--- /dev/null
+@startuml
+
+title Policy Execution
+
+participant REQUESTOR
+participant RESPONDEE
+participant PDP
+
+autonumber
+
+alt Synchronous Invocation
+ REQUESTOR --> PDP: Execute Policy
+ activate PDP
+ hnote over REQUESTOR : wait
+ PDP --> REQUESTOR: Policy Execution Result
+ deactivate PDP
+else Asynchronous Invocation
+ REQUESTOR --> PDP: Execute Policy
+ activate PDP
+ PDP --> RESPONDEE: Policy Execution Result
+ deactivate PDP
+end
+
+@enduml
\ No newline at end of file