diff --git a/app/repository/collection-index-repository.js b/app/repository/collection-index-repository.js
index 84eaaf6b..d9e99971 100644
--- a/app/repository/collection-index-repository.js
+++ b/app/repository/collection-index-repository.js
@@ -1,3 +1,4 @@
+const { BadlyFormattedParameterError, MissingParameterError } = require('../exceptions');
 const CollectionIndex = require('../models/collection-index-model');
 class CollectionIndexRepository {
 
@@ -5,5 +6,33 @@ class CollectionIndexRepository {
         this.model = model;
     }
 
+    async retrieveAll(options) {
+        const collectionIndexes = await this.model.find()
+            .skip(options.offset)
+            .limit(options.limit)
+            .lean()
+            .exec();
+
+        return collectionIndexes;
+    }
+
+    async retrieveById(id) {
+        try {
+            if (!id) {
+                throw new MissingParameterError('id');
+            }
+    
+            const collectionIndex = await this.model.findOne({ "collection_index.id": id });
+    
+            return collectionIndex; // Note: collectionIndex is null if not found
+        } catch (err) {
+            if (err.name === 'CastError') {
+                throw new BadlyFormattedParameterError;
+            } else {
+                throw err;
+            }
+        }
+    }
+
 }
-module.exports = CollectionIndexRepository(CollectionIndex);
+module.exports = new CollectionIndexRepository(CollectionIndex);
diff --git a/app/services/collection-indexes-service.js b/app/services/collection-indexes-service.js
index 25bbe8d4..1b85b8a9 100644
--- a/app/services/collection-indexes-service.js
+++ b/app/services/collection-indexes-service.js
@@ -26,36 +26,12 @@ class CollectionIndexService {
 
 
     async retrieveAll(options) {
-        const collectionIndexes = await CollectionIndex.find()
-            .skip(options.offset)
-            .limit(options.limit)
-            .lean()
-            .exec();
-
-        return collectionIndexes;
+        return await this.repository.retrieveAll(options);
     }
     
 
     async retrieveById(id) {
-        try {
-            if (!id) {
-                const error = new Error(this.errors.missingParameter);
-                error.parameterName = 'id';
-                throw error;
-            }
-    
-            const collectionIndex = await CollectionIndex.findOne({ "collection_index.id": id });
-    
-            return collectionIndex; // Note: collectionIndex is null if not found
-        } catch (err) {
-            if (err.name === 'CastError') {
-                const error = new Error(this.errors.badlyFormattedParameter);
-                error.parameterName = 'id';
-                throw error;
-            } else {
-                throw err;
-            }
-        }
+        return await this.repository.retrieveById(id);
     }