public function getQtyIncrementsDataProvider()
             ],
         ];
     }
-
-    public function testGetStockId()
-    {
-        $stockId = 1;
-        $stock = $this->getMockBuilder('Magento\CatalogInventory\Api\Data\StockInterface')
-            ->getMockForAbstractClass();
-        $this->stockRegistry->expects($this->once())->method('getStock')->willReturn($stock);
-        $stock->expects($this->once())->method('getStockId')->willReturn($stockId);
-        $this->assertEquals($stockId, $this->item->getStockId());
-    }
 }
diff --git a/app/code/Magento/CatalogInventory/Test/Unit/Observer/SaveInventoryDataObserverTest.php b/app/code/Magento/CatalogInventory/Test/Unit/Observer/SaveInventoryDataObserverTest.php
index 17ca09b6e24fd..96604e75d9294 100644
--- a/app/code/Magento/CatalogInventory/Test/Unit/Observer/SaveInventoryDataObserverTest.php
+++ b/app/code/Magento/CatalogInventory/Test/Unit/Observer/SaveInventoryDataObserverTest.php
@@ -19,26 +19,6 @@ class SaveInventoryDataObserverTest extends \PHPUnit_Framework_TestCase
      */
     protected $stockIndex;
 
-    /**
-     * @var \Magento\CatalogInventory\Api\StockConfigurationInterface|\PHPUnit_Framework_MockObject_MockObject
-     */
-    protected $stockConfiguration;
-
-    /**
-     * @var \Magento\CatalogInventory\Model\Spi\stockResolverInterface|\PHPUnit_Framework_MockObject_MockObject
-     */
-    protected $stockResolver;
-
-    /**
-     * @var \Magento\CatalogInventory\Api\StockRegistryInterface|\PHPUnit_Framework_MockObject_MockObject
-     */
-    protected $stockRegistry;
-
-    /**
-     * @var \Magento\CatalogInventory\Api\StockItemRepositoryInterface|\PHPUnit_Framework_MockObject_MockObject
-     */
-    protected $stockItemRepository;
-
     /**
      * @var \Magento\Framework\Event|\PHPUnit_Framework_MockObject_MockObject
      */
@@ -51,30 +31,12 @@ class SaveInventoryDataObserverTest extends \PHPUnit_Framework_TestCase
 
     protected function setUp()
     {
-        $this->stockIndex = $this->getMockBuilder('Magento\CatalogInventory\Api\StockIndexInterface')
-            ->disableOriginalConstructor()
-            ->setMethods(['rebuild'])
-            ->getMockForAbstractClass();
-
-        $this->stockConfiguration = $this->getMockBuilder('Magento\CatalogInventory\Api\StockConfigurationInterface')
-            ->disableOriginalConstructor()
-            ->setMethods(['getDefaultScopeId'])
-            ->getMockForAbstractClass();
-
-        $this->stockResolver = $this->getMockBuilder('Magento\CatalogInventory\Model\Spi\StockResolverInterface')
-            ->disableOriginalConstructor()
-            ->setMethods(['getStockId'])
-            ->getMockForAbstractClass();
-
-        $this->stockRegistry = $this->getMockBuilder('Magento\CatalogInventory\Api\StockRegistryInterface')
-            ->disableOriginalConstructor()
-            ->setMethods(['getStockItem'])
-            ->getMockForAbstractClass();
-
-        $this->stockItemRepository = $this->getMockBuilder('Magento\CatalogInventory\Api\StockItemRepositoryInterface')
-            ->disableOriginalConstructor()
-            ->setMethods(['save'])
-            ->getMockForAbstractClass();
+        $this->stockIndex = $this->getMockForAbstractClass(
+            'Magento\CatalogInventory\Api\StockIndexInterface',
+            ['rebuild'],
+            '',
+            false
+        );
 
         $this->event = $this->getMockBuilder('Magento\Framework\Event')
             ->disableOriginalConstructor()
@@ -94,15 +56,11 @@ protected function setUp()
             'Magento\CatalogInventory\Observer\SaveInventoryDataObserver',
             [
                 'stockIndex' => $this->stockIndex,
-                'stockConfiguration' => $this->stockConfiguration,
-                'stockResolver' => $this->stockResolver,
-                'stockRegistry' => $this->stockRegistry,
-                'stockItemRepository' => $this->stockItemRepository
             ]
         );
     }
 
-    public function testSaveInventoryDataWithoutStockData()
+    public function testSaveInventoryData()
     {
         $productId = 4;
         $websiteId = 5;
@@ -134,49 +92,4 @@ public function testSaveInventoryDataWithoutStockData()
 
         $this->observer->execute($this->eventObserver);
     }
-
-    public function testSaveInventoryDataWithStockData()
-    {
-        $stockItemData = [
-            'qty' => 4,
-            'product_id' => 2,
-            'website_id' => 3,
-            'stock_id' => 1,
-            'qty_correction' => -1
-        ];
-
-        $product = $this->getMock(
-            'Magento\Catalog\Model\Product',
-            ['getStockData', 'getId', 'getData'],
-            [],
-            '',
-            false
-        );
-        $product->expects($this->exactly(2))->method('getStockData')->will($this->returnValue(
-            ['qty' => $stockItemData['qty']]
-        ));
-        $product->expects($this->once())->method('getId')->will($this->returnValue($stockItemData['product_id']));
-        $product->expects($this->any())->method('getData')->willReturnMap(
-            [
-                ['stock_data/original_inventory_qty', null, $stockItemData['qty']+1]
-            ]
-        );
-        $this->stockConfiguration->expects($this->once())->method('getDefaultScopeId')
-            ->willReturn($stockItemData['website_id']);
-        $this->stockResolver->expects($this->once())->method('getStockId')
-            ->with($stockItemData['product_id'], $stockItemData['website_id'])
-            ->willReturn($stockItemData['stock_id']);
-        $stockItem = $this->getMockBuilder('\Magento\CatalogInventory\Api\Data\StockItemInterface')
-            ->disableOriginalConstructor()
-            ->setMethods(['addData'])
-            ->getMockForAbstractClass();
-        $this->stockRegistry->expects($this->once())->method('getStockItem')
-            ->with($stockItemData['product_id'], $stockItemData['website_id'])
-            ->willReturn($stockItem);
-        $stockItem->expects($this->once())->method('addData')->with($stockItemData)->willReturnSelf();
-        $this->stockItemRepository->expects($this->once())->method('save')->with($stockItem);
-        $this->event->expects($this->once())->method('getProduct')->will($this->returnValue($product));
-
-        $this->observer->execute($this->eventObserver);
-    }
 }
diff --git a/app/code/Magento/CatalogInventory/etc/di.xml b/app/code/Magento/CatalogInventory/etc/di.xml
index 40f9bf2d1275d..fbce94514ebff 100644
--- a/app/code/Magento/CatalogInventory/etc/di.xml
+++ b/app/code/Magento/CatalogInventory/etc/di.xml
@@ -30,8 +30,7 @@
 
     <preference for="Magento\CatalogInventory\Model\Spi\StockRegistryProviderInterface" type="Magento\CatalogInventory\Model\StockRegistryProvider" />
     <preference for="Magento\CatalogInventory\Model\Spi\StockStateProviderInterface" type="Magento\CatalogInventory\Model\StockStateProvider" />
-    <preference for="Magento\CatalogInventory\Model\Spi\StockResolverInterface" type="Magento\CatalogInventory\Model\StockResolver" />
-
+    
     <preference for="Magento\CatalogInventory\Model\ResourceModel\QtyCounterInterface" type="\Magento\CatalogInventory\Model\ResourceModel\Stock" />
     <type name="Magento\Catalog\Model\Product\Attribute\Repository">
         <plugin name="filterCustomAttribute" type="Magento\CatalogInventory\Model\Plugin\FilterCustomAttribute" />