The main objectives of this book are to introduce maintenance strategies for electrical equipment and how to build a dynamic grouping maintenance strategy for a GDPS with consideration of dependencies between at both component and site level (economic, geographical dependencies) and impacts of dynamic contexts (i.e. varying deterioration rate of components, change of maintenance routes, maintenance opportunities, etc.). For this purpose, a cost structure and a dependence model considering both economic and geographical dependence are formulated. They are used as a basis for the development of the global model of maintenance routing and scheduling. In addition, an advanced algorithm using Genetic Algorithm and Branch and Bound is introduced to solve the joint optimization problem of maintenance routing and scheduling. Finally, the uses and advantages of the dynamic grouping maintenance strategy are illustrated through an application.