“…These constituents interact to form a collective system, herein referred to as coupled model . Such focus is relevant as many numerical models in civil and infrastructure engineering are indeed coupled models that are an amalgam of multiple constituents or systems of constituents; see, for instance, the published literature on soil–structure interaction (Provenzano, 2003; Qian and Zhang, 1993), fluid–structure interaction (Kutay and Aydilek, 2009; Caracoglia et al, 2009), human–structure interaction (Macdonald, 2009; Wang et al, 2011), and the broad field of substructuring (or subdomains), which essentially focuses on structure–structure interaction (Mahjoubi et al, 2009; Mahjoubi et al, 2011). While aiming to improve the predictive accuracy of such coupled simulation models, one obvious question arises: to achieve the greatest reduction in model uncertainty and bias, which constituent must be given the highest priority for further code development?…”