## 4 Discussion  
A total of 108 articles formed the final sample of this review. The majority was focused on specific topics regarding just one subject area (i.e., 55% contributed to only one core element and 7% to more than one core element). Nearly 27% of the articles contributed to two subject areas and the last 11% contributed to more than two subject areas. Neither of them concurrently discussed elements included in the five subject areas. This confirms the point made by [26] that most studies focus on specific areas and reinforces the research gap: there is a clear need to present a total solution for SCM in the construction industry. The review of research into core concepts and practices underpinning SCM in the construction industry, as identified through the systematic review procedures, coded into elements and classified into subject areas according to [PERSON] et al. 's [27] framework, produced a comprehensive picture of the current state of knowledge in this area (see Table 1). It integrates different perspectives and contributions made by the extant literature over the years to present a global perspective of SCM in the construction industry. Figure 7 shows the number of articles that contributed to each subject area. The first subject area, strategic management, brought together the elements that promote a strategic orientation toward SCM adoption. The results show that effective implementation of SCM requires defining a strategy that takes a systems approach to view the supply chain as a single entity. Intra-firm and inter-firm capabilities must be synchronized and converge into a unified force in pursuit of customer value [120]. Findings also suggest that this strategic perspective requires firms to have proper capabilities and motivation to embrace change. These insights echo the previous work of [PERSON] et al. [121], who discussed the concept of supply chain orientation as an antecedent to SCM. According to the authors, supply chain-oriented organizations place strategic emphasis on systemic, integrated SCM, and support this emphasis with an organizational structure (e.g., employees with key SCM skills, metrics to facilitate SC alignment and motivation, etc.) that capitalizes on this strategy. The following subject area, logistics, can be traced back into the origins of SCM and relates to the effective management of materials and information flows [120; 122]. The significant representativeness of materials transportation in total costs has spurred scholarly research into this topic. As presented by [123], numerous models to facilitate decisions that play important roles in the planning and control of material flows were identified in the literature. Moreover, findings suggest that the industry has started its own development and experimentation of new technologies intended to enhance real-time integration of material and information flows. These applications, as highlighted by [124], could help to solve many of the shortcomings of traditional logistics and improve construction quality. Coherently with the work of [125], the review also pointed to efficiency potentials in expanding the scope of logistics management beyond the individual construction site to include coordination across supply chains and construction sites. Although such approaches present challenges in terms of more advanced coordination amongst the actors involved, the advancement of new technologies is argued to open up for new ways of organizing the work more efficiently [55]. Figure 7: Number of articles that contributed to each subject area. Note: Some articles cover more than one subject area. Relationships, associated with the management of the interface relationships within and between various supply chain members, are another key aspect of SCM [122]. As defined by [126], the focus of supply chain management is upon the management of relationships to deliver better customer value at less cost to the supply chain as a whole.