diff --git a/CandyHouseSolution/CandyHouseTests/CandyHouseTests.csproj b/CandyHouseSolution/CandyHouseTests/CandyHouseTests.csproj
index c47af43..12447e8 100644
--- a/CandyHouseSolution/CandyHouseTests/CandyHouseTests.csproj
+++ b/CandyHouseSolution/CandyHouseTests/CandyHouseTests.csproj
@@ -102,8 +102,10 @@
     </ItemGroup>
     <ItemGroup>
         <Compile Include="DataModelsTests\CustomerDataModelTests.cs" />
+        <Compile Include="DataModelsTests\IngredientStockDataModelTests.cs" />
         <Compile Include="DataModelsTests\OrderDataModelTests.cs" />
         <Compile Include="DataModelsTests\ProductStockDataModelTests.cs" />
+        <Compile Include="DataModelsTests\SupplyItemDataModelTests.cs" />
     </ItemGroup>
     <ItemGroup>
       <None Include="App.config" />
diff --git a/CandyHouseSolution/CandyHouseTests/DataModelsTests/IngredientStockDataModelTests.cs b/CandyHouseSolution/CandyHouseTests/DataModelsTests/IngredientStockDataModelTests.cs
new file mode 100644
index 0000000..2012b3b
--- /dev/null
+++ b/CandyHouseSolution/CandyHouseTests/DataModelsTests/IngredientStockDataModelTests.cs
@@ -0,0 +1,40 @@
+using System;
+using NUnit.Framework;
+using CandyHouseBase.DataModels;
+using CandyHouseBase.Exceptions;
+
+namespace CandyHouseTests.DataModelsTests
+{
+    [TestFixture]
+    public class IngredientStockDataModelTests
+    {
+        [Test]
+        public void IngredientStock_ShouldThrowException_WhenIdIsInvalid()
+        {
+            var stock = new IngredientStockDataModel("", 10);
+            Assert.Throws<ValidationException>(stock.Validate);
+        }
+
+        [Test]
+        public void IngredientStock_ShouldThrowException_WhenQuantityIsNegative()
+        {
+            var stock = new IngredientStockDataModel(Guid.NewGuid().ToString(), -5);
+            Assert.Throws<ValidationException>(stock.Validate);
+        }
+
+        [Test]
+        public void IngredientStock_ShouldAddStockCorrectly()
+        {
+            var stock = new IngredientStockDataModel(Guid.NewGuid().ToString(), 10);
+            stock.AddStock(5);
+            Assert.That(stock.Quantity, Is.EqualTo(15));
+        }
+
+        [Test]
+        public void IngredientStock_ShouldThrowException_WhenRemovingTooMuchStock()
+        {
+            var stock = new IngredientStockDataModel(Guid.NewGuid().ToString(), 10);
+            Assert.Throws<ValidationException>(() => stock.RemoveStock(15));
+        }
+    }
+}
\ No newline at end of file
diff --git a/CandyHouseSolution/CandyHouseTests/DataModelsTests/SupplyItemDataModelTests.cs b/CandyHouseSolution/CandyHouseTests/DataModelsTests/SupplyItemDataModelTests.cs
new file mode 100644
index 0000000..53a843c
--- /dev/null
+++ b/CandyHouseSolution/CandyHouseTests/DataModelsTests/SupplyItemDataModelTests.cs
@@ -0,0 +1,43 @@
+using System;
+using NUnit.Framework;
+using CandyHouseBase.DataModels;
+using CandyHouseBase.Enums;
+using CandyHouseBase.Exceptions;
+
+namespace CandyHouseTests.DataModelsTests
+{
+    [TestFixture]
+    public class SupplyItemDataModelTests
+    {
+        [Test]
+        public void SupplyItem_ShouldThrowException_WhenSupplyIdIsInvalid()
+        {
+            var supplyItem = new SupplyItemDataModel("", Guid.NewGuid().ToString(), 10, ItemType.Ingredient);
+            Assert.Throws<ValidationException>(supplyItem.Validate);
+        }
+
+        [Test]
+        public void SupplyItem_ShouldThrowException_WhenItemIdIsInvalid()
+        {
+            var supplyItem = new SupplyItemDataModel(Guid.NewGuid().ToString(), "", 10, ItemType.Product);
+            Assert.Throws<ValidationException>(supplyItem.Validate);
+        }
+
+        [Test]
+        public void SupplyItem_ShouldThrowException_WhenQuantityIsZeroOrNegative()
+        {
+            var supplyItem = new SupplyItemDataModel(Guid.NewGuid().ToString(), Guid.NewGuid().ToString(), 0,
+                ItemType.Product);
+            Assert.Throws<ValidationException>(supplyItem.Validate);
+        }
+
+        [Test]
+        public void SupplyItem_ShouldCreateSuccessfully_WithValidData()
+        {
+            var supplyItem = new SupplyItemDataModel(Guid.NewGuid().ToString(), Guid.NewGuid().ToString(), 10,
+                ItemType.Ingredient);
+            Assert.That(supplyItem.Quantity, Is.EqualTo(10));
+            Assert.That(supplyItem.ItemType, Is.EqualTo(ItemType.Ingredient));
+        }
+    }
+}
\ No newline at end of file