Process models have been described by researchers starting in the mid 1990. Current state of the art in technology enhanced learning (TEL) systems development in combination with observations based on using of standards, existing process models, and on supervising team work in a series of diverse TEL systems, have led to the insight, that an extended approach is required. With a strong background in systems engineering, this led to the development of ROME (The Rostock model for systematically developing e-Learning products and services). From the perspective of ROME, the process model is an ideal type description of an interdisciplinary development process.