Graph Based Engineering Systems

The research group Graph Based Engineering Systems (Graphing) develops software solutions for the modeling, simulation, and optimization of technical systems. A common feature of these software systems is the graphical approach to the modeling of applications and domains.

This is realized by using graph based models and graphical languages for which visualizations and editors are developed. Fields of application include energy system technology, production planning, error analysis and switch cabinet layout.

In addition to solutions for specific industrial applications, the group runs various research projects on models for graphical languages, their visualization and layout as well as simulation and optimization methods.


  • Optimization, simulation and economic assessment of energy systems with TOP-Energy®
  • Standardized and adaptive error analysis plus correction for production systems with QUICKSTEPS®
  • Model-based software development grounded on hierarchical state machines
  • Research on graphical model description languages and parametric 3D-models for deep drawing tools
  • Placement and routing algorithms for automated switch cabinet layout
  • In-house software framework for graph based engineering systems
  • Graphical domain-specific languages and layout algorithms

Research Projects


Comprehensive optimization of energy systems

The optimization of industrial energy systems reveals capabilities to increase efficiency, reduce emissions, and save costs. Optimization methods can be employed in different areas, from planning to daily operation of plants. Here, the optimization model must reflect all relevant aspects of the underlying energy system.

Methods and tools for energy system optimization from previous research projects will be enhanced to become ready for practical applications in the research project sOptimo+.

Funded by: Federal Ministry for Economic Affairs and Energy / EnEff: Wärme; funding code: 03ET1259C


Model-based energy controlling to close the energy efficiency gap between planning and operation of complex energy systems, demonstrated on non-residential buildings

Energy efficiency is simultaneously an important competitive advantage for companies and a political claim in the public area. Predicted energy savings during planning often do not correspond to the actual reductions achieved in operation, i.e. there is a gap between planning and operation. The goal of the research project is to develop a method to close this gap by employing models of the underlying energy systems.

Funded by: Federal Ministry for Economic Affairs and Energy / IGF; funding code: 18280 BG/3


Development of a quality system for the content appraisal of 8D-Reports

8D-Reports are created to document the handling of claims between customer and manufacturer. This research projects develops a system for the formal and textual appraisal of 8D-Reports to raise their quality. Automatic evaluation can lead to the identification of low quality reports and help in executing a valuable claim management process.

Funded by: Federal Ministry for Economic Affairs and Energy / IGF; funding code: 18447 N


Method for the Model Driven Design of CAD Models for Deep Drawing Tools

Fully parametric 3D CAD modelling is state of the art in modern engineering. Finished product models include a multitude of information in addition to geometrical data. However, designing such a model involves the precise planning and modelling of all the parameter relations between individual parts. High time and cost pressure make this approach undesirable for many design engineers.

While modern CAD systems offer a high degree of automation and simplification of some designer tasks, they fail to present the functional interactions at the required level of abstraction particularly in the early phases of developing sheet metal tools. IFUM (Institute of Forming Technology and Machines, Leibniz University Hannover) and GFaI-Graphing have developed a new method for the model-driven design of deep drawing tools. The main component of this method is a new graphical modelling language based on SysML. With the help of this graphical language, parameter relations can be defined in earlier developing phases of deep drawing tools.

Funded by: DFG; funding code: PL 706/1-1 und BE 1691/164-1