Information Systems (IS) projects have been increasingly interested in stakeholder management. In this paper, we are specifically interested in the stakeholder analysis and engagement in IS projects. Thus, we propose to move from a stakeholder relational perspective, anchored in recent studies on Social Network Theory, to a stakeholder relational and becoming ontology, anchored in Actor Network Theory (ANT). Based on this theory, we developed a conceptual and practical method to conduct stakeholder analysis and assess their engagement during the on-going project. We apply our conceptual and practical method on a longitudinal case study of an IS project called "The Pupitre Virtuel". Our contributions are twofold. First, we improve stakeholders' analysis and engagement in a project by shedding light on the dynamic and emergent nature of relationships, since we demonstrate that the nature, roles and relations among stakeholders co-evolve with the definition and trajectory of the project. Consequently, the project emerged also because of connections between heterogeneous stakeholders. Second, we are able to give managers a useful method by informing the project managers about where, when, and how to observe stakeholders' network of an IS project.