In this lecture the role of the physics of failure in maintenance will be discussed. Firstly the basics of the physics of failure will be introduced. After that, the benefits of understanding the failure mechanisms for maintenance are discussed, mainly focusing on three aspects: root cause analysis, predicting failures and improving the design. Also the challenges in this field will be discussed, for which many are related to collecting and analyzing data. Throughout the lecture, examples and practical cases from our research will be used to illustrate the various approaches.