diff --git a/force_bdss/core_plugins/csv_extractor/csv_extractor/csv_extractor_model.py b/force_bdss/core_plugins/csv_extractor/csv_extractor/csv_extractor_model.py
index 91682add3f7fb1ee9742f8a8b1bed64dd3595cbb..ad8d34bad87ce416d563346ef7d12257f3a01477 100644
--- a/force_bdss/core_plugins/csv_extractor/csv_extractor/csv_extractor_model.py
+++ b/force_bdss/core_plugins/csv_extractor/csv_extractor/csv_extractor_model.py
@@ -8,12 +8,3 @@ class CSVExtractorModel(BaseDataSourceModel):
     row = Int()
     column = Int()
     cuba_type = String()
-
-    @classmethod
-    def from_json(cls, json_data):
-        return cls(
-            filename=json_data["filename"],
-            row=json_data["row"],
-            column=json_data["column"],
-            cuba_type=json_data["cuba_type"]
-        )
diff --git a/force_bdss/core_plugins/dummy_mco/dakota/dakota_model.py b/force_bdss/core_plugins/dummy_mco/dakota/dakota_model.py
index 6b3ab63eb1c5491a7ef5c389c64bea074f3afd9c..b4c081a6b38bd5478f4287624411c5ce185cd01d 100644
--- a/force_bdss/core_plugins/dummy_mco/dakota/dakota_model.py
+++ b/force_bdss/core_plugins/dummy_mco/dakota/dakota_model.py
@@ -5,7 +5,3 @@ from force_bdss.api import BaseMCOModel
 
 class DakotaModel(BaseMCOModel):
     value_types = List(String)
-
-    @classmethod
-    def from_json(cls, model_data):
-        return cls(value_types=model_data["value_types"])
diff --git a/force_bdss/kpi/base_kpi_calculator_model.py b/force_bdss/kpi/base_kpi_calculator_model.py
index 9882fa605eeb44712f73c9ed9a8c5c7bdab414f0..f09122f2befb4e7926408495124e1bab2b5e5cb2 100644
--- a/force_bdss/kpi/base_kpi_calculator_model.py
+++ b/force_bdss/kpi/base_kpi_calculator_model.py
@@ -9,3 +9,4 @@ class BaseKPICalculatorModel(ABCHasStrictTraits):
     def __init__(self, bundle, *args, **kwargs):
         self.bundle = bundle
         super(BaseKPICalculatorModel, self).__init__(*args, **kwargs)
+