diff --git a/doc/model.puml b/doc/model.puml
index e75a8c1..f73439e 100644
--- a/doc/model.puml
+++ b/doc/model.puml
@@ -57,15 +57,15 @@ class WorkflowSchedule {
 
 class Graph {
     +id: int
-    +ressources: Ressource[] 
+    +ressources: map[GraphicElement.ID]Ressource 
     +links: Link[] 
 }
 
 class Link {
     +id: int
-    +source: Ressource
-    +target: Ressource
-    graphic: GraphicLink
+    +source: GraphicElement.ID
+    +target: GraphicElement.ID
+    +graphic: GraphicLink
 }
 
 class GraphicLink {
@@ -124,13 +124,14 @@ Workflow "1" o-- "0..*" ResourceSet
 Workflow "1" o-- "0..*" WorkflowSchedule
 Workflow "1" o-- "0..*" Graph
 
-Graph "1" o-- "0..*" Ressource
+Graph "1" o-- "0..*" Resources
 Graph "1" o-- "0..*" Link
 
-Ressource -- GraphicElement
+Ressource --o GraphicElement
 Link -- GraphicLink
 
 
 Calendar "1" o-- "0..*" Workflow
 
+
 @enduml
\ No newline at end of file