**Abstract**

Infrastructure construction projects are complex with a very long life-cycle, a complex organizational plan, a complex resource management, technical complexities, contractual complexities and macro-environmental factors. The complexity of an infrastructure project leads to the existence of interdependent risks, which are hard to anticipate and control. As the investment is major for these types of projects, the risks and opportunities are critical to the project success or failure, the risk factors need to be identified and analyzed before any decision-making process. While upfront planning is important, not all events and scenarios can be foreseen as the project can take several years to complete and may involve many companies and stakeholders. In this planning stage of the project, a robust risk analysis method is indispensable for identifying and analyzing the major risk and opportunity factors. In this paper, a formalized multi-criteria decision-making process is developed based on a strategic risk analysis in a complex environment: (1) in a very early stage and at a strategic level, (2) before the contracting phase in order to develop a risk allocation plan and negotiate it with the project owner.

**Keywords:** risk management, complex projects, infrastructure projects, environmental risk analysis, risk breakdown structure, multi-criteria analysis, decision-making process
