As is the case for the core business, the demands for Facility Management have risen massively over the last years, especially given the fact that statutory requirements and increasing user demands with regards to comfort, security, and efficiency have changed. Facility Management is subject to an increased professionalisation, raising questions about necessary financial and human resources in order to ensure interruption-free and legal operation. Owners und operators of bigger real estate urgently need tools and aids for workload planning. These are only available at a limited capacity in Facility Management (FM).Given these developments, the authors were commissioned to work out a guideline on behalf of GEFMA (German Facility Management Association e.V.), creating the task force “Personalbemessung im FM”. This task force was accompanied by a research project which was financially supported by the Arbeitsgemeinschaft Technischer Abteilungen deutschsprachiger Hochschulen (ATA). The aim of this guideline is to show approaches for resource planning and to give a short overview over existing proceedings. The focus is set on maintenance and operation of buildings and technical equipment. The aim is to provide a scientifically established procedure, based on existing approaches by owners and operators, which will enable them to calculate the necessary resources.