Public administrations in Germany currently face challenges of cost reduction and modernization. Furthermore, Pan-European directives foster process harmonization and introduction of IT-supported and optimized processes. Hereby activity-based costing can be a useful instrument for process assessment and evaluation. Especially through the introduction of New Public Management and double-entry accounting Public Administrations in Germany now get the opportunity to use cost-centered accounting mechanisms to assess process performance and evaluate their activities in a holistic concept. Process Modeling can be a useful instrument to help the public administrations to structure their activities and capture information about them and thereby create a basis for activity-based costing. Therefore, the aim of this article is combining the domain specific process modeling method PICTURE and concept of activity-based costing for supporting Public Administrations in process assessment and evaluation.