diff --git a/packages/component-fixture-manager/src/fixtures/collections.js b/packages/component-fixture-manager/src/fixtures/collections.js
index 38495a9e8186e3403f127da38d414ca2c84cf6ef..0fbff658ca84fc9266a31674461679e769a1ff13 100644
--- a/packages/component-fixture-manager/src/fixtures/collections.js
+++ b/packages/component-fixture-manager/src/fixtures/collections.js
@@ -31,6 +31,7 @@ const collections = {
     fragments: [fragment.id],
     owners: [user.id],
     save: jest.fn(() => collections.collection),
+    getFragments: jest.fn(() => [fragment]),
     invitations: [
       {
         id: chance.guid(),
@@ -74,6 +75,7 @@ const collections = {
     fragments: [fragment.id],
     owners: [user.id],
     save: jest.fn(() => collections.collection),
+    getFragments: jest.fn(() => [fragment]),
     invitations: [
       {
         id: chance.guid(),
@@ -116,6 +118,7 @@ const collections = {
     fragments: [fragment1.id, noInvitesFragment.id],
     owners: [user.id],
     save: jest.fn(() => collections.collection2),
+    getFragments: jest.fn(() => [fragment1, noInvitesFragment]),
     invitations: [
       {
         id: chance.guid(),
@@ -160,6 +163,7 @@ const collections = {
     created: chance.timestamp(),
     customId: '0000001',
     fragments: [reviewCompletedFragment.id],
+    getFragments: jest.fn(() => [reviewCompletedFragment]),
     invitations: [
       {
         id: chance.guid(),
@@ -190,6 +194,7 @@ const collections = {
     fragments: [fragment.id, reviewCompletedFragment.id],
     owners: [user.id],
     save: jest.fn(() => collections.collection),
+    getFragments: jest.fn(() => [fragment, reviewCompletedFragment]),
     invitations: [
       {
         id: chance.guid(),
@@ -220,6 +225,7 @@ const collections = {
     fragments: [],
     owners: [user.id],
     save: jest.fn(() => collections.collection),
+    getFragments: jest.fn(() => []),
     customId: chance.natural({ min: 999999, max: 9999999 }),
   },
   noEditorRecomedationCollection: {
@@ -229,6 +235,7 @@ const collections = {
     fragments: [noEditorRecomedationFragment.id],
     owners: [user.id],
     save: jest.fn(() => collections.noEditorRecomedationCollection),
+    getFragments: jest.fn(() => [noEditorRecomedationFragment]),
     invitations: [
       {
         id: chance.guid(),
@@ -271,6 +278,7 @@ const collections = {
     fragments: [reviewCompletedFragment.id, noInvitesFragment.id],
     owners: [user.id],
     save: jest.fn(() => collections.collection),
+    getFragments: jest.fn(() => [reviewCompletedFragment, noInvitesFragment]),
     invitations: [
       {
         id: chance.guid(),
diff --git a/packages/component-helper-service/src/services/Collection.js b/packages/component-helper-service/src/services/Collection.js
index 90faee9ffa288e6fe165d678a578ad0f4a580819..5ead71c258d5cad06b646bd6b9639df96b59e42a 100644
--- a/packages/component-helper-service/src/services/Collection.js
+++ b/packages/component-helper-service/src/services/Collection.js
@@ -108,20 +108,8 @@ class Collection {
     return lastName || firstName
   }
 
-  async getAllCollectionFragments({ FragmentModel }) {
-    const allCollectionFragments = await Promise.all(
-      get(this.collection, 'fragments', []).map(async fragmentId => {
-        const fragment = await FragmentModel.find(fragmentId)
-        return fragment
-      }),
-    )
-    return allCollectionFragments
-  }
-
-  async getReviewerNumber({ userId, FragmentModel }) {
-    const allCollectionFragments = await this.getAllCollectionFragments({
-      FragmentModel,
-    })
+  async getReviewerNumber({ userId }) {
+    const allCollectionFragments = await this.collection.getFragments()
     const allCollectionInvitations = flatMap(
       allCollectionFragments,
       fragment => fragment.invitations,
diff --git a/packages/component-helper-service/src/tests/collection.test.js b/packages/component-helper-service/src/tests/collection.test.js
index 30315ad22e5616910b55751765a8d4b9723ba468..ebf35e9d666f30daf27cdce4c55c57f6637c3cf1 100644
--- a/packages/component-helper-service/src/tests/collection.test.js
+++ b/packages/component-helper-service/src/tests/collection.test.js
@@ -4,48 +4,13 @@ process.env.SUPPRESS_NO_CONFIG_WARNING = true
 const { cloneDeep } = require('lodash')
 const fixturesService = require('pubsweet-component-fixture-service')
 
-const { fixtures, Model } = fixturesService
+const { fixtures } = fixturesService
 const { Collection } = require('../Helper')
 
 describe('Collection helper', () => {
   let testFixtures = {}
-  let models
   beforeEach(() => {
     testFixtures = cloneDeep(fixtures)
-    models = Model.build(testFixtures)
-  })
-
-  describe('getAllCollectionFragments', () => {
-    it('should return an array with all collection fragments', async () => {
-      const { collection } = testFixtures.collections
-      const collectionHelper = new Collection({ collection })
-      const FragmentModel = models.Fragment
-
-      const numberOfFragments = collection.fragments.length
-      const allCollectionFragments = await collectionHelper.getAllCollectionFragments(
-        {
-          FragmentModel,
-        },
-      )
-
-      expect(allCollectionFragments).toHaveLength(numberOfFragments)
-      expect(typeof allCollectionFragments[0]).toBe('object')
-      expect(allCollectionFragments[0].type).toBe('fragment')
-    })
-    it('should return an empty array when no fragments exist', async () => {
-      const { noFragmentsCollection } = testFixtures.collections
-      const collectionHelper = new Collection({ noFragmentsCollection })
-      const FragmentModel = models.Fragment
-
-      const allCollectionFragments = await collectionHelper.getAllCollectionFragments(
-        {
-          FragmentModel,
-        },
-      )
-
-      expect(allCollectionFragments).toHaveLength(0)
-      expect(typeof allCollectionFragments[0]).toBe('undefined')
-    })
   })
 
   describe('getReviewerNumber', () => {
@@ -53,11 +18,9 @@ describe('Collection helper', () => {
       const { collection } = testFixtures.collections
       const { reviewer } = testFixtures.users
       const collectionHelper = new Collection({ collection })
-      const FragmentModel = models.Fragment
 
       const reviewerNumber = await collectionHelper.getReviewerNumber({
         userId: reviewer.id,
-        FragmentModel,
       })
 
       expect(reviewerNumber).toBe(1)
@@ -68,11 +31,9 @@ describe('Collection helper', () => {
       const collectionHelper = new Collection({
         collection: collectionReviewCompleted,
       })
-      const FragmentModel = models.Fragment
 
       const reviewerNumber = await collectionHelper.getReviewerNumber({
         userId: reviewer.id,
-        FragmentModel,
       })
 
       expect(reviewerNumber).toBe(3)
@@ -83,11 +44,9 @@ describe('Collection helper', () => {
       const collectionHelper = new Collection({
         collection: oneReviewedFragmentCollection,
       })
-      const FragmentModel = models.Fragment
 
       const reviewerNumber = await collectionHelper.getReviewerNumber({
         userId: answerReviewer.id,
-        FragmentModel,
       })
 
       expect(reviewerNumber).toBe(2)
@@ -98,11 +57,9 @@ describe('Collection helper', () => {
       const collectionHelper = new Collection({
         collection: oneReviewedFragmentCollection,
       })
-      const FragmentModel = models.Fragment
 
       const reviewerNumber = await collectionHelper.getReviewerNumber({
         userId: reviewer.id,
-        FragmentModel,
       })
 
       expect(reviewerNumber).toBe(3)
diff --git a/packages/component-manuscript-manager/src/routes/fragmentsRecommendations/patch.js b/packages/component-manuscript-manager/src/routes/fragmentsRecommendations/patch.js
index 7b03107b5f04aa5b56d17b9bab0b53dfbf41505b..a973956cfb0e01d956a74168bebe3e81a65b62ca 100644
--- a/packages/component-manuscript-manager/src/routes/fragmentsRecommendations/patch.js
+++ b/packages/component-manuscript-manager/src/routes/fragmentsRecommendations/patch.js
@@ -66,11 +66,10 @@ module.exports = models => async (req, res) => {
       }
 
       const collectionHelper = new Collection({ collection })
-      const FragmentModel = models.Fragment
       const reviewerNumber = await collectionHelper.getReviewerNumber({
         userId: req.authInfo.id,
-        FragmentModel,
       })
+
       find(fragment.invitations, [
         'userId',
         userId,