--- /dev/null
+# Auto-scaling VNF with horizontal scale out of VDUs #
+
+## Proposer ##
+**EUAG**
+
+## Type ##
+**Feature**
+
+## Target MDG/TF ##
+NBI, UI, LCM, RO, VCA
+
+## Description ##
+Some VNFs have the capability to scale by adding more VDU/VM without adding new
+internal VLDs and without changing the external connection points of the VNF, so
+that this scale out has no effect in other VNFs of a NS. This is the commonest
+case of scale out in cloud, so it is the most basic case to enable dynamicity in
+the use of resources. This feature aims to enable this capability in OSM.
+
+The end user might use the UI to request, for a given NS, an action to scale a
+VNF that is part of that NS. This action would be shown to the end user only if
+the VNF has the capability to scale.
+
+In other cases, the own VNF might have been authorized to trigger (or suggest) a
+scale out event based on pre-defined KPIs thresholds.
+
+Both use cases for driving scaling are considered of relevance for the project.
+
+## Demo or definition of done ##
+N/A