diff --git a/pyinsights/log_skeleton/log_skeleton.py b/pyinsights/log_skeleton/log_skeleton.py
index d0ecb9a..83a1425 100644
--- a/pyinsights/log_skeleton/log_skeleton.py
+++ b/pyinsights/log_skeleton/log_skeleton.py
@@ -214,6 +214,8 @@ def _get_always_after(self, noise_threshold, case_id=None):
             query.add(self._get_case_id_filter(case_id))
 
         df = datamodel.get_data_frame(query)
+
+        num_cases = df[case_col].nunique()
         # group by activity
         grouped = df.groupby(by=[act_col], axis=0)
         # get groups as dict