Determining lean principle factors to achieve sustainable construction with time reduction emphasis

Sustainable construction, which has been dubbed as green construction, describes the responsibility of the construction industry in achieving a sustainable environment. The aim of this research is to determine the Lean Principles factors to achieve sustainable construction with time reduction emphasis. The methodology of mix methods consists of literature review, interviews, questionnaire survey and scheduling simulation. From the literature review, it shows clearly the sustainable construction is not focusing on time factor. This gap needs to be addressed because time is an important element in the construction life cycle. The questionnaire survey was distributed to the construction players and the results show the respondents give a high score on the implementation of sustainable construction because of the environmental issues rather than time. From the questionnaire also, the correlation analysis shows there was a strong correlation between the sustainable construction and lean principles in the view of time reduction. The construction scheduling simulation using Microsoft Project were used to see the time impact of conventional tall buildings when using Industrialized Building System (IBS) as a practical approach of Lean Principles. The scheduling simulation shows the time reduction in project completion. The conceptual framework has been established using Lean Principles in sustainable construction and the validation process of the framework showed that there is time reduction element if the framework is being implemented in the sustainable project. The average estimation of time reduction is 20% and majority of time reduction gained from construction stage in the project lifecycle. As conclusion, there were a significance relationship between Lean Principles in sustainable construction to achieve time reduction.