diff --git a/src/SymptomsCausedByVaccines/MultiLineFitting/ClustersFactory.py b/src/SymptomsCausedByVaccines/MultiLineFitting/ClustersFactory.py
index d524ba443ec..ddb633a20ef 100644
--- a/src/SymptomsCausedByVaccines/MultiLineFitting/ClustersFactory.py
+++ b/src/SymptomsCausedByVaccines/MultiLineFitting/ClustersFactory.py
@@ -31,7 +31,7 @@ class ClustersFactory:
                 preferenceMatrix[clusterIndexA] = np.logical_and(preferenceMatrix[clusterIndexA], preferenceMatrix[clusterIndexB])
                 preferenceMatrix = np.delete(preferenceMatrix, clusterIndexB, axis = 0)
 
-        return clusters
+        return clusters, preferenceMatrix
 
     @staticmethod
     def _createPreferenceMatrix(points, lines, consensusThreshold):
@@ -46,3 +46,7 @@ class ClustersFactory:
         intersection = np.count_nonzero(np.logical_and(setA, setB))
         union = np.count_nonzero(np.logical_or(setA, setB))
         return 1. * intersection / union
+
+    @staticmethod
+    def _getLineIndexes(preferenceMatrix):
+        return [list(lines).index(1) for lines in preferenceMatrix]
diff --git a/src/SymptomsCausedByVaccines/MultiLineFitting/ClustersFactoryTest.py b/src/SymptomsCausedByVaccines/MultiLineFitting/ClustersFactoryTest.py
index 51d2cc7cf8d..d6780902c78 100644
--- a/src/SymptomsCausedByVaccines/MultiLineFitting/ClustersFactoryTest.py
+++ b/src/SymptomsCausedByVaccines/MultiLineFitting/ClustersFactoryTest.py
@@ -1,7 +1,7 @@
 import unittest
 import numpy as np
 from skspatial.objects import Line
-from src.SymptomsCausedByVaccines.MultiLineFitting.ClustersFactory import ClustersFactory
+from SymptomsCausedByVaccines.MultiLineFitting.ClustersFactory import ClustersFactory
 
 
 class ClustersFactoryTest(unittest.TestCase):
@@ -55,7 +55,7 @@ class ClustersFactoryTest(unittest.TestCase):
                 ])
 
         # When
-        clusters = ClustersFactory.createClusters(preferenceMatrix)
+        clusters, _ = ClustersFactory.createClusters(preferenceMatrix)
 
         # Then
         np.testing.assert_array_equal(
@@ -77,7 +77,7 @@ class ClustersFactoryTest(unittest.TestCase):
                 ])
 
         # When
-        clusters = ClustersFactory.createClusters(preferenceMatrix)
+        clusters, _ = ClustersFactory.createClusters(preferenceMatrix)
 
         # Then
         np.testing.assert_array_equal(
@@ -87,3 +87,17 @@ class ClustersFactoryTest(unittest.TestCase):
                     [2, 1, 0],
                     [4, 3]
                 ]))
+
+    def test_getLineIndexes(self):
+        # Given
+        preferenceMatrix = np.array(
+                [
+                    [0, 0, 1],
+                    [0, 1, 1]
+                ])
+
+        # When
+        lineIndexes = ClustersFactory._getLineIndexes(preferenceMatrix)
+
+        # Then
+        np.testing.assert_array_equal(lineIndexes, [2, 1])