diff --git a/src/models/ItemAssociation.js b/src/models/ItemAssociation.js
new file mode 100644
index 0000000..e84cc94
--- /dev/null
+++ b/src/models/ItemAssociation.js
@@ -0,0 +1,27 @@
+const mongoose = require("mongoose");
+
+const schema = new mongoose.Schema(
+  {
+    item_id: {
+      type: mongoose.Schema.Types.ObjectId,
+      ref: "Item",
+    },
+    sub_level_id: {
+      type: mongoose.Schema.Types.ObjectId,
+      ref: "Sublevel",
+    },
+    quantity: {
+      type: Number,
+      default: 0,
+    },
+  },
+  {
+    timestamps: true,
+  }
+);
+
+schema.index({ item_id: 1, sub_level_id: 1 }, { unique: 1 });
+
+const ItemAssociation = mongoose.model("ItemAssociation", schema);
+
+module.exports = ItemAssociation;