diff --git a/src/main/java/org/gcube/informationsystem/parthenos/model/entity/D14_Software.java b/src/main/java/org/gcube/informationsystem/parthenos/model/entity/D14_Software.java
deleted file mode 100644
index 0508c75..0000000
--- a/src/main/java/org/gcube/informationsystem/parthenos/model/entity/D14_Software.java
+++ /dev/null
@@ -1,9 +0,0 @@
-package org.gcube.informationsystem.parthenos.model.entity;
-
-
-/**
-	 * @author Luca Frosini (ISTI - CNR)
-	 */
-public interface D14_Software {
-
-}
diff --git a/src/main/java/org/gcube/informationsystem/parthenos/model/entity/D1_Digital_Object.java b/src/main/java/org/gcube/informationsystem/parthenos/model/entity/D1_Digital_Object.java
deleted file mode 100644
index a453155..0000000
--- a/src/main/java/org/gcube/informationsystem/parthenos/model/entity/D1_Digital_Object.java
+++ /dev/null
@@ -1,9 +0,0 @@
-package org.gcube.informationsystem.parthenos.model.entity;
-
-
-/**
- * @author Luca Frosini (ISTI - CNR)
- */
-public interface D1_Digital_Object {
-
-}
diff --git a/src/main/java/org/gcube/informationsystem/parthenos/model/entity/E29_Design_or_Procedure.java b/src/main/java/org/gcube/informationsystem/parthenos/model/entity/E29_Design_or_Procedure.java
deleted file mode 100644
index 4990270..0000000
--- a/src/main/java/org/gcube/informationsystem/parthenos/model/entity/E29_Design_or_Procedure.java
+++ /dev/null
@@ -1,8 +0,0 @@
-package org.gcube.informationsystem.parthenos.model.entity;
-
-/**
- * @author Luca Frosini (ISTI - CNR)
- */
-public interface E29_Design_or_Procedure {
-
-}
diff --git a/src/main/java/org/gcube/informationsystem/parthenos/model/entity/E39_Actor.java b/src/main/java/org/gcube/informationsystem/parthenos/model/entity/E39_Actor.java
deleted file mode 100644
index b39c6f2..0000000
--- a/src/main/java/org/gcube/informationsystem/parthenos/model/entity/E39_Actor.java
+++ /dev/null
@@ -1,9 +0,0 @@
-package org.gcube.informationsystem.parthenos.model.entity;
-
-
-/**
- * @author Luca Frosini (ISTI - CNR)
- */
-public interface E39_Actor {
-
-}
diff --git a/src/main/java/org/gcube/informationsystem/parthenos/model/entity/E40_Legal_Body.java b/src/main/java/org/gcube/informationsystem/parthenos/model/entity/E40_Legal_Body.java
index 52ae314..f74fbb6 100644
--- a/src/main/java/org/gcube/informationsystem/parthenos/model/entity/E40_Legal_Body.java
+++ b/src/main/java/org/gcube/informationsystem/parthenos/model/entity/E40_Legal_Body.java
@@ -1,8 +1,10 @@
 package org.gcube.informationsystem.parthenos.model.entity;
 
+import org.gcube.informationsystem.model.entity.resource.LegalBody;
+
 /**
  * @author Luca Frosini (ISTI - CNR)
  */
-public interface E40_Legal_Body {
+public interface E40_Legal_Body extends LegalBody {
 
 }
diff --git a/src/main/java/org/gcube/informationsystem/parthenos/model/entity/E51_Contact_Point.java b/src/main/java/org/gcube/informationsystem/parthenos/model/entity/E51_Contact_Point.java
deleted file mode 100644
index d8086e4..0000000
--- a/src/main/java/org/gcube/informationsystem/parthenos/model/entity/E51_Contact_Point.java
+++ /dev/null
@@ -1,8 +0,0 @@
-package org.gcube.informationsystem.parthenos.model.entity;
-
-/**
- * @author Luca Frosini (ISTI - CNR)
- */
-public interface E51_Contact_Point {
-
-}
diff --git a/src/main/java/org/gcube/informationsystem/parthenos/model/entity/E7_Activity.java b/src/main/java/org/gcube/informationsystem/parthenos/model/entity/E7_Activity.java
index 65fda4b..08e0728 100644
--- a/src/main/java/org/gcube/informationsystem/parthenos/model/entity/E7_Activity.java
+++ b/src/main/java/org/gcube/informationsystem/parthenos/model/entity/E7_Activity.java
@@ -2,6 +2,7 @@ package org.gcube.informationsystem.parthenos.model.entity;
 
 /**
  * @author Luca Frosini (ISTI - CNR)
+ * TODO check if can be removed
  */
 public interface E7_Activity {
 
diff --git a/src/main/java/org/gcube/informationsystem/parthenos/model/entity/PE13_Software_Computing_E_Service.java b/src/main/java/org/gcube/informationsystem/parthenos/model/entity/PE13_Software_Computing_E_Service.java
index 3029617..7571997 100644
--- a/src/main/java/org/gcube/informationsystem/parthenos/model/entity/PE13_Software_Computing_E_Service.java
+++ b/src/main/java/org/gcube/informationsystem/parthenos/model/entity/PE13_Software_Computing_E_Service.java
@@ -4,6 +4,11 @@ import java.util.Collection;
 
 import javax.xml.datatype.XMLGregorianCalendar;
 
+import org.gcube.informationsystem.parthenos.model.entity.facet.PE29_Access_Point;
+import org.gcube.informationsystem.parthenos.model.entity.resource.D14_Software;
+import org.gcube.informationsystem.parthenos.model.entity.resource.D1_Digital_Object;
+import org.gcube.informationsystem.parthenos.model.entity.resource.E39_Actor;
+
 /**
 	 * @author Luca Frosini (ISTI - CNR)
 	 */
diff --git a/src/main/java/org/gcube/informationsystem/parthenos/model/entity/PE18_Dataset.java b/src/main/java/org/gcube/informationsystem/parthenos/model/entity/PE18_Dataset.java
deleted file mode 100644
index 38b35e7..0000000
--- a/src/main/java/org/gcube/informationsystem/parthenos/model/entity/PE18_Dataset.java
+++ /dev/null
@@ -1,8 +0,0 @@
-package org.gcube.informationsystem.parthenos.model.entity;
-
-/**
- * @author Luca Frosini (ISTI - CNR)
- */
-public interface PE18_Dataset extends D1_Digital_Object {
-
-}
diff --git a/src/main/java/org/gcube/informationsystem/parthenos/model/entity/PE19_Persistent_Digital_Object.java b/src/main/java/org/gcube/informationsystem/parthenos/model/entity/PE19_Persistent_Digital_Object.java
index 5a1063c..936a281 100644
--- a/src/main/java/org/gcube/informationsystem/parthenos/model/entity/PE19_Persistent_Digital_Object.java
+++ b/src/main/java/org/gcube/informationsystem/parthenos/model/entity/PE19_Persistent_Digital_Object.java
@@ -1,5 +1,7 @@
 package org.gcube.informationsystem.parthenos.model.entity;
 
+import org.gcube.informationsystem.parthenos.model.entity.resource.D1_Digital_Object;
+
 
 /**
  * @author Luca Frosini (ISTI - CNR)
diff --git a/src/main/java/org/gcube/informationsystem/parthenos/model/entity/PE1_Service.java b/src/main/java/org/gcube/informationsystem/parthenos/model/entity/PE1_Service.java
index 410be4b..0b47c58 100644
--- a/src/main/java/org/gcube/informationsystem/parthenos/model/entity/PE1_Service.java
+++ b/src/main/java/org/gcube/informationsystem/parthenos/model/entity/PE1_Service.java
@@ -1,9 +1,10 @@
 package org.gcube.informationsystem.parthenos.model.entity;
 
+import org.gcube.informationsystem.model.entity.resource.Service;
 
 /**
  * @author Luca Frosini (ISTI - CNR)
  */
-public interface PE1_Service extends E7_Activity {
+public interface PE1_Service extends Service, E7_Activity {
 
 }
diff --git a/src/main/java/org/gcube/informationsystem/parthenos/model/entity/PE20_Volatile_Digital_Object.java b/src/main/java/org/gcube/informationsystem/parthenos/model/entity/PE20_Volatile_Digital_Object.java
index 69938c7..9cbe75e 100644
--- a/src/main/java/org/gcube/informationsystem/parthenos/model/entity/PE20_Volatile_Digital_Object.java
+++ b/src/main/java/org/gcube/informationsystem/parthenos/model/entity/PE20_Volatile_Digital_Object.java
@@ -1,5 +1,7 @@
 package org.gcube.informationsystem.parthenos.model.entity;
 
+import org.gcube.informationsystem.parthenos.model.entity.resource.D1_Digital_Object;
+
 
 /**
  * @author Luca Frosini (ISTI - CNR)
diff --git a/src/main/java/org/gcube/informationsystem/parthenos/model/entity/PE21_Persistent_Software.java b/src/main/java/org/gcube/informationsystem/parthenos/model/entity/PE21_Persistent_Software.java
index a798e3b..f6a2161 100644
--- a/src/main/java/org/gcube/informationsystem/parthenos/model/entity/PE21_Persistent_Software.java
+++ b/src/main/java/org/gcube/informationsystem/parthenos/model/entity/PE21_Persistent_Software.java
@@ -1,5 +1,7 @@
 package org.gcube.informationsystem.parthenos.model.entity;
 
+import org.gcube.informationsystem.parthenos.model.entity.resource.D14_Software;
+
 
 /**
  * @author Luca Frosini (ISTI - CNR)
diff --git a/src/main/java/org/gcube/informationsystem/parthenos/model/entity/PE22_Persistent_Dataset.java b/src/main/java/org/gcube/informationsystem/parthenos/model/entity/PE22_Persistent_Dataset.java
index 4645d41..8dd8622 100644
--- a/src/main/java/org/gcube/informationsystem/parthenos/model/entity/PE22_Persistent_Dataset.java
+++ b/src/main/java/org/gcube/informationsystem/parthenos/model/entity/PE22_Persistent_Dataset.java
@@ -1,5 +1,7 @@
 package org.gcube.informationsystem.parthenos.model.entity;
 
+import org.gcube.informationsystem.parthenos.model.entity.resource.PE18_Dataset;
+
 
 /**
  * @author Luca Frosini (ISTI - CNR)
diff --git a/src/main/java/org/gcube/informationsystem/parthenos/model/entity/PE23_Volatile_Software.java b/src/main/java/org/gcube/informationsystem/parthenos/model/entity/PE23_Volatile_Software.java
index fb05840..44f62c5 100644
--- a/src/main/java/org/gcube/informationsystem/parthenos/model/entity/PE23_Volatile_Software.java
+++ b/src/main/java/org/gcube/informationsystem/parthenos/model/entity/PE23_Volatile_Software.java
@@ -1,5 +1,7 @@
 package org.gcube.informationsystem.parthenos.model.entity;
 
+import org.gcube.informationsystem.parthenos.model.entity.resource.D14_Software;
+
 /**
  * @author Luca Frosini (ISTI - CNR)
  */
diff --git a/src/main/java/org/gcube/informationsystem/parthenos/model/entity/PE24_Volatile_Dataset.java b/src/main/java/org/gcube/informationsystem/parthenos/model/entity/PE24_Volatile_Dataset.java
index 5df5e37..90ad4e6 100644
--- a/src/main/java/org/gcube/informationsystem/parthenos/model/entity/PE24_Volatile_Dataset.java
+++ b/src/main/java/org/gcube/informationsystem/parthenos/model/entity/PE24_Volatile_Dataset.java
@@ -1,5 +1,7 @@
 package org.gcube.informationsystem.parthenos.model.entity;
 
+import org.gcube.informationsystem.parthenos.model.entity.resource.PE18_Dataset;
+
 
 /**
  * @author Luca Frosini (ISTI - CNR)
diff --git a/src/main/java/org/gcube/informationsystem/parthenos/model/entity/PE28_Curation_Plan.java b/src/main/java/org/gcube/informationsystem/parthenos/model/entity/PE28_Curation_Plan.java
index b3917df..768537d 100644
--- a/src/main/java/org/gcube/informationsystem/parthenos/model/entity/PE28_Curation_Plan.java
+++ b/src/main/java/org/gcube/informationsystem/parthenos/model/entity/PE28_Curation_Plan.java
@@ -1,5 +1,7 @@
 package org.gcube.informationsystem.parthenos.model.entity;
 
+import org.gcube.informationsystem.parthenos.model.entity.resource.E29_Design_or_Procedure;
+
 
 /**
  * @author Luca Frosini (ISTI - CNR)
diff --git a/src/main/java/org/gcube/informationsystem/parthenos/model/entity/facet/E51_Contact_Point.java b/src/main/java/org/gcube/informationsystem/parthenos/model/entity/facet/E51_Contact_Point.java
new file mode 100644
index 0000000..760310a
--- /dev/null
+++ b/src/main/java/org/gcube/informationsystem/parthenos/model/entity/facet/E51_Contact_Point.java
@@ -0,0 +1,10 @@
+package org.gcube.informationsystem.parthenos.model.entity.facet;
+
+import org.gcube.informationsystem.model.entity.facet.ContactFacet;
+
+/**
+ * @author Luca Frosini (ISTI - CNR)
+ */
+public interface E51_Contact_Point extends ContactFacet {
+
+}
diff --git a/src/main/java/org/gcube/informationsystem/parthenos/model/entity/PE29_Access_Point.java b/src/main/java/org/gcube/informationsystem/parthenos/model/entity/facet/PE29_Access_Point.java
similarity index 62%
rename from src/main/java/org/gcube/informationsystem/parthenos/model/entity/PE29_Access_Point.java
rename to src/main/java/org/gcube/informationsystem/parthenos/model/entity/facet/PE29_Access_Point.java
index dad5ec9..4f4be45 100644
--- a/src/main/java/org/gcube/informationsystem/parthenos/model/entity/PE29_Access_Point.java
+++ b/src/main/java/org/gcube/informationsystem/parthenos/model/entity/facet/PE29_Access_Point.java
@@ -1,4 +1,5 @@
-package org.gcube.informationsystem.parthenos.model.entity;
+package org.gcube.informationsystem.parthenos.model.entity.facet;
+
 
 /**
  * @author Luca Frosini (ISTI - CNR)
diff --git a/src/main/java/org/gcube/informationsystem/parthenos/model/entity/resource/D14_Software.java b/src/main/java/org/gcube/informationsystem/parthenos/model/entity/resource/D14_Software.java
new file mode 100644
index 0000000..bbb8099
--- /dev/null
+++ b/src/main/java/org/gcube/informationsystem/parthenos/model/entity/resource/D14_Software.java
@@ -0,0 +1,11 @@
+package org.gcube.informationsystem.parthenos.model.entity.resource;
+
+import org.gcube.informationsystem.model.entity.resource.Software;
+
+/**
+ * @author Luca Frosini (ISTI - CNR)
+ * TODO check if can be removed
+ */
+public interface D14_Software extends Software {
+
+}
diff --git a/src/main/java/org/gcube/informationsystem/parthenos/model/entity/resource/D1_Digital_Object.java b/src/main/java/org/gcube/informationsystem/parthenos/model/entity/resource/D1_Digital_Object.java
new file mode 100644
index 0000000..ac891f0
--- /dev/null
+++ b/src/main/java/org/gcube/informationsystem/parthenos/model/entity/resource/D1_Digital_Object.java
@@ -0,0 +1,11 @@
+package org.gcube.informationsystem.parthenos.model.entity.resource;
+
+import org.gcube.informationsystem.model.entity.Resource;
+
+/**
+ * @author Luca Frosini (ISTI - CNR)
+ * TODO check if can be removed
+ */
+public interface D1_Digital_Object extends Resource {
+
+}
diff --git a/src/main/java/org/gcube/informationsystem/parthenos/model/entity/resource/E29_Design_or_Procedure.java b/src/main/java/org/gcube/informationsystem/parthenos/model/entity/resource/E29_Design_or_Procedure.java
new file mode 100644
index 0000000..544a9e1
--- /dev/null
+++ b/src/main/java/org/gcube/informationsystem/parthenos/model/entity/resource/E29_Design_or_Procedure.java
@@ -0,0 +1,10 @@
+package org.gcube.informationsystem.parthenos.model.entity.resource;
+
+import org.gcube.informationsystem.model.entity.Resource;
+
+/**
+ * @author Luca Frosini (ISTI - CNR)
+ */
+public interface E29_Design_or_Procedure extends Resource {
+
+}
diff --git a/src/main/java/org/gcube/informationsystem/parthenos/model/entity/resource/E39_Actor.java b/src/main/java/org/gcube/informationsystem/parthenos/model/entity/resource/E39_Actor.java
new file mode 100644
index 0000000..3595861
--- /dev/null
+++ b/src/main/java/org/gcube/informationsystem/parthenos/model/entity/resource/E39_Actor.java
@@ -0,0 +1,11 @@
+package org.gcube.informationsystem.parthenos.model.entity.resource;
+
+import org.gcube.informationsystem.model.entity.resource.Actor;
+
+
+/**
+ * @author Luca Frosini (ISTI - CNR)
+ */
+public interface E39_Actor extends Actor {
+
+}
diff --git a/src/main/java/org/gcube/informationsystem/parthenos/model/entity/resource/PE18_Dataset.java b/src/main/java/org/gcube/informationsystem/parthenos/model/entity/resource/PE18_Dataset.java
new file mode 100644
index 0000000..a119df1
--- /dev/null
+++ b/src/main/java/org/gcube/informationsystem/parthenos/model/entity/resource/PE18_Dataset.java
@@ -0,0 +1,10 @@
+package org.gcube.informationsystem.parthenos.model.entity.resource;
+
+import org.gcube.informationsystem.model.entity.resource.Dataset;
+
+/**
+ * @author Luca Frosini (ISTI - CNR)
+ */
+public interface PE18_Dataset extends Dataset, D1_Digital_Object {
+
+}
diff --git a/src/main/java/org/gcube/informationsystem/parthenos/model/relation/P1_is_identified_by.java b/src/main/java/org/gcube/informationsystem/parthenos/model/relation/P1_is_identified_by.java
deleted file mode 100644
index bee681c..0000000
--- a/src/main/java/org/gcube/informationsystem/parthenos/model/relation/P1_is_identified_by.java
+++ /dev/null
@@ -1,8 +0,0 @@
-package org.gcube.informationsystem.parthenos.model.relation;
-
-/**
- * @author Luca Frosini (ISTI - CNR)
- */
-public interface P1_is_identified_by {
-
-}
diff --git a/src/main/java/org/gcube/informationsystem/parthenos/model/relation/PP28_has_designated_access_point.java b/src/main/java/org/gcube/informationsystem/parthenos/model/relation/PP28_has_designated_access_point.java
index d472680..c033666 100644
--- a/src/main/java/org/gcube/informationsystem/parthenos/model/relation/PP28_has_designated_access_point.java
+++ b/src/main/java/org/gcube/informationsystem/parthenos/model/relation/PP28_has_designated_access_point.java
@@ -1,9 +1,13 @@
 package org.gcube.informationsystem.parthenos.model.relation;
 
+import org.gcube.informationsystem.parthenos.model.entity.PE8_E_Service;
+import org.gcube.informationsystem.parthenos.model.entity.facet.PE29_Access_Point;
+import org.gcube.informationsystem.parthenos.model.relation.consistsof.P1_is_identified_by;
 
 /**
  * @author Luca Frosini (ISTI - CNR)
  */
-public interface PP28_has_designated_access_point extends P1_is_identified_by {
+public interface PP28_has_designated_access_point<Out extends PE8_E_Service, In extends PE29_Access_Point>
+		extends P1_is_identified_by<Out, In> {
 
 }
diff --git a/src/main/java/org/gcube/informationsystem/parthenos/model/relation/consistsof/P1_is_identified_by.java b/src/main/java/org/gcube/informationsystem/parthenos/model/relation/consistsof/P1_is_identified_by.java
new file mode 100644
index 0000000..5588d0a
--- /dev/null
+++ b/src/main/java/org/gcube/informationsystem/parthenos/model/relation/consistsof/P1_is_identified_by.java
@@ -0,0 +1,13 @@
+package org.gcube.informationsystem.parthenos.model.relation.consistsof;
+
+import org.gcube.informationsystem.model.entity.Facet;
+import org.gcube.informationsystem.model.entity.Resource;
+import org.gcube.informationsystem.model.relation.IsIdentifiedBy;
+
+/**
+ * @author Luca Frosini (ISTI - CNR)
+ */
+public interface P1_is_identified_by<Out extends Resource, In extends Facet>
+		extends IsIdentifiedBy<Out, In> {
+
+}