Management systems are designed to support nuclear organizations in achieving their objectives effectively, efficiently, and sustainably, while addressing all relevant requirements. These include safety, environmental, performance, reliability, and economic objectives, as well as meaningful engagement with interested parties. This publication provides technical guidance and showcases examples of international best practices for evaluating whether a management system is fit for purpose. It is intended for a broad audience, ranging from professionals involved in the daily implementation of management systems to individuals with a general interest in nuclear organizations. It covers all phases of the facility life cycle with a particular focus on the construction and operational stages.