Nuclear infrastructure development projects are increasing in complexity, involving numerous and various stakeholders. Highly constrained, they are often subject to many hazards. This has an impact on the number of desired design alternatives generated throughout the facility life cycle and their evolving assessment. In order to secure the delivery of such projects, the Évaluation for Critical Infrastructures Model-based system Engineering (EVA-CIME) method is proposed to implement and operate the architecture evaluation at the scales both of an organization and of projects. This article presents the elements justifying the formalization of such method and the obstacles to overcome. This method must be technically and organizationally usable by the different actors of a nuclear infrastructure development project. It is composed of 5 elements: concepts; languages; operational approach; tools and repository of knowledge and expertise. The good orchestration of these different components allows to set up an environment within the organization to carry out effective architecture evaluations with the aim of helping the architects to choose between the alternatives that they will imagine from the beginning of the project.