One of the latest and most significant challenges in the domain of software development is the successful realization of good usability of the systems generated by this domain. Given the results of conducted surveys regarding the economical costs caused by a lack of software system's user friendliness this trend is the inevitable consequence and easily comprehensible. However, the prevalent models in the domain of software engineering do not sufficiently reflect the aspects of good usability. Thus it is often not possible to include the knowledge and expertise offered by usability experts and designers into the development process of software systems. To rise to that challenge this work proposes the structure and essential content for a reference model for interaction oriented systems, in an attempt to offer a fundamental, conceptual basis for an encompassing, interdisciplinary model in the domain of software development for human-computer-interaction.