This paper presents a study conducted to identify, assess, rank, and compare the most influencing factors causing schedule delays during the construction phase of petrochemical projects in Saudi Arabia. The methodology followed in this research to achieve the main aims is a combination of the comprehensive review of the literature and the interviewing of a number of local experts, which have resulted in identifying 23 factors. A total of 90 completed responses were gathered from 106 received responses. The study found that the most influencing factors causing schedule delays during the construction of petrochemical projects in Saudi Arabia are "Poor site management and supervision by contractors"; "Conflict between the main contractor and subcontractor"; "Poor planning and scheduling of projects by the contractor"; "Delays in material or equipment delivery"; and followed by "Delays in Handing Over Construction Site to the Contractor". This paper is original in the sense that the areas of knowledge and practice covered in the identified factors were distributed and not available in one source. The factors are derived from personal interviews with selected project managers, project engineers, construction supervisors, and the others from different positions in the project department and from the relevant literature.Energies 2018, 11, 1652 2 of 18 time delay and, consequently, causes millions of dollars in losses. Therefore, the goals of this research paper are to identify, assess, rank, and compare the most influencing factors causing schedule delays during the construction phase of petrochemical projects in Saudi Arabia. Research Problem and Significance of the Research.The main objectives of the project management team during the construction phase are to complete the project within its budget and on time and in accordance with specifications and quality requirements. Hence, identifying and ranking the factors that may cause schedule delays is essential in assisting the project management team to meet the above-stated objectives and to avoid delays. Due to its complexity, in recent years, many petrochemical projects were completed behind the targeted date that was agreed on between the owners and contractors. Such delays have significant consequences for the owners as well as the contractors. The delay during the construction phase is influenced by many factors that make meeting the set date a difficult task to the project management team. The literature reveals that very limited studies have reported on the identifying factors affecting the project schedule during the construction phase in petrochemical projects. This paper aims to identify, assess, rank, and compare the most influencing identified factors causing a delay in the petrochemical projects in the Eastern province of Saudi Arabia. The identification and ranking of such factors can assist owners, contractors, and the project management team of this class of projects in the following:

This paper presents a study conducted to identify, assess, rank, and compare the most influencing factors causing schedule delay during construction phase of petrochemical projects in Saudi Arabia. The methodology followed in this research to achieve the main aims is a combination of comprehensive review of the literature and interviewing number of local experts, which have resulted in identifying of 23 factors. Through a web-based questionnaire survey, the identified factors were ranked. Total of 90 completed responses were gathered from 106 received responses. The completed responses gathered from 38 contractors and 52 owners. Of 90 participants, there are 32 project managers, 22 project engineers, 7 construction supervisors and the other 31 having different positions in projects departments The study has found that the most influencing factors causing schedule delay during construction in petrochemical projects in Saudi Arabia are “Poor site management and supervision by contractors”; “Conflict between main contractor and subcontractor”; “poor planning and scheduling of projects by contractor”; “Delay of material or equipment delivery”; and followed by “Delay in Handing Over Construction Site to Contractor”. This paper is original in the sense that the areas of knowledge and practice covered in the identified factors were distributed and not available in one source. The factors are derived from personal interviews with selected project managers, project engineers, construction supervisors and the others from different positions in project department and from the relevant literature.