Regression testing is a commonly used strategy in continuous integration workflows to ensure reproduceability of outputs. It is widely in software engineering and model development, including Modelica. In this article we introduce the open source regression testing framework MoPyRegtest written in Python. Its primary focus is to provide Modelica library developers with a simple regression testing tool that features test automation and can integration with continuous integration toolchains, in particular for open source developments. In order to simulate the Modelica models for testing analysis, we provide an interface to Modelica simulation tools that support Modelica Scripting with .mos files. Our current implementation works with OpenModelica. We outline the design and functionality of MoPyRegtest and showcase its potential usefulness for open source development of Modelica models and libraries.

System simulation is dealing with increasingly multiphysical and cyber-physical systems that involve multiple engineering domains. In development and production, system manufacturers often rely on supplier parts and their digital representations. To deal with this inherently collaborative setting in a more efficient way we propose a concept of Simulation Model as a Service (SMaaS) developed at simercator. In this article, we apply established workflows from software engineering to system simulation to create more efficient workflows, discuss the compliance with technical, economic, and regulatory requirements, and present a software for digital supply chain management that implements SMaaS.

5th generation district heating and cooling networks (5GDHC) are a relatively new concept. They are based on the idea that a single district loop at a ambient tem-

perature range can be used for heating and cooling simultaneously. This paper improves on a 5GDHC called the reservoir network. The study updates the sewage heat exchanger plant model to more realistically represent seasonal changes, uses the novel pump models with variable efficiency, introduces a ground coupled district pipe model to consider the inertia of the district network and a new control strategy for storage and sewage heat exchanger was implemented. the new approach reduced operating costs, mainly due to pumping cost for storage, sewage

heat exchanger plant and distribution pump, while increasing the overall robustness of the approach in different sizing conditions. Thanks to the new controller, the pumping consumption was reduced by 21% with respect to the baseline, while showing that the approach is robust against design changes such as reduction in borehole field size and increasing the sewage heat exchanger size, since the

pumping energy savings become 29%. Lastly borehole field temperature stability was analyzed through a 40Y simulation.

This paper introduces MARCO, a research compiler aimed at the efficient generation of efficient simulation code from a large-scale Modelica model. MARCO’s design goals, requirements, and specifications are dis- cussed in the paper, as well as the software architec- ture, the current development status, and a future develop- ment roadmap. The results of two test cases demonstrate MARCO’s capability to handle non-trivial Modelica mod- els with over 10 million equations very efficiently.