An optimized hybrid decision support system for waste management in construction projects based on gray data: A case study in high-rise buildings

Currently, one of the most significant and fundamental challenges for governments is waste generated from the construction industry, a concern that underlines the importance of its proper management. This research identifies and analyzes the factors influencing waste production in constructing high-rise buildings in Design-Bid-Building contracts and their impacts on various materials. It also introduces a decision-making model based on gray data analysis to evaluate these factors and their implications. The findings categorized the factors into four groups: the design section contributes 12%, procurement contributes 40%, execution accounts for 36%, and miscellaneous factors, separate from the three main sections of the Design-Bid-Building contracts, constitute the remaining 12%. Furthermore, upon determining the extent of the influence of these factors on various materials, it was ascertained that rebar was most significantly affected.