# Hybrid Methods for Selecting Precast Concrete Suppliers Based on Factory Capacity
## 1 Introduction  
The construction industry in the Kingdom of Saudi Arabia (KSA) is one of the fastest-growing sectors in the country. For the past 30 years, there has been a significant increase in construction projects across the KSA. This trend is driven by increased demand for housing, which is occasioned by several factors. First, the country has the largest population compared to other members of the Gulf Cooperation Council region [1]. Between 1974 and 2020, the population of the KSA increased from 7 million to 31 million [2]. As of 2022, the housing demand in the KSA is approximately four million housing units. Second, the KSA government has doubled its efforts to facilitate infrastructural developments. Such developments are geared towards realizing the country's economic and social reform plan,titled Saudi Vision 2030 [3]. The cities of Mecca and Medina attract the most religious tourists and Muslims annually [4]. This attraction explains the demand for accommodation, especially during the annual Islamic pilgrimage. Therefore, the construction industry is currently crucial to the KSA economy. Stakeholders in the KSA construction industry strive to adopt the best practices that facilitate the completion of quality projects in the shortest time possible. The KSA's Ministryof Housing approved the use of precast elements, among other modern construction methods, to address problems associated with traditional construction methods in the country [5]. Additionally, there is a substantial global shift towards minimizing the carbon footprints of new housing units. One way to achieve this is by using precast concrete instead of in situ concrete constructions. Many people also prefer precast concrete structures due to their superior resistance to fire, natural disasters, and attacks from mold and insects [6]. This reduction in emissions helps reduce the costs incurred for maintenance and insurance premiums. Precast concrete is also a suitable construction material because its density causes buildings to absorb sound effectively. The most appealing attribute of precast concrete is that it helps to reduce the duration of completing construction projects. Consequently, the project's subsequent phases commence immediately after the installation of precast structures. [PERSON] and [PERSON] [7] also add that using precast concrete enables project owners to minimize the cost of completing their projects. Successful construction project completion involves many stakeholders, including contractors, suppliers, and project owners. Many researchers have sought to identify the reasons behind incomplete projects and delays in completing construction projects in the KSA [8; 9; 10]. Any stakeholders listed above may hinder the successful execution of a construction project if they fail to promptly address issues arising from their roles. For instance, the acquisition of the required construction materials is fundamental to the successful completion of a project. Therefore, suppliers of construction materials should ensure they deliver quality materials promptly and at a relatively cheaper cost. [PERSON] et al. [9] identified delays in material delivery as the third major cause of project completion delays in the KSA. This interconnectedness is often formalized through contractual obligations, where suppliers are explicitly responsible for adhering to material specifications, delivery schedules, and quality standards. Failure to meet these contractual terms directly translates into project risks for the main contractor and, by extension, the project owner, necessitating robust supplier vetting. While the primary focus often lies on direct material suppliers, it is also important to recognize that main contractors frequently subcontract various project elements, creating a cascading risk effect. Subcontractors typically assume specific performance and delivery risks as defined in their agreements with the main contractor.