ABSTRACT
This chapter focuses on how to deal with the variations in loads as encountered in nature and with the strengths of structures, which also show variations and which decreases after construction. Maintenance and repair are therefore important to maintain the strength of a structure in time. Several ways of maintenance are mentioned. For protections, a state-based maintenance approach is usually the most appropriate. Inspection is an essential part of a state-based maintenance approach. An overview of all relevant failure mechanisms is essential to be able to create a "fool proof" design. This overview can best be presented by combining the mechanisms in a fault tree. A brainstorm session with several experts can help to avoid overlooking a relevant mechanism. This is important, since most structures do not fail because of an underestimation of the load, but due to an important failure mechanism, which has been overlooked.
