diff --git a/.erdconfig b/.erdconfig
new file mode 100644
index 0000000000..9e85df5dd5
--- /dev/null
+++ b/.erdconfig
@@ -0,0 +1,3 @@
+indirect: false
+disconnected: false
+filename: doc/domain_model
diff --git a/doc/domain_model.pdf b/doc/domain_model.pdf
new file mode 100644
index 0000000000..fa0d12a8b0
Binary files /dev/null and b/doc/domain_model.pdf differ