Industrial facilities consist of the primary load-carrying structure and various process engineering components (secondary structures), which under seismic loading, may exhibit significant damage that may threaten their structural integrity with severe consequences on the population, the environment and the economy. Structures in industrial facilities vary widely from flexible piping to rigid machines and from small precision equipment to large cranes. Most machine installations have specific functions, including manufacturing precision, production efficiency, and supply capacity, thus the functional failure is as important as structural failure.

The seismic behaviour of industrial facilities was intensively studied with numerical models and several component-based fragility curves were developed. However, this approach does not consider the dynamic interaction between the structure and the secondary components and thus the effect of seismic response of the secondary components on the response of the structure and vice versa. Nevertheless, it is important to consider this interaction to correctly identify or to predict the damages.