In this article, we link the literatures on organizational routines and the management of uncertainties in order to establish the concept of flexible routines. Supported by flexible rules, this type of routine is argued to help achieve the right balance between standardization and flexibility, thus enabling resilience through loose coupling in high-risk organizations. The operationalization of the concept of flexible routine can help strategic decision-making regarding the design of high-risk systems as well as operational decision-making in the course of handling complex work processes. To underpin these arguments, findings from a case study on rules management in a railway organization are presented, where alignment of rules with the amount of uncertainty and actors’ competencies for handling uncertainties were analyzed. Implications for future research on flexible routines are discussed.