diff --git a/MaterialLib/MPL/Properties/AverageMolarMass.cpp b/MaterialLib/MPL/Properties/AverageMolarMass.cpp
index 54923693c1f719c4efdeaeba4162cac2d13db1ae..d5f51a7362e3ed896750b8c73668ccf8dae449bd 100644
--- a/MaterialLib/MPL/Properties/AverageMolarMass.cpp
+++ b/MaterialLib/MPL/Properties/AverageMolarMass.cpp
@@ -83,12 +83,12 @@ PropertyDataType AverageMolarMass::value(
 }
 
 PropertyDataType AverageMolarMass::dValue(
-    VariableArray const& variable_array, Variable const primary_variable,
+    VariableArray const& variable_array, Variable const variable,
     ParameterLib::SpatialPosition const& pos, double const t,
     double const dt) const
 {
-    if ((primary_variable != Variable::phase_pressure) &&
-        (primary_variable != Variable::temperature))
+    if ((variable != Variable::phase_pressure) &&
+        (variable != Variable::temperature))
     {
         OGS_FATAL(
             "AverageMolarMass::dValue is implemented for derivatives with "
@@ -114,7 +114,7 @@ PropertyDataType AverageMolarMass::dValue(
     // for binary phases only.
     auto const dxnC = phase->property(PropertyType::mole_fraction)
                           .template dValue<Eigen::Vector2d>(
-                              variable_array, primary_variable, pos, t, dt)[0];
+                              variable_array, variable, pos, t, dt)[0];
 
     auto const M_0 = phase->component(0)
                          .property(PropertyType::molar_mass)
@@ -128,10 +128,9 @@ PropertyDataType AverageMolarMass::dValue(
 }  // namespace MaterialPropertyLib
 
 PropertyDataType AverageMolarMass::d2Value(
-    VariableArray const& /*variable_array*/,
-    Variable const /*primary_variable1*/, Variable const /*primary_variable2*/,
-    ParameterLib::SpatialPosition const& /*pos*/, double const /*t*/,
-    double const /*dt*/) const
+    VariableArray const& /*variable_array*/, Variable const /*variable1*/,
+    Variable const /*variable2*/, ParameterLib::SpatialPosition const& /*pos*/,
+    double const /*t*/, double const /*dt*/) const
 {
     OGS_FATAL("AverageMolarMass::d2Value is not yet implemented.");
 
diff --git a/MaterialLib/MPL/Properties/AverageMolarMass.h b/MaterialLib/MPL/Properties/AverageMolarMass.h
index 72b2864c83f5578f1577e386581c39f47b6553f5..331d011174eed2ca254ff6aa78d2291eb4f330de 100644
--- a/MaterialLib/MPL/Properties/AverageMolarMass.h
+++ b/MaterialLib/MPL/Properties/AverageMolarMass.h
@@ -38,7 +38,7 @@ public:
                            double const /*t*/,
                            double const /*dt*/) const override;
     PropertyDataType dValue(VariableArray const& variable_array,
-                            Variable const primary_variable,
+                            Variable const variable,
                             ParameterLib::SpatialPosition const& /*pos*/,
                             double const /*t*/,
                             double const /*dt*/) const override;
diff --git a/MaterialLib/MPL/Properties/CapillaryPressureSaturation/CapillaryPressureRegularizedVanGenuchten.cpp b/MaterialLib/MPL/Properties/CapillaryPressureSaturation/CapillaryPressureRegularizedVanGenuchten.cpp
index 02069f2a1b105d159b0c80edb4aca45c9fbbaa96..88b1b66cddc2023e65be39928321bc3c079353da 100644
--- a/MaterialLib/MPL/Properties/CapillaryPressureSaturation/CapillaryPressureRegularizedVanGenuchten.cpp
+++ b/MaterialLib/MPL/Properties/CapillaryPressureSaturation/CapillaryPressureRegularizedVanGenuchten.cpp
@@ -68,11 +68,11 @@ PropertyDataType CapillaryPressureRegularizedVanGenuchten::value(
 }
 
 PropertyDataType CapillaryPressureRegularizedVanGenuchten::dValue(
-    VariableArray const& variable_array, Variable const primary_variable,
+    VariableArray const& variable_array, Variable const variable,
     ParameterLib::SpatialPosition const& /*pos*/, double const /*t*/,
     double const /*dt*/) const
 {
-    if (primary_variable != Variable::liquid_saturation)
+    if (variable != Variable::liquid_saturation)
     {
         OGS_FATAL(
             "CapillaryPressureRegularizedVanGenuchten::dValue is implemented "
diff --git a/MaterialLib/MPL/Properties/CapillaryPressureSaturation/CapillaryPressureVanGenuchten.cpp b/MaterialLib/MPL/Properties/CapillaryPressureSaturation/CapillaryPressureVanGenuchten.cpp
index c44eb6e4d0caf0b482e418dea6461e1a94455297..44487d006744c56978742e8cf50df36aaf9c7f7d 100644
--- a/MaterialLib/MPL/Properties/CapillaryPressureSaturation/CapillaryPressureVanGenuchten.cpp
+++ b/MaterialLib/MPL/Properties/CapillaryPressureSaturation/CapillaryPressureVanGenuchten.cpp
@@ -107,11 +107,11 @@ PropertyDataType CapillaryPressureVanGenuchten::value(
 }
 
 PropertyDataType CapillaryPressureVanGenuchten::dValue(
-    VariableArray const& variable_array, Variable const primary_variable,
+    VariableArray const& variable_array, Variable const variable,
     ParameterLib::SpatialPosition const& /*pos*/, double const /*t*/,
     double const /*dt*/) const
 {
-    if (primary_variable != Variable::liquid_saturation)
+    if (variable != Variable::liquid_saturation)
     {
         OGS_FATAL(
             "CapillaryPressureVanGenuchten::dValue is implemented for "
diff --git a/MaterialLib/MPL/Properties/CapillaryPressureSaturation/SaturationBrooksCorey.cpp b/MaterialLib/MPL/Properties/CapillaryPressureSaturation/SaturationBrooksCorey.cpp
index 36836d20b394b81a22d9151965a302b369cd9809..9780668df52526a871086299f73ce9d5c6af40a6 100644
--- a/MaterialLib/MPL/Properties/CapillaryPressureSaturation/SaturationBrooksCorey.cpp
+++ b/MaterialLib/MPL/Properties/CapillaryPressureSaturation/SaturationBrooksCorey.cpp
@@ -56,11 +56,11 @@ PropertyDataType SaturationBrooksCorey::value(
 }
 
 PropertyDataType SaturationBrooksCorey::dValue(
-    VariableArray const& variable_array, Variable const primary_variable,
+    VariableArray const& variable_array, Variable const variable,
     ParameterLib::SpatialPosition const& /*pos*/, double const /*t*/,
     double const /*dt*/) const
 {
-    if (primary_variable != Variable::capillary_pressure)
+    if (variable != Variable::capillary_pressure)
     {
         OGS_FATAL(
             "SaturationBrooksCorey::dValue is implemented for derivatives with "
@@ -85,13 +85,12 @@ PropertyDataType SaturationBrooksCorey::dValue(
 }
 
 PropertyDataType SaturationBrooksCorey::d2Value(
-    VariableArray const& variable_array, Variable const primary_variable1,
-    Variable const primary_variable2,
-    ParameterLib::SpatialPosition const& /*pos*/, double const /*t*/,
-    double const /*dt*/) const
+    VariableArray const& variable_array, Variable const variable1,
+    Variable const variable2, ParameterLib::SpatialPosition const& /*pos*/,
+    double const /*t*/, double const /*dt*/) const
 {
-    if ((primary_variable1 != Variable::capillary_pressure) &&
-        (primary_variable2 != Variable::capillary_pressure))
+    if ((variable1 != Variable::capillary_pressure) &&
+        (variable2 != Variable::capillary_pressure))
     {
         OGS_FATAL(
             "SaturationBrooksCorey::d2Value is implemented for derivatives "
diff --git a/MaterialLib/MPL/Properties/CapillaryPressureSaturation/SaturationExponential.cpp b/MaterialLib/MPL/Properties/CapillaryPressureSaturation/SaturationExponential.cpp
index af2a0869b29b441f388fcf39e4fd7c56d5d5c234..de7c3aa50b5879b195801b24afc0798dd1504fd9 100644
--- a/MaterialLib/MPL/Properties/CapillaryPressureSaturation/SaturationExponential.cpp
+++ b/MaterialLib/MPL/Properties/CapillaryPressureSaturation/SaturationExponential.cpp
@@ -58,11 +58,11 @@ PropertyDataType SaturationExponential::value(
 }
 
 PropertyDataType SaturationExponential::dValue(
-    VariableArray const& variable_array, Variable const primary_variable,
+    VariableArray const& variable_array, Variable const variable,
     ParameterLib::SpatialPosition const& /*pos*/, double const /*t*/,
     double const /*dt*/) const
 {
-    if (primary_variable != Variable::capillary_pressure)
+    if (variable != Variable::capillary_pressure)
     {
         OGS_FATAL(
             "SaturationExponential::dValue is implemented for derivatives with "
@@ -83,10 +83,9 @@ PropertyDataType SaturationExponential::dValue(
 }
 
 PropertyDataType SaturationExponential::d2Value(
-    VariableArray const& /*variable_array*/,
-    Variable const /*primary_variable1*/, Variable const /*primary_variable2*/,
-    ParameterLib::SpatialPosition const& /*pos*/, double const /*t*/,
-    double const /*dt*/) const
+    VariableArray const& /*variable_array*/, Variable const /*variable1*/,
+    Variable const /*variable2*/, ParameterLib::SpatialPosition const& /*pos*/,
+    double const /*t*/, double const /*dt*/) const
 {
     OGS_FATAL("SaturationExponential::d2Value() is not implemented.");
 }
diff --git a/MaterialLib/MPL/Properties/CapillaryPressureSaturation/SaturationExponential.h b/MaterialLib/MPL/Properties/CapillaryPressureSaturation/SaturationExponential.h
index f60d1624b91ff50066a8a90fca6fdb30a6f7a874..9cdde6acff5b20429334ef067f84b37db68ca9ed 100644
--- a/MaterialLib/MPL/Properties/CapillaryPressureSaturation/SaturationExponential.h
+++ b/MaterialLib/MPL/Properties/CapillaryPressureSaturation/SaturationExponential.h
@@ -68,13 +68,13 @@ public:
                            double const /*t*/,
                            double const /*dt*/) const override;
     PropertyDataType dValue(VariableArray const& variable_array,
-                            Variable const primary_variable,
+                            Variable const variable,
                             ParameterLib::SpatialPosition const& /*pos*/,
                             double const /*t*/,
                             double const /*dt*/) const override;
     PropertyDataType d2Value(VariableArray const& variable_array,
-                             Variable const /*primary_variable1*/,
-                             Variable const /*primary_variable2*/,
+                             Variable const /*variable1*/,
+                             Variable const /*variable2*/,
                              ParameterLib::SpatialPosition const& /*pos*/,
                              double const /*t*/,
                              double const /*dt*/) const override;
diff --git a/MaterialLib/MPL/Properties/CapillaryPressureSaturation/SaturationLiakopoulos.cpp b/MaterialLib/MPL/Properties/CapillaryPressureSaturation/SaturationLiakopoulos.cpp
index ae2017caa62abb306158c9a202b8a09148bba500..7536285d87df46962218206fa6eef3112f4ed0fc 100644
--- a/MaterialLib/MPL/Properties/CapillaryPressureSaturation/SaturationLiakopoulos.cpp
+++ b/MaterialLib/MPL/Properties/CapillaryPressureSaturation/SaturationLiakopoulos.cpp
@@ -37,11 +37,11 @@ PropertyDataType SaturationLiakopoulos::value(
 }
 
 PropertyDataType SaturationLiakopoulos::dValue(
-    VariableArray const& variable_array, Variable const primary_variable,
+    VariableArray const& variable_array, Variable const variable,
     ParameterLib::SpatialPosition const& /*pos*/, double const /*t*/,
     double const /*dt*/) const
 {
-    if (primary_variable != Variable::capillary_pressure)
+    if (variable != Variable::capillary_pressure)
     {
         OGS_FATAL(
             "SaturationLiakopoulos::dValue is implemented for derivatives with "
@@ -60,13 +60,12 @@ PropertyDataType SaturationLiakopoulos::dValue(
 }
 
 PropertyDataType SaturationLiakopoulos::d2Value(
-    VariableArray const& variable_array, Variable const primary_variable1,
-    Variable const primary_variable2,
-    ParameterLib::SpatialPosition const& /*pos*/, double const /*t*/,
-    double const /*dt*/) const
+    VariableArray const& variable_array, Variable const variable1,
+    Variable const variable2, ParameterLib::SpatialPosition const& /*pos*/,
+    double const /*t*/, double const /*dt*/) const
 {
-    if ((primary_variable1 != Variable::capillary_pressure) &&
-        (primary_variable2 != Variable::capillary_pressure))
+    if ((variable1 != Variable::capillary_pressure) &&
+        (variable2 != Variable::capillary_pressure))
     {
         OGS_FATAL(
             "SaturationLiakopoulos::d2Value is implemented for derivatives "
diff --git a/MaterialLib/MPL/Properties/CapillaryPressureSaturation/SaturationVanGenuchten.cpp b/MaterialLib/MPL/Properties/CapillaryPressureSaturation/SaturationVanGenuchten.cpp
index 472d3be853c047f2d2c00c889ace1b067a6c43df..2f53c7f119b7dac492b978d4761e75a16d0234b1 100644
--- a/MaterialLib/MPL/Properties/CapillaryPressureSaturation/SaturationVanGenuchten.cpp
+++ b/MaterialLib/MPL/Properties/CapillaryPressureSaturation/SaturationVanGenuchten.cpp
@@ -61,11 +61,11 @@ PropertyDataType SaturationVanGenuchten::value(
 }
 
 PropertyDataType SaturationVanGenuchten::dValue(
-    VariableArray const& variable_array, Variable const primary_variable,
+    VariableArray const& variable_array, Variable const variable,
     ParameterLib::SpatialPosition const& /*pos*/, double const /*t*/,
     double const /*dt*/) const
 {
-    if (primary_variable != Variable::capillary_pressure)
+    if (variable != Variable::capillary_pressure)
     {
         OGS_FATAL(
             "SaturationVanGenuchten::dValue is implemented for derivatives "
@@ -98,15 +98,14 @@ PropertyDataType SaturationVanGenuchten::dValue(
 }
 
 PropertyDataType SaturationVanGenuchten::d2Value(
-    VariableArray const& variable_array, Variable const primary_variable1,
-    Variable const primary_variable2,
-    ParameterLib::SpatialPosition const& /*pos*/, double const /*t*/,
-    double const /*dt*/) const
+    VariableArray const& variable_array, Variable const variable1,
+    Variable const variable2, ParameterLib::SpatialPosition const& /*pos*/,
+    double const /*t*/, double const /*dt*/) const
 {
-    (void)primary_variable1;
-    (void)primary_variable2;
-    assert((primary_variable1 == Variable::capillary_pressure) &&
-           (primary_variable2 == Variable::capillary_pressure) &&
+    (void)variable1;
+    (void)variable2;
+    assert((variable1 == Variable::capillary_pressure) &&
+           (variable2 == Variable::capillary_pressure) &&
            "SaturationVanGenuchten::d2Value is implemented for  derivatives "
            "with respect to capillary pressure only.");
 
diff --git a/MaterialLib/MPL/Properties/ClausiusClapeyron.cpp b/MaterialLib/MPL/Properties/ClausiusClapeyron.cpp
index c844d61ca68fc81f441e96063d42c1f2964a24a4..10172c0a62798d5b85f7c9d383775e7849413edf 100644
--- a/MaterialLib/MPL/Properties/ClausiusClapeyron.cpp
+++ b/MaterialLib/MPL/Properties/ClausiusClapeyron.cpp
@@ -88,7 +88,7 @@ PropertyDataType ClausiusClapeyron::value(
 }
 
 PropertyDataType ClausiusClapeyron::dValue(
-    VariableArray const& variable_array, Variable const primary_variable,
+    VariableArray const& variable_array, Variable const variable,
     ParameterLib::SpatialPosition const& pos, double const t,
     double const dt) const
 {
@@ -103,7 +103,7 @@ PropertyDataType ClausiusClapeyron::dValue(
     {
         return 0.;
     }
-    if (primary_variable == Variable::phase_pressure)
+    if (variable == Variable::phase_pressure)
     {
         return 0.;
     }
@@ -112,7 +112,7 @@ PropertyDataType ClausiusClapeyron::dValue(
     const double dh = variable_array.enthalpy_of_evaporation;
     const double p_vap = std::get<double>(value(variable_array, pos, t, dt));
 
-    if (primary_variable == Variable::temperature)
+    if (variable == Variable::temperature)
     {
         return p_vap * M * dh / (R * T * T);
     }
@@ -122,10 +122,9 @@ PropertyDataType ClausiusClapeyron::dValue(
 }
 
 PropertyDataType ClausiusClapeyron::d2Value(
-    VariableArray const& /*variable_array*/,
-    Variable const /*primary_variable1*/, Variable const /*primary_variable2*/,
-    ParameterLib::SpatialPosition const& /*pos*/, double const /*t*/,
-    double const /*dt*/) const
+    VariableArray const& /*variable_array*/, Variable const /*variable1*/,
+    Variable const /*variable2*/, ParameterLib::SpatialPosition const& /*pos*/,
+    double const /*t*/, double const /*dt*/) const
 {
     OGS_FATAL("ClausiusClapeyron::d2Value is not implemented.");
 }
diff --git a/MaterialLib/MPL/Properties/ClausiusClapeyron.h b/MaterialLib/MPL/Properties/ClausiusClapeyron.h
index 455fcc6e50c9f62bef21be4142a741a1f88a1486..4c02b9a94d1b015ea9bf904591352a53e4e6dd40 100644
--- a/MaterialLib/MPL/Properties/ClausiusClapeyron.h
+++ b/MaterialLib/MPL/Properties/ClausiusClapeyron.h
@@ -44,13 +44,13 @@ public:
                            double const t,
                            double const dt) const override;
     PropertyDataType dValue(VariableArray const& variable_array,
-                            Variable const primary_variable,
+                            Variable const variable,
                             ParameterLib::SpatialPosition const& pos,
                             double const t,
                             double const dt) const override;
     PropertyDataType d2Value(VariableArray const& variable_array,
-                             Variable const primary_variable1,
-                             Variable const primary_variable2,
+                             Variable const variable1,
+                             Variable const variable2,
                              ParameterLib::SpatialPosition const& pos,
                              double const t,
                              double const dt) const override;
diff --git a/MaterialLib/MPL/Properties/Curve.cpp b/MaterialLib/MPL/Properties/Curve.cpp
index eb7f75a0f80ab5753e3f77a525dbc5481b30990c..bc291a2ce0fe658310d38900cfe9a669b7995ad6 100644
--- a/MaterialLib/MPL/Properties/Curve.cpp
+++ b/MaterialLib/MPL/Properties/Curve.cpp
@@ -29,11 +29,11 @@ PropertyDataType Curve::value(VariableArray const& variable_array,
 }
 
 PropertyDataType Curve::dValue(VariableArray const& variable_array,
-                               Variable const primary_variable,
+                               Variable const variable,
                                ParameterLib::SpatialPosition const& /*pos*/,
                                double const /*t*/, double const /*dt*/) const
 {
-    if (primary_variable != independent_variable_)
+    if (variable != independent_variable_)
     {
         return 0.0;
     }
diff --git a/MaterialLib/MPL/Properties/Curve.h b/MaterialLib/MPL/Properties/Curve.h
index e29f452c65e289cb1fbdec2716f03c653a8b1e0f..f212e5e2e4d33d727bb88ea1227ceb0ed213a4f8 100644
--- a/MaterialLib/MPL/Properties/Curve.h
+++ b/MaterialLib/MPL/Properties/Curve.h
@@ -37,7 +37,7 @@ public:
     /// This method will compute the derivative of a property with respect to
     /// the given primary variable.
     PropertyDataType dValue(VariableArray const& variable_array,
-                            Variable const primary_variable,
+                            Variable const variable,
                             ParameterLib::SpatialPosition const& /*pos*/,
                             double const /*t*/,
                             double const /*dt*/) const override;
diff --git a/MaterialLib/MPL/Properties/Density/WaterVapourDensity.cpp b/MaterialLib/MPL/Properties/Density/WaterVapourDensity.cpp
index a294d8a6051353896de2ffe486b14fec0d3ce08d..f68b614283455cda9f8eae008ce0bba2b422a50d 100644
--- a/MaterialLib/MPL/Properties/Density/WaterVapourDensity.cpp
+++ b/MaterialLib/MPL/Properties/Density/WaterVapourDensity.cpp
@@ -52,7 +52,7 @@ PropertyDataType WaterVapourDensity::value(
 }
 
 PropertyDataType WaterVapourDensity::dValue(
-    VariableArray const& variable_array, Variable const primary_variable,
+    VariableArray const& variable_array, Variable const variable,
     ParameterLib::SpatialPosition const& /*pos*/, double const /*t*/,
     double const /*dt*/) const
 {
@@ -60,7 +60,7 @@ PropertyDataType WaterVapourDensity::dValue(
     double const T = variable_array.temperature;
     double const water_density = variable_array.density;
 
-    if (primary_variable == Variable::temperature)
+    if (variable == Variable::temperature)
     {
         double const h = humidity(T, p, water_density);
         double const rho_v = h * saturatedVaporDensity(T);
@@ -72,7 +72,7 @@ PropertyDataType WaterVapourDensity::dValue(
                                          SpecificGasConstant::WaterVapour);
     }
 
-    if (primary_variable == Variable::phase_pressure)
+    if (variable == Variable::phase_pressure)
     {
         double const factor =
             1.0 /
diff --git a/MaterialLib/MPL/Properties/Density/WaterVapourDensity.h b/MaterialLib/MPL/Properties/Density/WaterVapourDensity.h
index 098b0fc510a81db6cecf3b2dc060477039c2a36c..967342f481c7a0b5a1e20dcae8b5d62cb1695675 100644
--- a/MaterialLib/MPL/Properties/Density/WaterVapourDensity.h
+++ b/MaterialLib/MPL/Properties/Density/WaterVapourDensity.h
@@ -71,7 +71,7 @@ public:
     /// \return The derivative of  water vapour density with respect to
     /// temperature or phase (water) pressure.
     PropertyDataType dValue(VariableArray const& variable_array,
-                            Variable const primary_variable,
+                            Variable const variable,
                             ParameterLib::SpatialPosition const& pos,
                             double const t, double const dt) const override;
 };
diff --git a/MaterialLib/MPL/Properties/EmbeddedFracturePermeability.cpp b/MaterialLib/MPL/Properties/EmbeddedFracturePermeability.cpp
index 6998b4e8e7ac7cbe44dacb9f34af90e474adb3d7..45e2f537b20055e53134fb1c34a56eca948dbb03 100644
--- a/MaterialLib/MPL/Properties/EmbeddedFracturePermeability.cpp
+++ b/MaterialLib/MPL/Properties/EmbeddedFracturePermeability.cpp
@@ -92,11 +92,11 @@ PropertyDataType EmbeddedFracturePermeability<DisplacementDim>::value(
 
 template <int DisplacementDim>
 PropertyDataType EmbeddedFracturePermeability<DisplacementDim>::dValue(
-    VariableArray const& variable_array, Variable const primary_variable,
+    VariableArray const& variable_array, Variable const variable,
     ParameterLib::SpatialPosition const& pos, double const t,
     double const /*dt*/) const
 {
-    if (primary_variable != Variable::mechanical_strain)
+    if (variable != Variable::mechanical_strain)
     {
         OGS_FATAL(
             "EmbeddedFracturePermeability::dValue is implemented for "
diff --git a/MaterialLib/MPL/Properties/EmbeddedFracturePermeability.h b/MaterialLib/MPL/Properties/EmbeddedFracturePermeability.h
index 8f9a10ded24035b683cf560ac4d42185b330a0e5..6c41e86f2ecb636ab7366ba09a7d33c3769c928b 100644
--- a/MaterialLib/MPL/Properties/EmbeddedFracturePermeability.h
+++ b/MaterialLib/MPL/Properties/EmbeddedFracturePermeability.h
@@ -84,7 +84,7 @@ public:
                            ParameterLib::SpatialPosition const& pos,
                            double const t, double const dt) const override;
     PropertyDataType dValue(VariableArray const& variable_array,
-                            Variable const primary_variable,
+                            Variable const variable,
                             ParameterLib::SpatialPosition const& pos,
                             double const t, double const dt) const override;
 };
diff --git a/MaterialLib/MPL/Properties/Enthalpy/LinearWaterVapourLatentHeat.cpp b/MaterialLib/MPL/Properties/Enthalpy/LinearWaterVapourLatentHeat.cpp
index 5afd5d2ee55b7443dcd25ea4a16b9d3ce575ea26..146217ca77bb1a5d347e28526c279fc2cecdb677 100644
--- a/MaterialLib/MPL/Properties/Enthalpy/LinearWaterVapourLatentHeat.cpp
+++ b/MaterialLib/MPL/Properties/Enthalpy/LinearWaterVapourLatentHeat.cpp
@@ -31,11 +31,11 @@ PropertyDataType LinearWaterVapourLatentHeat::value(
 }
 
 PropertyDataType LinearWaterVapourLatentHeat::dValue(
-    VariableArray const& /*variable_array*/, Variable const primary_variable,
+    VariableArray const& /*variable_array*/, Variable const variable,
     ParameterLib::SpatialPosition const& /*pos*/, double const /*t*/,
     double const /*dt*/) const
 {
-    if (primary_variable == Variable::temperature)
+    if (variable == Variable::temperature)
     {
         return -2369.2;
     }
diff --git a/MaterialLib/MPL/Properties/Enthalpy/LinearWaterVapourLatentHeat.h b/MaterialLib/MPL/Properties/Enthalpy/LinearWaterVapourLatentHeat.h
index d685fe1c61145fd218e615c25252bc62556d17d9..975cd0591e61bbfc82f2ba021f3c0d88bacb64aa 100644
--- a/MaterialLib/MPL/Properties/Enthalpy/LinearWaterVapourLatentHeat.h
+++ b/MaterialLib/MPL/Properties/Enthalpy/LinearWaterVapourLatentHeat.h
@@ -57,7 +57,7 @@ public:
                            double const dt) const override;
 
     PropertyDataType dValue(VariableArray const& variable_array,
-                            Variable const primary_variable,
+                            Variable const variable,
                             ParameterLib::SpatialPosition const& pos,
                             double const t, double const dt) const override;
 };
diff --git a/MaterialLib/MPL/Properties/Enthalpy/WaterVapourLatentHeatWithCriticalTemperature.cpp b/MaterialLib/MPL/Properties/Enthalpy/WaterVapourLatentHeatWithCriticalTemperature.cpp
index 81a1b6546404dc5d5a457dcdb144faaea4b0fd9f..449796bf91b30649b41678ae6c26a6130dd5a5d5 100644
--- a/MaterialLib/MPL/Properties/Enthalpy/WaterVapourLatentHeatWithCriticalTemperature.cpp
+++ b/MaterialLib/MPL/Properties/Enthalpy/WaterVapourLatentHeatWithCriticalTemperature.cpp
@@ -71,11 +71,11 @@ PropertyDataType WaterVapourLatentHeatWithCriticalTemperature::value(
 }
 
 PropertyDataType WaterVapourLatentHeatWithCriticalTemperature::dValue(
-    VariableArray const& variable_array, Variable const primary_variable,
+    VariableArray const& variable_array, Variable const variable,
     ParameterLib::SpatialPosition const& /*pos*/, double const /*t*/,
     double const /*dt*/) const
 {
-    if (primary_variable != Variable::temperature)
+    if (variable != Variable::temperature)
     {
         OGS_FATAL(
             "WaterVapourLatentHeatWithCriticalTemperature::dValue is "
diff --git a/MaterialLib/MPL/Properties/Enthalpy/WaterVapourLatentHeatWithCriticalTemperature.h b/MaterialLib/MPL/Properties/Enthalpy/WaterVapourLatentHeatWithCriticalTemperature.h
index 5c0d02bb6e993567d23f0dda22a245f3e5646eb0..87a8f6c2ce3a44a588f40a86873d0d55ac01b4a0 100644
--- a/MaterialLib/MPL/Properties/Enthalpy/WaterVapourLatentHeatWithCriticalTemperature.h
+++ b/MaterialLib/MPL/Properties/Enthalpy/WaterVapourLatentHeatWithCriticalTemperature.h
@@ -82,7 +82,7 @@ public:
                            double const dt) const override;
 
     PropertyDataType dValue(VariableArray const& variable_array,
-                            Variable const primary_variable,
+                            Variable const variable,
                             ParameterLib::SpatialPosition const& pos,
                             double const t, double const dt) const override;
 };
diff --git a/MaterialLib/MPL/Properties/Exponential.cpp b/MaterialLib/MPL/Properties/Exponential.cpp
index 8e924c8ae5a00e979aab91ff8eb1f083a7c19a7c..40ddf9e4d899af985e78830a3e8d329044884e08 100644
--- a/MaterialLib/MPL/Properties/Exponential.cpp
+++ b/MaterialLib/MPL/Properties/Exponential.cpp
@@ -39,11 +39,11 @@ PropertyDataType Exponential::value(
 }
 
 PropertyDataType Exponential::dValue(
-    VariableArray const& variable_array, Variable const primary_variable,
+    VariableArray const& variable_array, Variable const variable,
     ParameterLib::SpatialPosition const& /*pos*/, double const /*t*/,
     double const /*dt*/) const
 {
-    if (exponent_data_.type != primary_variable)
+    if (exponent_data_.type != variable)
     {
         return 0.;
     }
diff --git a/MaterialLib/MPL/Properties/Exponential.h b/MaterialLib/MPL/Properties/Exponential.h
index 252bef62e55e745b8091934b0c78e494d0877bdf..65757129e294ae128dfb7acd4fba3fd596bfc588 100644
--- a/MaterialLib/MPL/Properties/Exponential.h
+++ b/MaterialLib/MPL/Properties/Exponential.h
@@ -55,7 +55,7 @@ public:
     /// This method will compute the derivative of a property with respect
     /// to the given primary variable.
     PropertyDataType dValue(VariableArray const& variable_array,
-                            Variable const primary_variable,
+                            Variable const variable,
                             ParameterLib::SpatialPosition const& /*pos*/,
                             double const /*t*/,
                             double const /*dt*/) const override;
diff --git a/MaterialLib/MPL/Properties/Function.cpp b/MaterialLib/MPL/Properties/Function.cpp
index f4faaa95dcbf5f59bd6626ba303cc205ffd073c3..97e0ae21a857fb26fc5dfa370c787d37f84ea235 100644
--- a/MaterialLib/MPL/Properties/Function.cpp
+++ b/MaterialLib/MPL/Properties/Function.cpp
@@ -191,21 +191,21 @@ PropertyDataType Function::value(VariableArray const& variable_array,
 }
 
 PropertyDataType Function::dValue(VariableArray const& variable_array,
-                                  Variable const primary_variable,
+                                  Variable const variable,
                                   ParameterLib::SpatialPosition const& /*pos*/,
                                   double const /*t*/, double const /*dt*/) const
 {
     auto const it = std::find_if(begin(dvalue_expressions_),
                                  end(dvalue_expressions_),
-                                 [&primary_variable](auto const& v)
-                                 { return v.first == primary_variable; });
+                                 [&variable](auto const& v)
+                                 { return v.first == variable; });
 
     if (it == end(dvalue_expressions_))
     {
         OGS_FATAL(
             "Requested derivative with respect to the variable {:s} not "
             "provided for Function-type property {:s}.",
-            variable_enum_to_string[static_cast<int>(primary_variable)], name_);
+            variable_enum_to_string[static_cast<int>(variable)], name_);
     }
 
     return evaluateExpressions(symbol_values_, variable_array, it->second);
diff --git a/MaterialLib/MPL/Properties/Function.h b/MaterialLib/MPL/Properties/Function.h
index 4c531baeb7d151af0c323016472e2e94dfed641d..bcd0f0d5c1b9f0abf78a7e3e3529f57cd0d7b0dc 100644
--- a/MaterialLib/MPL/Properties/Function.h
+++ b/MaterialLib/MPL/Properties/Function.h
@@ -38,7 +38,7 @@ public:
                            double const dt) const override;
 
     PropertyDataType dValue(VariableArray const& variable_array,
-                            Variable const primary_variable,
+                            Variable const variable,
                             ParameterLib::SpatialPosition const& pos,
                             double const t,
                             double const dt) const override;
diff --git a/MaterialLib/MPL/Properties/IdealGasLaw.cpp b/MaterialLib/MPL/Properties/IdealGasLaw.cpp
index bf824a08070a2c150152a77981d3d6340495b07a..d29340d27cdfef58dbfc1af3149b77181920f6d3 100644
--- a/MaterialLib/MPL/Properties/IdealGasLaw.cpp
+++ b/MaterialLib/MPL/Properties/IdealGasLaw.cpp
@@ -41,7 +41,7 @@ PropertyDataType IdealGasLaw::value(
 }
 
 PropertyDataType IdealGasLaw::dValue(
-    VariableArray const& variable_array, Variable const primary_variable,
+    VariableArray const& variable_array, Variable const variable,
     ParameterLib::SpatialPosition const& /*pos*/, double const /*t*/,
     double const /*dt*/) const
 {
@@ -51,14 +51,14 @@ PropertyDataType IdealGasLaw::dValue(
     const double molar_mass = variable_array.molar_mass;
     // todo: add molar mass derivatives
 
-    if (primary_variable == Variable::temperature)
+    if (variable == Variable::temperature)
     {
         // extend to take temperature-dependent molar mass into account
         return -pressure * molar_mass / gas_constant / temperature /
                temperature;
     }
 
-    if (primary_variable == Variable::phase_pressure)
+    if (variable == Variable::phase_pressure)
     {
         // extend to take pressure-dependent molar mass into account
         return molar_mass / gas_constant / temperature;
@@ -72,10 +72,9 @@ PropertyDataType IdealGasLaw::dValue(
 }
 
 PropertyDataType IdealGasLaw::d2Value(
-    VariableArray const& variable_array, Variable const primary_variable1,
-    Variable const primary_variable2,
-    ParameterLib::SpatialPosition const& /*pos*/, double const /*t*/,
-    double const /*dt*/) const
+    VariableArray const& variable_array, Variable const variable1,
+    Variable const variable2, ParameterLib::SpatialPosition const& /*pos*/,
+    double const /*t*/, double const /*dt*/) const
 {
     const double gas_constant = MaterialLib::PhysicalConstant::IdealGasConstant;
     const double pressure = variable_array.phase_pressure;
@@ -83,25 +82,25 @@ PropertyDataType IdealGasLaw::d2Value(
     const double molar_mass = variable_array.molar_mass;
     // todo: add molar mass derivatives
 
-    if ((primary_variable1 == Variable::phase_pressure) &&
-        (primary_variable2 == Variable::phase_pressure))
+    if ((variable1 == Variable::phase_pressure) &&
+        (variable2 == Variable::phase_pressure))
     {
         // d2rho_dp2
         // extend to take pressure-dependent molar mass into account
         return 0.;
     }
-    if ((primary_variable1 == Variable::temperature) &&
-        (primary_variable2 == Variable::temperature))
+    if ((variable1 == Variable::temperature) &&
+        (variable2 == Variable::temperature))
     {
         // d2rho_dT2
         // extend to take temperature-dependent molar mass into account
         return 2. * molar_mass * pressure / gas_constant / temperature /
                temperature / temperature;
     }
-    if (((primary_variable1 == Variable::phase_pressure) &&
-         (primary_variable2 == Variable::temperature)) ||
-        ((primary_variable1 == Variable::temperature) &&
-         (primary_variable2 == Variable::phase_pressure)))
+    if (((variable1 == Variable::phase_pressure) &&
+         (variable2 == Variable::temperature)) ||
+        ((variable1 == Variable::temperature) &&
+         (variable2 == Variable::phase_pressure)))
     {
         // d2rho_dpdT or d2rho_dTdp
         // extend to take pressure-temperature-dependent molar mass into account
diff --git a/MaterialLib/MPL/Properties/IdealGasLawBinaryMixture.cpp b/MaterialLib/MPL/Properties/IdealGasLawBinaryMixture.cpp
index 2894aa48312aa28b6da20b5f31ca96cb2ff942ee..81d2ef38d64aed515b6a2c80f3cf15fcc7e67651 100644
--- a/MaterialLib/MPL/Properties/IdealGasLawBinaryMixture.cpp
+++ b/MaterialLib/MPL/Properties/IdealGasLawBinaryMixture.cpp
@@ -67,10 +67,9 @@ PropertyDataType IdealGasLawBinaryMixture::dValue(
 }
 
 PropertyDataType IdealGasLawBinaryMixture::d2Value(
-    VariableArray const& /*variable_array*/,
-    Variable const /*primary_variable1*/, Variable const /*primary_variable2*/,
-    ParameterLib::SpatialPosition const& /*pos*/, double const /*t*/,
-    double const /*dt*/) const
+    VariableArray const& /*variable_array*/, Variable const /*variable1*/,
+    Variable const /*variable2*/, ParameterLib::SpatialPosition const& /*pos*/,
+    double const /*t*/, double const /*dt*/) const
 {
     OGS_FATAL("IdealGasLawBinaryMixture::d2Value is not implemented.");
 
diff --git a/MaterialLib/MPL/Properties/Linear.cpp b/MaterialLib/MPL/Properties/Linear.cpp
index df3d87d09d53eb33ac6febc870d8fe23a9bd9b18..6a39545a37cdc6e24b8c43c4b451f8c7dea823af 100644
--- a/MaterialLib/MPL/Properties/Linear.cpp
+++ b/MaterialLib/MPL/Properties/Linear.cpp
@@ -46,15 +46,14 @@ PropertyDataType Linear::value(VariableArray const& variable_array,
 }
 
 PropertyDataType Linear::dValue(VariableArray const& /*variable_array*/,
-                                Variable const primary_variable,
+                                Variable const variable,
                                 ParameterLib::SpatialPosition const& /*pos*/,
                                 double const /*t*/, double const /*dt*/) const
 {
-    auto const independent_variable =
-        std::find_if(independent_variables_.begin(),
-                     independent_variables_.end(),
-                     [&primary_variable](auto const& iv) -> bool
-                     { return iv.type == primary_variable; });
+    auto const independent_variable = std::find_if(
+        independent_variables_.begin(),
+        independent_variables_.end(),
+        [&variable](auto const& iv) -> bool { return iv.type == variable; });
 
     return independent_variable != independent_variables_.end()
                ? std::get<double>(value_) *
diff --git a/MaterialLib/MPL/Properties/Linear.h b/MaterialLib/MPL/Properties/Linear.h
index 484a9d1d45fa5fa2c54feafb7e8951721a1390bb..44765b88a6802941ed55e0166e6dfb490096637d 100644
--- a/MaterialLib/MPL/Properties/Linear.h
+++ b/MaterialLib/MPL/Properties/Linear.h
@@ -44,7 +44,7 @@ public:
     /// This method will compute the derivative of a property with respect to
     /// the given primary variable.
     PropertyDataType dValue(VariableArray const& variable_array,
-                            Variable const primary_variable,
+                            Variable const variable,
                             ParameterLib::SpatialPosition const& /*pos*/,
                             double const /*t*/,
                             double const /*dt*/) const override;
diff --git a/MaterialLib/MPL/Properties/OrthotropicEmbeddedFracturePermeability.cpp b/MaterialLib/MPL/Properties/OrthotropicEmbeddedFracturePermeability.cpp
index 29c46798ff5da8eb262ac5f783ca0c7bdd7d7b58..8031058036444677f8a40de60988ca3ae642b45e 100644
--- a/MaterialLib/MPL/Properties/OrthotropicEmbeddedFracturePermeability.cpp
+++ b/MaterialLib/MPL/Properties/OrthotropicEmbeddedFracturePermeability.cpp
@@ -87,11 +87,11 @@ OrthotropicEmbeddedFracturePermeability<DisplacementDim>::value(
 template <int DisplacementDim>
 PropertyDataType
 OrthotropicEmbeddedFracturePermeability<DisplacementDim>::dValue(
-    VariableArray const& variable_array, Variable const primary_variable,
+    VariableArray const& variable_array, Variable const variable,
     ParameterLib::SpatialPosition const& pos, double const t,
     double const /*dt*/) const
 {
-    if (primary_variable != Variable::mechanical_strain)
+    if (variable != Variable::mechanical_strain)
     {
         OGS_FATAL(
             "OrthotropicEmbeddedFracturePermeability::dValue is implemented "
diff --git a/MaterialLib/MPL/Properties/OrthotropicEmbeddedFracturePermeability.h b/MaterialLib/MPL/Properties/OrthotropicEmbeddedFracturePermeability.h
index 34ffadedf8c14d6a7b2fbb728531c3065f7dd40c..16fae69ddc8839812aa2ff1a0ba1cd3660b89044 100644
--- a/MaterialLib/MPL/Properties/OrthotropicEmbeddedFracturePermeability.h
+++ b/MaterialLib/MPL/Properties/OrthotropicEmbeddedFracturePermeability.h
@@ -87,7 +87,7 @@ public:
                            ParameterLib::SpatialPosition const& pos,
                            double const t, double const dt) const override;
     PropertyDataType dValue(VariableArray const& variable_array,
-                            Variable const primary_variable,
+                            Variable const variable,
                             ParameterLib::SpatialPosition const& pos,
                             double const t, double const dt) const override;
 };
diff --git a/MaterialLib/MPL/Properties/Parameter.cpp b/MaterialLib/MPL/Properties/Parameter.cpp
index c097d9d197aa7892a2fb666287683049a744c7ef..85e65e178ca5705fb893a69206b2b2810d9aac0c 100644
--- a/MaterialLib/MPL/Properties/Parameter.cpp
+++ b/MaterialLib/MPL/Properties/Parameter.cpp
@@ -35,7 +35,7 @@ PropertyDataType Parameter::value(VariableArray const& /*variable_array*/,
 }
 
 PropertyDataType Parameter::dValue(VariableArray const& /*variable_array*/,
-                                   Variable const /*primary_variable*/,
+                                   Variable const /*variable*/,
                                    ParameterLib::SpatialPosition const& /*pos*/,
                                    double const /*t*/,
                                    double const /*dt*/) const
diff --git a/MaterialLib/MPL/Properties/Parameter.h b/MaterialLib/MPL/Properties/Parameter.h
index 077282ff59062cd4393c3351d05ccbc5129ab610..f1adaf5be7b8dff782cf087b533125ac7c3aacca 100644
--- a/MaterialLib/MPL/Properties/Parameter.h
+++ b/MaterialLib/MPL/Properties/Parameter.h
@@ -39,7 +39,7 @@ public:
     /// This method will compute the derivative of a property with respect to
     /// the given primary variable.
     PropertyDataType dValue(VariableArray const& variable_array,
-                            Variable const primary_variable,
+                            Variable const variable,
                             ParameterLib::SpatialPosition const& /*pos*/,
                             double const /*t*/,
                             double const /*dt*/) const override;
diff --git a/MaterialLib/MPL/Properties/PermeabilityOrthotropicPowerLaw.cpp b/MaterialLib/MPL/Properties/PermeabilityOrthotropicPowerLaw.cpp
index 5bfc924f87ccf32bb3255d0ce59bf8e83126ee55..9093af7c66ab45909ba374d6af8d5593ca6553e2 100644
--- a/MaterialLib/MPL/Properties/PermeabilityOrthotropicPowerLaw.cpp
+++ b/MaterialLib/MPL/Properties/PermeabilityOrthotropicPowerLaw.cpp
@@ -86,11 +86,11 @@ PropertyDataType PermeabilityOrthotropicPowerLaw<DisplacementDim>::value(
 }
 template <int DisplacementDim>
 PropertyDataType PermeabilityOrthotropicPowerLaw<DisplacementDim>::dValue(
-    VariableArray const& /*variable_array*/, Variable const primary_variable,
+    VariableArray const& /*variable_array*/, Variable const variable,
     ParameterLib::SpatialPosition const& /*pos*/, double const /*t*/,
     double const /*dt*/) const
 {
-    if (primary_variable != Variable::total_strain)
+    if (variable != Variable::total_strain)
     {
         OGS_FATAL(
             "PermeabilityOrthotropicPowerLaw::dValue is implemented for "
diff --git a/MaterialLib/MPL/Properties/PorosityFromMassBalance.cpp b/MaterialLib/MPL/Properties/PorosityFromMassBalance.cpp
index 3c0196874d5906586ef7d96bb2a9670b03d35991..97a139d53ce4cc8ba31f90b83057bf08798bdc13 100644
--- a/MaterialLib/MPL/Properties/PorosityFromMassBalance.cpp
+++ b/MaterialLib/MPL/Properties/PorosityFromMassBalance.cpp
@@ -63,8 +63,7 @@ PropertyDataType PorosityFromMassBalance::value(
 }
 
 PropertyDataType PorosityFromMassBalance::dValue(
-    VariableArray const& /*variable_array*/,
-    Variable const /*primary_variable*/,
+    VariableArray const& /*variable_array*/, Variable const /*variable*/,
     ParameterLib::SpatialPosition const& /*pos*/, double const /*t*/,
     double const /*dt*/) const
 {
diff --git a/MaterialLib/MPL/Properties/RelativePermeability/RelPermUdellNonwettingPhase.cpp b/MaterialLib/MPL/Properties/RelativePermeability/RelPermUdellNonwettingPhase.cpp
index 4a5f231b4e60b364b53dd32e189fe9784c172bcd..760b8d5aa68dd9774cf53550b572fc0755612be2 100644
--- a/MaterialLib/MPL/Properties/RelativePermeability/RelPermUdellNonwettingPhase.cpp
+++ b/MaterialLib/MPL/Properties/RelativePermeability/RelPermUdellNonwettingPhase.cpp
@@ -67,11 +67,11 @@ PropertyDataType RelPermUdellNonwettingPhase::value(
     return std::max(min_relative_permeability_, S_e_g * S_e_g * S_e_g);
 }
 PropertyDataType RelPermUdellNonwettingPhase::dValue(
-    VariableArray const& variable_array, Variable const primary_variable,
+    VariableArray const& variable_array, Variable const variable,
     ParameterLib::SpatialPosition const& /*pos*/, double const /*t*/,
     double const /*dt*/) const
 {
-    if (primary_variable != Variable::liquid_saturation)
+    if (variable != Variable::liquid_saturation)
     {
         OGS_FATAL(
             "RelPermUdellNonwettingPhase::dValue is implemented for "
diff --git a/MaterialLib/MPL/Properties/RelativePermeability/RelPermUdellNonwettingPhase.h b/MaterialLib/MPL/Properties/RelativePermeability/RelPermUdellNonwettingPhase.h
index f7df53cef145af649a53bfcc02be667583bba642..f49ec4c2e6aa012b6d22df4a5851b239f568f38e 100644
--- a/MaterialLib/MPL/Properties/RelativePermeability/RelPermUdellNonwettingPhase.h
+++ b/MaterialLib/MPL/Properties/RelativePermeability/RelPermUdellNonwettingPhase.h
@@ -66,7 +66,7 @@ public:
                            ParameterLib::SpatialPosition const& pos,
                            double const t, double const dt) const override;
     PropertyDataType dValue(VariableArray const& variable_array,
-                            Variable const primary_variable,
+                            Variable const variable,
                             ParameterLib::SpatialPosition const& pos,
                             double const t, double const dt) const override;
 };
diff --git a/MaterialLib/MPL/Properties/RelativePermeability/RelPermVanGenuchten.cpp b/MaterialLib/MPL/Properties/RelativePermeability/RelPermVanGenuchten.cpp
index eaaf1e248ebe9cf9110ca2b7efb28ca714019887..beee8a916fe4eb822b020427876f6069b8f0abd8 100644
--- a/MaterialLib/MPL/Properties/RelativePermeability/RelPermVanGenuchten.cpp
+++ b/MaterialLib/MPL/Properties/RelativePermeability/RelPermVanGenuchten.cpp
@@ -54,11 +54,11 @@ PropertyDataType RelPermVanGenuchten::value(
 }
 
 PropertyDataType RelPermVanGenuchten::dValue(
-    VariableArray const& variable_array, Variable const primary_variable,
+    VariableArray const& variable_array, Variable const variable,
     ParameterLib::SpatialPosition const& /*pos*/, double const /*t*/,
     double const /*dt*/) const
 {
-    if (primary_variable != Variable::liquid_saturation)
+    if (variable != Variable::liquid_saturation)
     {
         OGS_FATAL(
             "RelativePermeabilityVanGenuchten::dValue is implemented for "
diff --git a/MaterialLib/MPL/Properties/SaturationDependentSwelling.cpp b/MaterialLib/MPL/Properties/SaturationDependentSwelling.cpp
index fbeb1d60a4229054890bbc8d5f8aff6c2875b8c5..68d8db3d8ff30319b986faa0140d10d8f5d887e8 100644
--- a/MaterialLib/MPL/Properties/SaturationDependentSwelling.cpp
+++ b/MaterialLib/MPL/Properties/SaturationDependentSwelling.cpp
@@ -103,11 +103,11 @@ PropertyDataType SaturationDependentSwelling::value(
 
 PropertyDataType SaturationDependentSwelling::dValue(
     VariableArray const& variable_array,
-    VariableArray const& variable_array_prev, Variable const primary_variable,
+    VariableArray const& variable_array_prev, Variable const variable,
     ParameterLib::SpatialPosition const& pos, double const /*t*/,
     double const /*dt*/) const
 {
-    if (primary_variable != Variable::liquid_saturation)
+    if (variable != Variable::liquid_saturation)
     {
         OGS_FATAL(
             "SaturationDependentSwelling::dValue is implemented for "
diff --git a/MaterialLib/MPL/Properties/TransportPorosityFromMassBalance.cpp b/MaterialLib/MPL/Properties/TransportPorosityFromMassBalance.cpp
index 93938219847613278590d21b289ac67e6f882e04..8a2573353865682060d6a86c95c083ca0448db46 100644
--- a/MaterialLib/MPL/Properties/TransportPorosityFromMassBalance.cpp
+++ b/MaterialLib/MPL/Properties/TransportPorosityFromMassBalance.cpp
@@ -65,8 +65,7 @@ PropertyDataType TransportPorosityFromMassBalance::value(
 }
 
 PropertyDataType TransportPorosityFromMassBalance::dValue(
-    VariableArray const& /*variable_array*/,
-    Variable const /*primary_variable*/,
+    VariableArray const& /*variable_array*/, Variable const /*variable*/,
     ParameterLib::SpatialPosition const& /*pos*/, double const /*t*/,
     double const /*dt*/) const
 {