Resumen
Contractors are facing an increasing degree of complexity in their construction projects. Due to inadequately prepared project plans, they have been suffering significant losses during the execution of construction projects. One of the key disadvantages of such plans is that during the planning process, a construction project is mostly defined as a linear rather than a dynamic and complex process with a high degree of uncertainty. Therefore, a contractor who is in the planning phase of a construction project should consider the impact of the project characteristics on its implementation according to the elements of project complexity. In this research, we therefore first made an overview of the existing research related to the elements of project complexity. Based on the frequency of their occurrence in existing surveys, this paper singled out eight groups of complexity characteristics that contractors should be aware of during construction projects. After that, based on the frequency of occurrence in the existing surveys, fifteen elements of complexity were classified for each project complexity group. The research conducted among construction project managers identified key complexity elements of the construction project from the contractor?s perspective. Thereby, the classification of groups with the associated key elements determining the complexity of a construction project from the perspective of the contractor was performed. By properly analyzing the impact of key elements of complexity on project flow during the planning phase, contractors can be more successful when planning the project objectives to be performed.