مقاله سال ۲۰۱۶

    مهندسی عمران

Infrastructure projects provide necessary services and facilities for the economy of a country or region to function (Van Os et al., 2015). Such projects include but are not limited to building bridges, roads, tunnels, pipelines, electrical and telecommunication networks. Off-site construction processes have been increasingly used to deliver infrastructure projects (Construction, 2011).

A side-by-side progression of site-built and off-site activities in hybrid infrastructure projects provides many benefits such as schedule improvements (Dzeng and Lee, 2007), project cost savings (Arashpour et al., 2014a, 2014b), quality enhancements (Kim et al., 2014), site accident reductions (Blismas et al., 2006), and sustainability improvements (Xu et al., 2012).

However, activities in hybrid infrastructure project are often undertaken under uncertainty. Within the on-site dimension of such projects, there is uncertainty associated with weather conditions (Chan and Au, 2007), quality of assembly and installations (Gibb and Isack, 2003), and safety of heavy crane operations (Li et al., 2012). Within the off-site dimension of hybrid infrastructure projects, uncertainty is present in equipment failure rates (Ren et al., 2013), continuity of material supply (Arashpour et al., 2013), and precision of prefabrication (Yung and Yip, 2010). Furthermore, there is a third coordination dimension to hybrid projects that consists of transportation and communication activities with relevant associated uncertainty. Fig. 1 illustrates a simplified work breakdown structure for hybrid infrastructure projects as off-site/coordination/on-site triads.