In this paper, the workflow for the quality assessment and assurance of modularized simulation models (Viedt et al., 2023) is utilized for the quality assessment of independent third-party simulation models in form of Functional Mock-up Units (FMUs). Besides the process of testing of third-party models, the paper discusses the required information exchange between the manufacturer and the end-user of the simulation models to allow quality assessment and execution in a co-simulation. The case study is based on the use case of a modular Solid Oxide Electrolysis (SOEL) plant. The co-simulation integrates third-party FMUs, such as a SOEL model, with in-house developed FMUs, including the water supply unit and the steam supply unit. A best practice for the quality assessment and exchange of simulation models is derived. This comprises the testing of the third-party models, their subsequent integration into the co-simulation as well as the definition of the information, that is required for the integration of an FMU into the co-simulation.