diff --git a/addons/mrp/models/mrp_workorder.py b/addons/mrp/models/mrp_workorder.py
index bdb4f89f6d6..19765c80652 100644
--- a/addons/mrp/models/mrp_workorder.py
+++ b/addons/mrp/models/mrp_workorder.py
@@ -553,6 +553,13 @@ class MrpWorkorder(models.Model):
         vals['leave_id'] = leave.id
         self.write(vals)
 
+    def _cal_cost(self):
+        total = 0
+        for wo in self:
+            duration = sum(wo.time_ids.mapped('duration'))
+            total += (duration / 60.0) * wo.workcenter_id.costs_hour
+        return total
+
     @api.model
     def gantt_unavailability(self, start_date, end_date, scale, group_bys=None, rows=None):
         """Get unavailabilities data to display in the Gantt view."""
diff --git a/addons/mrp_account/models/mrp_production.py b/addons/mrp_account/models/mrp_production.py
index 4769916a8e5..687c33abb8d 100644
--- a/addons/mrp_account/models/mrp_production.py
+++ b/addons/mrp_account/models/mrp_production.py
@@ -7,15 +7,6 @@ from odoo import api, fields, models, _
 from odoo.tools import float_is_zero, float_round
 
 
-class MrpProductionWorkcenterLineTime(models.Model):
-    _inherit = 'mrp.workcenter.productivity'
-
-    # checked when a ongoing production posts journal entries for its costs.
-    # This way, we can record one production's cost multiple times and only
-    # consider new entries in the work centers time lines."
-    cost_already_recorded = fields.Boolean('Cost Recorded')
-
-
 class MrpProduction(models.Model):
     _inherit = 'mrp.production'
 
@@ -87,12 +78,7 @@ class MrpProduction(models.Model):
         if finished_move:
             finished_move.ensure_one()
             for work_order in self.workorder_ids:
-                time_lines = work_order.time_ids.filtered(
-                    lambda x: x.date_end and not x.cost_already_recorded)
-                duration = sum(time_lines.mapped('duration'))
-                time_lines.write({'cost_already_recorded': True})
-                work_center_cost += (duration / 60.0) * \
-                    work_order.workcenter_id.costs_hour
+                work_center_cost += work_order._cal_cost()
             qty_done = finished_move.product_uom._compute_quantity(
                 finished_move.quantity_done, finished_move.product_id.uom_id)
             extra_cost = self.extra_cost * qty_done