The design of adaptive e-learning systems has been approached from different points of view. Adaptive Educational Hypermedia (AEH) conceptual frameworks, usually decompose this problem into separate concerns: a User Model (UM), an Adaptation Model (AM), and a Domain Model (DM). Regarding Educational Modelling Languages (EMLs), they provide adaptation mechanisms such as the modelling of participants following conditional learning paths over a common content structure. The design of adaptive learning paths in EMLs (the Adaptation Model) is predefined during design-time, and no changes on it are allowed during run-time. In this paper we describe the support of dynamic adaptation features (run-time changes on models) using PoEML (Perspective-oriented EML) as modelling language, with focus on the execution model of the PoEML engine and on a SOA-based middleware used by authoring tools to invoke change primitives.