Many stages of information systems projects developed in public institutions are defined by laws and regulations, which reduces management flexibility. In the particular case of Business Process Management (BPM) projects, it has even more influence since the business processes are also constrained by legislation. In this context, it is important to have a clear vision of what the project’s success means for all the stakeholders, what can impact the success, and how success should be evaluated. This paper presents the case of a BPM project of a public institution, where it is being implemented a new PRINCE2-based project management approach comprising success management activities. The preliminary results include a new model that integrates success management and the PRINCE2 methodology, as well as a set of success criteria and success factors identified for the project.