feat: Implement reliability-based CM cost prediction using historical cost per failure and document the new prediction logic.

src/modules/equipment/Prediksi.py

@@ -674,6 +674,39 @@ class Prediksi:
                 print(f"HTTP error occurred: {e}")
                 return {}
 
+    def __get_historical_cost_per_failure(self, assetnum):
+        connection = None
+        try:
+            connection = get_production_connection()
+            if connection is None:
+                return 0.0
+            cursor = connection.cursor()
+            # Optimized single-pass query: counts and sums in one scan
+            query = """
+            SELECT 
+                SUM(a.actmatcost) / NULLIF(COUNT(CASE WHEN a.wonum NOT LIKE 'T%%' THEN 1 END), 0) as cost_failure
+            FROM wo_maximo a
+            WHERE (a.asset_unit = '3' OR a.asset_unit = '00')
+              AND a.status IN ('COMP', 'CLOSE')
+              AND a.asset_assetnum = %s
+              AND a.worktype IN ('CM', 'PROACTIVE', 'EM')
+              AND a.wojp8 != 'S1'
+              AND (
+                  a.description NOT ILIKE '%%U4%%'
+                  OR (a.description ILIKE '%%U3%%' AND a.description ILIKE '%%U4%%')
+              )
+            """
+            cursor.execute(query, (assetnum,))
+            result = cursor.fetchone()
+            cost_failure = float(result[0]) if result and result[0] is not None else 0.0
+            return cost_failure
+        except Exception as e:
+            print(f"Error fetching historical cost per failure for {assetnum}: {e}")
+            return 0.0
+        finally:
+            if connection:
+                connection.close()
+
     def __get_man_hour_rate(self, staff_level: str = "Junior"):
         connection = None
         try:
@@ -755,7 +788,8 @@ class Prediksi:
             rate, max_year = self.__get_rate_and_max_year(assetnum)
             man_hour_rate = self.__get_man_hour_rate() # Defaults to 'junior'
 
-            pmt = 0
+            # Pre-fetch cost per failure once per asset to avoid redundant DB queries
+            avg_cost_per_failure = self.__get_historical_cost_per_failure(assetnum)
 
             # Prediksi untuk setiap kolom
             for column in df.columns:
@@ -807,16 +841,32 @@ class Prediksi:
                                 preds_list.append(cost)
                             preds = np.array(preds_list, dtype=float)
 
-                        elif recent_vals.empty:
-                            avg = 0.0
-                            preds = np.repeat(float(avg), n_future)
                         else:
-                            avg = pd.to_numeric(recent_vals, errors="coerce").fillna(0).mean()
-                            avg = 0.0 if pd.isna(avg) else float(avg)
-                            preds = np.repeat(float(avg), n_future)
+                            # Use pre-fetched cost per failure
+                            preds_list = []
+                            for yr in future_years:
+                                failures_data = await self._fetch_api_data(assetnum, yr)
+                                # Interval from predicted number of failures
+                                interval = 0.0
+                                if isinstance(failures_data, dict):
+                                    data_list = failures_data.get("data")
+                                    if isinstance(data_list, list) and len(data_list) > 0:
+                                        first_item = data_list[0]
+                                        if isinstance(first_item, dict):
+                                            num_fail = first_item.get("num_fail")
+                                            if num_fail is not None:
+                                                try:
+                                                    interval = float(num_fail)
+                                                except Exception:
+                                                    interval = 0.0
+                                
+                                # predicted_cost = predicted_failures * avg_cost_per_failure
+                                cost = interval * avg_cost_per_failure
+                                preds_list.append(cost)
+                            preds = np.array(preds_list, dtype=float)
 
                     else:
-                        # Для kolom non-cm, gunakan nilai dari last actual year bila ada,
+                        # kolom non-cm, gunakan nilai dari last actual year bila ada,
                         # jika tidak ada gunakan last available non-NA value, jika tidak ada pakai 0.0
                         if "is_actual" in df.columns and not df[df["is_actual"] == 1].empty:
                             last_actual_year_series = df[df["is_actual"] == 1]["year"]

src/modules/equipment/formula.py

@@ -6,6 +6,14 @@ This file consolidates the core mathematical/financial formulas used across:
 - `insert_actual_data.py` (aggregation formulas, man-hour conversion)
 - `Prediksi.py` (future value / fv wrappers)
 
+### Prediction Logic Summary
+| Category | Logic Type | Formula Basis |
+| :--- | :--- | :--- |
+| **CM Labor** | **Reliability-Based** | `Failures x 3.0 x 1.0 x ManPowerRate` |
+| **CM Other** | **Reliability-Based** | `Failures x CostPerFailure (from Production SQL)` |
+| **PM / OH / PDM** | **Last Scenario** | `Value from Last Actual Year` (Carry Forward) |
+| **Total Risk Cost** | **Aggregated** | `Sum of above + Asset Criticality Multiplier` |
+
 Keep these functions pure and well-documented to make debugging and
 comparisons easier.
 """