With the recognition that the engineering structures maintenance and repair needs far exceed the rescourses available to adress these needs, many firms have to turned to the development of ESMS (Enginnering Structures Management System) as a method to improve the allocation of these limited resources and the condition of their engineering structures. The paper provides an overviev of the need for ESMS. The concepts of level-of-service goals for functional adequacy, deterioration modeling and the relation of structural adequancy and optimization strategies for rescource allocation.