The construction sector suffers from flat or sometimes even falling productivity rates while it is one of the least digitalized sectors. A root cause, among others, is poor information management. Recently, the ISO 19650 series have been released to offer the construction industry a guideline for the organization and digitization of information in construction assets when building information modelling (BIM) is used. However, a uniform application of standards in projects is not recommended as it can hamper flexibility and versatility. An essential document of ISO 19650 is the BIM Execution Plan (BEP) which appears more and more often in projects that use BIM, aiming to facilitate information management. However, organizations struggle to set up a process to customize a BEP that fits the project's needs. Therefore, this research focuses on the BIM Execution Plan (BEP) and how this can be tailored to fit the needs of a project. In addition, this thesis focuses on the preparation phase of infrastructure projects where the post-contract BIM execution plan applies. To conduct this study, first, the literature was reviewed, and a questionnaire was distributed to practitioners to evaluate the literature's findings. Next, semi-structured and structured interviews captured the practitioners' perceptions. As a result, influencing project characteristics for the BEP customization were found, mostly related to a) The experience and capability of the involved parties, b) The existence and use of ICT systems in the project, and c) The clarity of the project' and client's needs. The main research result is a) a process for customizing a BEP based on a list of project characteristics and b) a decision support tool that practically captures this process. Both the process and the tool aim to help BEP authors and recommend the extent of development of the BEP contents as per the project's needs. The validation results of the decision support tool are encouraging. More specifically, the tool's results have a small deviation from what experts recommend without the tool.