Purpose: This review paper aims to highlight the causes of delays (COD) and their interactions in construction projects, potentially aiding in timely completion and waste reduction through early anticipation. Design/methodology/approach: Forty-seven global literature were examined in detail to identify CODS and its interactions using the systematic literature review (SLR) method that utilised the PRISMA guidelines to ensure the studies reviewed were adequate to safeguard the robustness and comprehensiveness. Three-way analysis, such as Pareto, degree of centrality and loops, was undertaken to identify the critical Level 1,2 and 3 CODS that affect the Construction projects. Findings: The research findings demonstrate that 65 CODs in eight categories affect construction projects. The CODs act in coherence rather than silos; the CLD displays complex interconnections of 44 factors obtained through the pairwise comparison of the 47 identified literature of the SLR. Through its systematic analysis of interaction loops, this research identified Ten level 1 critical CODs, two second-level critical CODs and 4 Third-level critical CODs. “Contractors' excessive workload/beyond potential/inadequate experience” emerged as the top COD that affects scheduling and project delay. Research limitations/implications: The study limitations include using only English articles and a restricted number of databases. However, the chosen databases were reputable and underwent thorough peer review processes. This study may have limitations due to the SLR, which means that factors affecting COD and interactions may vary by country, and future research is suggested for validation. Practical implications: This study identified interactions of construction delays that potentially support scheduling risk management during the early stage of the project and reduce waste to improve sustainability. The theoretical implications of SLR-based research include helping develop a framework that would potentially have all COD in the current scenario and aid future academic and industrial research factor-wise and country-wise in aiding sustainability. This will support and provide construction professionals and academia with knowledge of the COD related to factors and their interactions to be considered in the early assessment and management of future projects and improve sustainability. Originality/value: Most literature studies the factors or causes of construction delays that affect construction projects. The CODs primarily do not operate in silos but combine with other causes to enhance their influence on delays. Hence, it is of utmost importance to study the interactions of COD to enhance the knowledge in the construction field that would aid in schedule repair and, in turn, on-time project delivery. The study is the first related to COD and their interactions in construction projects in the digital era.

New Zealand (NZ) construction is highly fragmented, comprises primarily micro small and medium enterprises (MSMEs); 32.5% of approximately 67,000 operating businesses are ‘small’ (up to 19 employees), while 65% are sole traders. The construction supply chain (CSC) is extensive, prone to inefficiencies at segmental boundaries accentuated by project-centric delivery. Conversely, it presents significant opportunity for consolidation and improved efficiency. Vertical integration and CSC management from the supplier-end rather than the project-end enable component elements to be individually independent in terms of ownership, while integrating their management above the tactical CSC level. This leads to improved operational philosophy and employment. Quantifying impacts, however, is a challenge due to lack of tangibility. This can be effectively overcome using quantifiable parameters associated with the CSC’s transport component. The paper investigates transport operations in a narrow NZ CSC segment over a three-month period to quantify improved performance using operational data and further potential for resource optimisation using operations research-based planning. Research outcomes point towards: (i) Fleet management strategy; (ii) Integrated planning and operational delivery; (iii) Non-price attributes in tendering/contracting; (iv) Change in the delivery model of manufactured construction products; (v) Information and communication technology-based solutions; and (vi) Integration of reverse logistics.

Purpose: This paper aims to highlight the factors affecting health and safety (H&S) and the SMART Technologies (ST) used to mitigate them in the construction industry through a range of selected papers to encourage readers and potential audiences to consider the need for intelligent technologies to minimize the risks of injuries, illnesses and severe harm in the construction industry.Design/methodology/approach: This paper adopts a double systematic literature review (SLR) to analyse studies investigating the factors affecting H&S and the ST in the construction industry using databases such as Google Scholar, Scopus, Science Direct and Emerald Insight publication.Findings: The SLR identified “fatal or focus five factors” that include objects Fall from heights (FFH) and trapped between objects; Falls, Trips and slips (FTS); Machinery/Equipment Malfunction and Moving Equipment; Pollutants: Chemicals, Airborne Dust, Asbestos; and Electrocution. The ST includes Safety Boots/SMART Glasses/SMART Helmet/SMART Vests/SMART PPE/SMART Watch, Mobile Apps, Building Information Modelling (BIM), Virtual Reality/Augmented Reality (VR/AR), Drones/Unmanned Aerial Vehicles and Wearable Technology/Mobile Sensors help mitigate the risk posed by “Fatal five”. However, other factors within the scope of ST, such as Weather Conditions, Vibrations, Violence, Disease and illness, Fire and Explosion and Over Exertion, are yet to be adopted in the field.Research limitations/implications: SLR methodology limitations of not obtaining the most updated field knowledge are critical and are offset by choosing 72% of H&S and 92% of SM review literature post-2017. Limitations to capturing articles because of the restriction of database access: only English language search and journals that are not a part of the databases selected are acknowledged. However, key database search that recognizes rigorous peer-reviewed articles offset these limitations. The researcher’s Bias is acknowledged.Practical implications: This paper unravels the construction H&S factors and their interlinks with ST, which would aid industry understanding and focus on mitigating associated risks. The paper highlights the Fatal five and trivial 15, which would help better understand the causes of the H&S risks. Further, the paper discusses ST’s connectivity, which would aid the organization’s overall H&S management. The practical and theoretical implications include a better understanding of all factors that affect H&S and ST available to help mitigate concerns. The operating managers could use the ST to reduce H&S risks at every construction process stage. This paper on H&S and ST and relationships can theorize that the construction industry is more likely to identify clear root causes of H&S and ST usage than previously. The theoretical implications include enhanced understanding for academics on H&S factors, ST and gaps in ST concerning H&S, which can be expanded to provide new insights into existing knowledge.Originality/value: This paper highlights all factors affecting H&S and ST that help mitigate associated risks and identifies the “Fatal five” factors. The paper is the first to highlight the factors affecting H&S combined with ST in use and their interactions. The paper also identified factors within the ST scope that are yet to be explored.

Arid and hot regions, like Saudi Arabia, utilize up to 60% of the country’s energy to regulate buildings’ indoor comfort. Energy efficiency is a long-term sustainability measure that is part of the government’s Vision 2030 strategy. A standard method of improving the thermal performance of buildings is through the use of insulation materials. Considering the cooling loads’ requirement and the Global Warming Potential (GWP), the present research evaluated the effectiveness of insulation materials, including extruded polystyrene, expanded polystyrene, rock wool, and glass wool in the hot, arid climate. For this case study, four similar villas facing the cardinal directions were selected from the residential project at Qassim University. HOBO data loggers were used to collect indoor temperature data. Thermal performance and Life Cycle Assessment (LCA) were conducted in accordance with Saudi Building Code-602 (SBC-602). Simulation outputs based on the four cardinal directions were used for assessing the thermal performance and LCA of the different thicknesses and densities of insulation materials. This was done using IESVE and SimaPro, IMPACR2002+, to assess their cooling load and GWP, respectively. The results suggest the potential for using lower insulation thickness for the northern and western façades without violating the SBC. The results obtained the actual thicknesses of the three insulation materials for achieving indoor temperatures in the four cardinal directions and the selection of materials and their densities along with associated GWP. The outputs of the study have been generalized in the form of a performance-based flowchart as a tool for selecting the type and thickness of thermal and environmental insulation in residential buildings in the Qassim region of Saudi Arabia.