diff --git a/baro/anomaly_detection.py b/baro/anomaly_detection.py
index 58541a0..e704103 100644
--- a/baro/anomaly_detection.py
+++ b/baro/anomaly_detection.py
@@ -2,6 +2,7 @@
 warnings.filterwarnings("ignore")
 import pandas 
 import numpy as np
+from baro.utility import drop_constant, find_cps
 
 def nsigma(data, k=3, startsfrom=100):
     """For each time series (column) in the data,
@@ -50,12 +51,24 @@ def bocpd(data):
     from functools import partial
     from baro._bocpd import online_changepoint_detection, constant_hazard, MultivariateT
     data = data.copy()
-    time_col = data['time']
-    data.drop(columns=['time'], inplace=True)
+    
+    # select latency and error metrics from microservices
+    selected_cols = []
+    for c in data.columns:
+        if 'queue-master' in c or 'rabbitmq_' in c: continue
+        if "latency" in c or "latency-50" in c or "_error" in c:
+            selected_cols.append(c)
+    data = data[selected_cols]
+
+    # handle na
+    data = drop_constant(data)
+    data = data.fillna(method="ffill")
+    data = data.fillna(0)
     for c in data.columns:
         data[c] = (data[c] - np.min(data[c])) / (np.max(data[c]) - np.min(data[c]))
-    data = data.ffill()
+    data = data.fillna(method="ffill")
     data = data.fillna(0)
+        
     data = data.to_numpy()
 
     R, maxes = online_changepoint_detection(
@@ -63,15 +76,9 @@ def bocpd(data):
         partial(constant_hazard, 50),
         MultivariateT(dims=data.shape[1])
     )
-    Nw = 10
-    anomalies, merged_anomalies = find_anomalies(data=R[Nw,Nw:-1].tolist(), time_col=time_col)
-    return anomalies
-    
-
-def anomaly_detector(data, method="nsigma"):
-    # assert data is dataframe
-    assert isinstance(data, pandas.DataFrame)
-
-    # retain all `latency` and `error` columns
-    data = data[['latency', 'error']]
+    cps = find_cps(maxes)
+    anomalies = [p[0] for p in cps]
+    # anomalies, merged_anomalies = find_anomalies(data=R[Nw,Nw:-1].tolist(), time_col=time_col)
     
+    return anomalies
+    
\ No newline at end of file