## 3 Findings
### Core Elements Underpinning SCM in the Construction Industry
#### 3.2.4 Best Practices  
Five elements are included in this subject area, i.e., 'continuous improvement', 'lean thinking', 'offset manufacturing', 'just-in-time' and'sustainability'. Continuous improvement refers to the continuous systematic planning and process development to achieve long-term performance improvement. It is not a one-off project initiative, and therefore, requires a joint effort of supply chain partners aiming to achieve the best value through long-term relationships [11]. Performance measurements are an important enabler of continuous improvement, making it possible to set some clear targets [87]. By comparing their performance against predefined goals, past performance or the 'best practice' performance, organizations can continuously learn and improve their processes [17], identifying the areas that need improvement and not adding value works that can be eliminated [10]. In this direction, lean thinking, a management approach influenced by the Toyota production system and widely recognized in many different industrial settings to improve supply chain performance, has been gradually adopted by the construction industry [15]. According to the Lean Enterprise Institute [119], its core objective is to maximize customer value while minimizing waste, considering waste as any effort that does not add value to the final product from the customer's point of view [75]. This includes material-related waste, to which the word waste predominantly refers in construction, but also waste associated with inputs such as workforce, time and equipment (e.g., activity start delays, network, unused employee creativity, long approval process, etc.) [90]. The core principles of lean thinking within the construction industry include waste reduction, process focus in production planning and control, end customer focus, continuous improvements, cooperative relationships and systems perspective [15]. To implement them, the industry adopted lean tools and techniques from manufacturing, such as Value Stream Mapping and Six Sigma, but also developed specifically conceived methods, such as the Last Planner System [91]. Lean thinking proves to be important to improve project performance in terms of time, cost and quality. Moreover, when integrated with SCM, with supply chain partners collaborating with each other, the opportunities to minimize waste and maximize value are much greater [66]. Both offsite manufacturing and just-in-time are considered central practices for waste reduction in lean thinking [15]. Notwithstanding, these two practices have also attracted the attention of practitioners and researchers apart from the lean literature and are, therefore, discussed in detail. There are various terms associated with offsite manufacturing (OSM), such as prefabrication, preassembly and modularization [4]. In this paper, OMS refers to production systems in which standardized building components, elements or units are prefabricated in factory-based production environments before being shipped for subsequent onsite installation [51; 66]. By moving traditionally onsite operations to areas under controlled conditions, OSM can lead to significant benefits such as construction time reduction, consistent quality, higher safety performance, improvements in constructability and a decrease in environmental impact [4]. However, shifting activities to remote locations also requires a higher level of integration among partners [57], such as manufacturing, transportation, inventory management and assembly sequences, which need to be carefully coordinated [51]. In this regard, just-in-time is a supply strategy that advocates smaller but more frequent deliveries to the construction site [15]. Its objective is to synchronize the delivery of materials with the assembly to minimize material buffers [41; 92]. By doing this, just-in-time contributes to eliminating waste caused by overproduction, waiting time,transportation, stocks and second handling of materials, generating positive effects for both suppliers and contractors [93].