Self-organizing computing systems have become a major research area in the last years as they promise to handle the increasing complexity resulting from highly distributed systems and ubiquitous applications. Therefore, substantial effort has been spent in several research initiatives to address self-X features such as self-configuration, self-optimization, self-healing, self-protection etc. Moreover, real-time properties are required in many areas (such as embedded systems and distributed systems) self-organizing computing systems are dealing with. Combining the flexible and – to some extent – uncertain behavior of self-organizing systems with time-predictability necessary for real-time systems is a grand challenge. The sixth IEEE workshop on Self-Organizing Real-Time Systems (SORT 2015) will address these issues. It will be a forum for leading researchers to exchange ideas, presenting advances in state-of-the-art and brain-storming on promising directions for future research. This year’s edition of SORT will put a special focus on the design of self-building massively distributed computing systems.