Based on the existing structural and system reliability analysis methods, structural availability was recently proposed for the yield strength of beam elements subjected to external random loads. Structural availability has the potential to deal with the features of operation and the maintenance of structures, as well as structural integrity, in a quantitative manner. This paper reports another investigation on structural availability following previous research. Among the two different themes of this study, one is the structural availability estimation on the buckling strength of beams using the same method that was previously proposed for yield strength, and the other is to formulate a general failure model that covers structural deterioration over time and then to compute the structural availability based on the failure model by means of a numerical method, such as Monte Carlo simulation. Relevant examples are also included in this article. This study is expected to help further understand the feasibility of structural availability application in the actual design process and the risk-based design of structures.