diff --git a/force_bdss/io/workflow_reader.py b/force_bdss/io/workflow_reader.py
index c2d78ab745deb9309ed1926726d58b87a66644a9..5f286d800e1f4bc5a59cabbc9ef0ef5d434b50b3 100644
--- a/force_bdss/io/workflow_reader.py
+++ b/force_bdss/io/workflow_reader.py
@@ -91,7 +91,6 @@ class WorkflowReader(HasStrictTraits):
             wf_data = json_data["workflow"]
             wf.mco = self._extract_mco(wf_data)
             wf.execution_layers[:] = self._extract_execution_layers(wf_data)
-            wf.kpi_calculators[:] = self._extract_kpi_calculators(wf_data)
             wf.notification_listeners[:] = \
                 self._extract_notification_listeners(wf_data)
         except KeyError as e:
@@ -167,37 +166,6 @@ class WorkflowReader(HasStrictTraits):
 
         return layers
 
-    def _extract_kpi_calculators(self, wf_data):
-        """Extracts the KPI calculators from the workflow dictionary data.
-
-        Parameters
-        ----------
-        wf_data: dict
-            the content of the workflow key in the top level dictionary data.
-
-        Returns
-        -------
-        list of BaseKPICalculatorModel instances. Each BaseKPICalculatorModel
-        is an instance of the specific model class. The list can be
-        empty.
-        """
-        registry = self.factory_registry
-
-        kpi_calculators = []
-        for kpic_entry in wf_data["kpi_calculators"]:
-            kpic_id = kpic_entry["id"]
-            kpic_factory = registry.kpi_calculator_factory_by_id(kpic_id)
-            model_data = kpic_entry["model_data"]
-            model_data["input_slot_info"] = self._extract_input_slot_info(
-                model_data["input_slot_info"]
-            )
-
-            kpi_calculators.append(
-                kpic_factory.create_model(model_data)
-            )
-
-        return kpi_calculators
-
     def _extract_mco_parameters(self, mco_id, parameters_data):
         """Extracts the MCO parameters from the data as dictionary.
 
diff --git a/force_bdss/io/workflow_writer.py b/force_bdss/io/workflow_writer.py
index 22a7f185040f75afffe1b066c1c3111608a72459..f47981f7a77609adc6a472c9eb223e9265fad3aa 100644
--- a/force_bdss/io/workflow_writer.py
+++ b/force_bdss/io/workflow_writer.py
@@ -25,9 +25,6 @@ class WorkflowWriter(HasStrictTraits):
     def _workflow_data(self, workflow):
         workflow_data = {
             "mco": self._mco_data(workflow.mco),
-            "kpi_calculators": [
-                self._model_data(kpic)
-                for kpic in workflow.kpi_calculators],
             "execution_layers": [
                 self._execution_layer_data(el)
                 for el in workflow.execution_layers],