Design and Certification for Facade Access Systems: An Alternative Risk-Based Method

Two new design and certification methodologies have been developed to compute the reliability of facade access systems using simplified risk-based procedures. These methods consider uncertainties in the loads, load effects, and component capacities to calculate individual component probabilities of failure. These probabilities are then used to compute an overall system probability of failure, which can be used for both design decision making and system certification purposes. A worked example is presented to fully demonstrate the certification procedure. In this paper, reliable procedures to certify and design facade access systems are both presented and demonstrated. These methods determine the risk of failure for each element of a facade access system and then use these to determine the risk of system failure. This risk of failure can then be compared against the desired maximum risk for failure of the system. These approaches are useful for efficiently computing the approximate reliability of a facade access system, which can then be used to inform design, certification, planning, and/or operation decision making. These are intended to be practical approaches to determine the reliability of a facade access system. As such, the necessary steps and equations for these methods are discussed, and a fully worked example is presented.