The National Land Survey of Finland (NLS) is a government agency that maintains finnish property register and uses various administrative information systems that handle crucial data. To develop, manage, and maintain these systems, NLS follows a Business Technology Standard model and aims to publish its own production applications as open source software and use open source applications in development when possible. During the development of new information systems, NLS follows an agreed and approved management model and uses only components and software that meet development guidelines. Examples of such components are QGIS and PostgreSQL. However, if NLS needs to adopt and evaluate components that are not yet included in the development guidelines, it must evaluate associated open source projects, record and process considerations, and accept them in accordance with the change management process. To evaluate the maturity of open source projects, NLS has developed a tool that continuously evolves to reflect the needs of the organization. The tool is a checklist of criteria that can be used to assess the maturity of a project and compare it to similar products. The presentation explains the items in the tool and their significance as part of the metrics. The tool that NLS has developed could be valuable for individuals and companies in similar positions when evaluating open source projects for their needs. The experiences gained by NLS can also help improve weak points that open source software producers may not have considered in their own projects.