A review of components and configurations of survey research in lean construction

The reliability of research is substantially linked with its methodology and design. The use of surveys is one of the methods that has been commonly used in research projects. Therefore, identifying the active state and classification of the mechanisms used by the survey studies can help increase the quality of future research. Accordingly, this study reviews survey literatures on Lean Construction to identify their common components along with their configurations. To achieve this goal, a total number of seventy studies were randomly sampled from the publications pool and reviewed. Afterwards, their bibliographic and content characteristics were extracted and analysed and a total of seven common components as well as three dominant configurations were found. Through a thematic analysis, twelve main themes were identified which were further sorted by their observed frequency. The result shows the relationship between the themes and the configurations applied by the studies so far. It also discloses an overall status of the survey research in Lean Construction which can be used as a valuable lead for researchers to choose the orientation and design of their future research projects

Labor Waste in Housing Construction Projects: An empirical study

Purpose - High-level labor waste is a major challenge in construction projects. This paper aims to identify, quantify and categorize labor waste in the context of Iranian housing construction projects. Design/methodology/approach – This research uses a case study approach, with empirical data collected through direct observations and semi-structured interviews. Findings – Having triangulated the findings from the literature review and empirical studies, a list of eight types of waste was derived for the thirteen observed laborers in ten case study projects. The empirical studies allowed the labor waste identified from the literature to be verified and refined by considering it in the context of the observed activities, and led to two new types of waste being identified which were not considered in the literature. Findings indicate that nearly 62% of laborers’ time is spent on non-value adding activities. It appeared that ‘unnecessary movement’, ‘waiting’ and ‘indirect work’ make up the highest labor waste. Research limitations/implications - This research focuses only on onsite resource flows in a housing construction site. It does not include offsite flows such as material delivery to site. Originality/value - The findings have provided substantial evidence on type and amount of labor waste and provide a solid basis to stimulate construction actors to participate in reducing labor waste and improving productivity

Investigation of the construction supply chain vulnerabilities under an unfavorable macro-environmental context

International trades rely on robust supply chains. However, supply chains are vulnerable to disruptions. Before implementing lean construction, identifying construction supply chain vulnerabilities (CSCV) is crucial to avoid failure. Meanwhile, an unfavorable macro-environmental context (e.g., challenging economic and political situations) can potentially affect the behavior of CSCV. This paper aims to identify and prioritize CSCV under an unfavorable macro-environmental context in a real-world case and then analyze the changes in CSCV in a period coinciding with the Covid-19 outbreak. A literature review led us to extract 26 variables that were then prioritized using the responses from questionnaires distributed among 72 participants in the studied country. A descriptive statistical approach was used to analyze the results, which showed that unlike the normal contexts mentioned in previous studies, under an unfavorable context, such CSCV as "price and exchange rate fluctuations", "supply-demand volatility", "financial issues", and "political challenges" gained priority. Moreover, analyzing the changes in CSCV indicated that the studied construction supply chain has become more vulnerable in the mentioned period. Considering the identified CSCV, this paper suggests that managers focus more on tools such as the Last Planner System and value stream mapping when implementing lean

Investigation of the construction supply chain vulnerabilities under an unfavorable macro-environmental context

International trades rely on robust supply chains. However, supply chains are vulnerable to disruptions. Before implementing lean construction, identifying construction supply chain vulnerabilities (CSCV) is crucial to avoid failure. Meanwhile, an unfavorable macro-environmental context (e.g., challenging economic and political situations) can potentially affect the behavior of CSCV. This paper aims to identify and prioritize CSCV under an unfavorable macro-environmental context in a real-world case and then analyze the changes in CSCV in a period coinciding with the Covid-19 outbreak. A literature review led us to extract 26 variables that were then prioritized using the responses from questionnaires distributed among 72 participants in the studied country. A descriptive statistical approach was used to analyze the results, which showed that unlike the normal contexts mentioned in previous studies, under an unfavorable context, such CSCV as "price and exchange rate fluctuations", "supply-demand volatility", "financial issues", and "political challenges" gained priority. Moreover, analyzing the changes in CSCV indicated that the studied construction supply chain has become more vulnerable in the mentioned period. Considering the identified CSCV, this paper suggests that managers focus more on tools such as the Last Planner System and value stream mapping when implementing lean

Age–sex differences in the global burden of lower respiratory infections and risk factors, 1990–2019: results from the Global Burden of Disease Study 2019

Summary Background The global burden of lower respiratory infections (LRIs) and corresponding risk factors in children older than 5 years and adults has not been studied as comprehensively as it has been in children younger than 5 years. We assessed the burden and trends of LRIs and risk factors across all age groups by sex, for 204 countries and territories. Methods In this analysis of data for the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019, we used clinician-diagnosed pneumonia or bronchiolitis as our case definition for LRIs. We included International Classification of Diseases 9th edition codes 079.6, 466–469, 470.0, 480–482.8, 483.0–483.9, 484.1–484.2, 484.6–484.7, and 487–489 and International Classification of Diseases 10th edition codes A48.1, A70, B97.4–B97.6, J09–J15.8, J16–J16.9, J20–J21.9, J91.0, P23.0–P23.4, and U04–U04.9. We used the Cause of Death Ensemble modelling strategy to analyse 23 109 site-years of vital registration data, 825 site-years of sample vital registration data, 1766 site-years of verbal autopsy data, and 681 site-years of mortality surveillance data. We used DisMod-MR 2.1, a Bayesian meta-regression tool, to analyse age–sex-specific incidence and prevalence data identified via systematic reviews of the literature, population-based survey data, and claims and inpatient data. Additionally, we estimated age–sex-specific LRI mortality that is attributable to the independent effects of 14 risk factors. Findings Globally, in 2019, we estimated that there were 257 million (95% uncertainty interval [UI] 240–275) LRI incident episodes in males and 232 million (217–248) in females. In the same year, LRIs accounted for 1·30 million (95% UI 1·18–1·42) male deaths and 1·20 million (1·07–1·33) female deaths. Age-standardised incidence and mortality rates were 1·17 times (95% UI 1·16–1·18) and 1·31 times (95% UI 1·23–1·41) greater in males than in females in 2019. Between 1990 and 2019, LRI incidence and mortality rates declined at different rates across age groups and an increase in LRI episodes and deaths was estimated among all adult age groups, with males aged 70 years and older having the highest increase in LRI episodes (126·0% [95% UI 121·4–131·1]) and deaths (100·0% [83·4–115·9]). During the same period, LRI episodes and deaths in children younger than 15 years were estimated to have decreased, and the greatest decline was observed for LRI deaths in males younger than 5 years (–70·7% [–77·2 to –61·8]). The leading risk factors for LRI mortality varied across age groups and sex. More than half of global LRI deaths in children younger than 5 years were attributable to child wasting (population attributable fraction [PAF] 53·0% [95% UI 37·7–61·8] in males and 56·4% [40·7–65·1] in females), and more than a quarter of LRI deaths among those aged 5–14 years were attributable to household air pollution (PAF 26·0% [95% UI 16·6–35·5] for males and PAF 25·8% [16·3–35·4] for females). PAFs of male LRI deaths attributed to smoking were 20·4% (95% UI 15·4–25·2) in those aged 15–49 years, 30·5% (24·1–36·9) in those aged 50–69 years, and 21·9% (16·8–27·3) in those aged 70 years and older. PAFs of female LRI deaths attributed to household air pollution were 21·1% (95% UI 14·5–27·9) in those aged 15–49 years and 18·2% (12·5–24·5) in those aged 50–69 years. For females aged 70 years and older, the leading risk factor, ambient particulate matter, was responsible for 11·7% (95% UI 8·2–15·8) of LRI deaths. Interpretation The patterns and progress in reducing the burden of LRIs and key risk factors for mortality varied across age groups and sexes. The progress seen in children younger than 5 years was clearly a result of targeted interventions, such as vaccination and reduction of exposure to risk factors. Similar interventions for other age groups could contribute to the achievement of multiple Sustainable Development Goals targets, including promoting wellbeing at all ages and reducing health inequalities. Interventions, including addressing risk factors such as child wasting, smoking, ambient particulate matter pollution, and household air pollution, would prevent deaths and reduce health disparities