diff --git a/analytics/analytics/utils/common.py b/analytics/analytics/utils/common.py
index a0ae298..39bd8f5 100644
--- a/analytics/analytics/utils/common.py
+++ b/analytics/analytics/utils/common.py
@@ -133,12 +133,10 @@ def best_pattern(pattern_list: list, data: pd.Series, dir: str) -> list:
     return new_pattern_list
 
 def find_nan_indexes(segment: pd.Series) -> list:
-    nan_list = np.isnan(segment)
-    nan_indexes = []
-    for i, val in enumerate(nan_list):
-        if val:
-            nan_indexes.append(i)
-    return nan_indexes
+    nan_list = pd.isnull(segment)
+    nan_list = np.array(nan_list)
+    nan_indexes = np.where(nan_list == True)[0]
+    return list(nan_indexes)
 
 def check_nan_values(segment: Union[pd.Series, list]) -> Union[pd.Series, list]:
     nan_list = utils.find_nan_indexes(segment)
diff --git a/analytics/tests/test_utils.py b/analytics/tests/test_utils.py
index 17d9a3f..ed4cceb 100644
--- a/analytics/tests/test_utils.py
+++ b/analytics/tests/test_utils.py
@@ -219,6 +219,23 @@ class TestUtils(unittest.TestCase):
             utils.get_av_model(patterns_list)
         except ValueError:
             self.fail('Method get_convolve raised unexpectedly')
+    
+    def test_find_nan_indexes(self):
+        data = [1, 1, 1, 0, 0, np.NaN, None, []]
+        data = pd.Series(data)
+        result = [5, 6]
+        self.assertEqual(utils.find_nan_indexes(data), result)
+    
+    def test_find_nan_indexes_normal_values(self):
+        data = [1, 1, 1, 0, 0, 0, 1, 1]
+        data = pd.Series(data)
+        result = []
+        self.assertEqual(utils.find_nan_indexes(data), result)
+    
+    def test_find_nan_indexes_empty_values(self):
+        data = []
+        result = []
+        self.assertEqual(utils.find_nan_indexes(data), result)
 
 if __name__ == '__main__':
     unittest.main()