Identification of non-value adding (NVA) activities in precast concreteinstallation sites to achieve low-carbon installation

The lean production philosophy has been applied in the construction industry to reduce waste andincrease efficiency. It is until recently that the lean philosophy has proven to be effective to meet thechallenges of sustainable development. Many studies have shown that lean philosophy can be applied inprecast concrete factories to lower inventory, reduce waste and increase efficiency. However, the precastconcrete installation cycle should not be overlooked following a life cycle perspective. This study adoptsa weighted factor model comprising 30 contractors in the Singapore construction industry and a casestudy. Construction site layout management practices are investigated using the weighted factor model.Strategies to improve the construction site layout are presented in a case study. The results indicatedthat there are many non-value adding activities in the site layout management practices that contributeto an increase in the carbon emissions level. Little consideration of green building materials, improperspecifications of the precast concrete products, lack of an uninterrupted workflow, and inaccurate esti-mation of seem to be the most important ones. The results provide good practice guidance and can beused as a checklist for contractors to identify the NVA activities in the installation sites to achieve low-carbon installation. The results will also be useful for regulatory agencies to provide recommendationsfor contractors to improve the installation procedure and reduce carbon emissions