Therefore, the consumption methods of the data and services should also change. The concept of "browsing the web" will be replaced by automated agents that access to structured content. Dialogue systems are a natural way to interact with the machine readable data and services on the web. Enabling such an interaction in a scalable way is only possible if the web services and the data are machine-readable. In this work, we will develop an approach for annotating web services with a lightweight semantic vocabulary based on schema.org and an approach for semi-automatically generating open and flexible goal-oriented dialogue systems based on those web services. These dialogue systems can complete tasks like booking a hotel room or buying a ticket for an event. We will apply our approach to e-tourism domain.